Jakob Begun - Academia.edu (original) (raw)

Papers by Jakob Begun

Research paper thumbnail of P037 Enhancing the efficacy of cannabidiol using protein nanoparticles to treat inflammatory bowel disease

Journal of Crohn's and Colitis, Jan 30, 2023

Research paper thumbnail of Faecal calprotectin testing for identifying patients with organic gastrointestinal disease: systematic review and meta‐analysis

The Medical Journal of Australia, Nov 1, 2019

We reviewed the clinical effectiveness of FC testing for distinguishing organic GID from function... more We reviewed the clinical effectiveness of FC testing for distinguishing organic GID from functional GIDs compared with specialist diagnoses based on combinations of clinical, laboratory, imaging, and endoscopic findings. We assessed both its effectiveness for distinguishing between patients with organic GIDs who require further investigation and patients with functional GIDs, and for distinguishing between patients with IBD and those with functional GIDs, a common clinical problem. Methods Our study was conducted in accordance with the Preferred Items for Systematic Reviews and Meta-analysis [PRISMA] guidelines. 18 Our systematic review was registered with

Research paper thumbnail of P614 Reduction of bowel wall thickness and doppler signals as early as 36 hours predicts corticosteroid response in a multi-centre prospective cohort of Acute Severe Ulcerative Colitis: USUC Study including the GENIUS cohort

Journal of Crohn's and Colitis, Jan 30, 2023

Background: Gastrointestinal ultrasound (GIUS) can accurately assess disease activity in atients ... more Background: Gastrointestinal ultrasound (GIUS) can accurately assess disease activity in atients with ulcerative colitis (UC). The aim of this study was to determine the accuracy of GIUS in predicting IV corticosteroid (CS) failure in patients with Acute Severe Ulcerative Colitis (ASUC) and the requirement for rescue therapy.

Research paper thumbnail of P523 Endoscopic balloon dilatation is safe and has a high success rate in patients with stricturing Crohn’s disease

Journal of Crohn's and Colitis, Jan 25, 2019

Research paper thumbnail of The impact of clinical experience on decision-making regarding the treatment and management of mild-to-moderate ulcerative colitis

Intestinal Research, Jan 31, 2023

tion was more common among inflammatory bowel disease (IBD) specialists than general gastroentero... more tion was more common among inflammatory bowel disease (IBD) specialists than general gastroenterologists. 2 To further investigate how clinical experience influences decision-making in UC, we assessed this aspect in a sub-analysis of our study. The study methodology and participation have been fully described elsewhere. 1 In brief, 157 factors potentially related to the management of patients with mild-to-moderate UC were cataloged across 2 meetings with 11 IBD specialists from different countries (Supplementary File 1). This catalog formed the basis of a structured, online questionnaire that objectively assessed the importance and contribution of each of the factors when considering one of 3 defined scenarios: (1) when your patient presents with active mild-to-moderate UC; (2) when your patient achieves remission following a mild-tomoderate UC flare; and (3) self-management and empowerment of patients with mild-to-moderate UC (Supplementary File 1). For each scenario, individual factors were scored on

Research paper thumbnail of OP36 Investigating the role of bioactives produced by gut bacteria to modulate immune response in inflammatory bowel disease

Journal of Crohn's and Colitis, 2020

During 2010 to 2016, 2-year surgery rates in CD patients showed a non-significant decline from 11... more During 2010 to 2016, 2-year surgery rates in CD patients showed a non-significant decline from 11.9% in 2011 to 9.5% in 2016 in SWE while remaining stable in NOR and DEN (Figure 1). No temporal pattern in surgery risk was observed for UC. The proportion of CD patients being hospitalised within two years from diagnosis declined in SWE and NOR from 52.3% and 51.0% in 2011 to 47.3% and 38.5% in 2015 (p < 0.001), respectively, while hospitalisation in UC remained stable. In contrast, 2-year hospitalisation rates in DEN increased in CD from 27.0% in 2011 to 31.5% in 2016 (p = 0.045) and similarly in UC from 20.4 to 35.0% (p < 0.001), respectively (Figure 2). Conclusion: No clear pattern was seen in two-year surgery and hospitalisation rates in IBD patients during 2010 to 2017 despite a concurrent increase in biological use in all countries. However, differences in treatment practices across countries might influence these findings. The impact of increased biological use on long-term outcomes in IBD remains to be shown.

Research paper thumbnail of Modelling the benefits of an optimised treatment strategy for 5-ASA in mild-to-moderate ulcerative colitis

BMJ Open Gastroenterology, Feb 1, 2022

et al. Modelling the benefits of an optimised treatment strategy for 5-ASA in mild-to-moderate ul... more et al. Modelling the benefits of an optimised treatment strategy for 5-ASA in mild-to-moderate ulcerative colitis.

Research paper thumbnail of POS0431 Goblet Cell Specific Anti-Apoptotic Role of INTERLEUKIN-24 in Spondyloarthritis-Associated Ileitis

Annals of the Rheumatic Diseases, May 30, 2023

Background: The role of B cells in the pathogenesis of ankylosing spondylitis (AS) remains relati... more Background: The role of B cells in the pathogenesis of ankylosing spondylitis (AS) remains relatively understudied. Nevertheless, available evidence shows presence of B cells at sites of inflammation, higher frequencies of circulating plasmablasts, presence of autoantibodies and beneficial results of B cell depleting therapy with rituximab [1]. We observed previously that a subpopulation of CD27-B cells, characterized by low expression of the complement receptor CD21 (CD21 low), is increased in patients with AS and patients with primary Sjogren's syndrome (pSS), a typical B cell mediated systemic autoimmune disease [2]. These CD21 low CD38 low CD27-B cells display a pro-inflammatory phenotype, suggestive for a pathogenic role. Objectives: To gain insight into the origin of these CD21 low CD38 low CD27-B cells we analysed the mutation status of the immunoglobulin heavy chain variable (IGHV) gene regions in the total B cell compartment, CD21 low B cell subpopulations and plasmablasts in AS patients in comparison to pSS patients and healthy donors (HD). In addition, we investigated clonal relations between CD21 low B cell subpopulations and plasmablasts in AS. Methods: RNA was isolated from sorted total B cells (CD19 +), two CD21 low B cell populations (CD21 low CD38 low CD27and CD21 low CD38 low CD27 +) and plasmablasts (CD19 + CD38 ++ CD27 +) from peripheral mononuclear cells of 10 AS patients fulfilling the mNY criteria (mean age 46 ± 9 years, 60% male, mean ASDAS 2.3 ± 0.8, all HLA-B27+), 10 sex-and age-matched HDs (mean age 48 ± 21 years, 60% male) and 10 age-matched pSS patients (mean age 46 ± 9 years, 20% male). Repertoire analysis of the B cell receptor heavy chain was performed using high throughput sequencing on the Illumina MiSeq Platform. Sequences were analyzed for degree of somatic hypermutation, usage of immunoglobulin heavy chain variable (IGHV) and joining (IGHJ) regions and clonal relationships. Results: IGHV sequences with identical heavy chain CDR3 regions were grouped together and were defined as a clone. Analysis of the IGHV mutation status in CD21 low B cells revealed that the majority of clones (71% SD ± 14.1) in the CD21 low CD38 low CD27subset from patients with AS consisted of clones with a low mutation rate (0-2 mutations in the IGHV region) (Figure 1b). On the contrary, most of the clones in the CD21 low CD38 low CD27 + (49% SD ± 12.5) and plasmablasts (59% SD ± 12.7) subsets were clones with a higher mutation load (>10 mutations in the IGHV region). A similar mutational pattern was seen in pSS patients and HDs. In AS, IGHV3 and IGHJ4 family genes were predominantly used (Figure 1c). However, we observed no differences in family gene usage among B cell subsets nor between groups. To investigate clonal relationships we performed a CDR3 amino acid network analysis on the top 100 most expanded clones per subset in AS patients and found that the CD21 low CD38 low CD27subset shared more clones with the CD21 low CD38 low CD27 + subset (median 3.0 (0.8-7.0 IQR), p< 0.05) compared to plasmablasts (median 0.0 (0-1.3 IQR). Conclusion: This study shows that the expanded circulating CD21 low CD-38 low CD27-B cell population in AS consists mainly of antigen-inexperienced cells. The presence of shared clones with their CD27 + counterpart and plasmablasts suggest that the three subsets are to some extent related. Hence, CD21 low CD38 low CD27-B cells may differentiate towards CD21 low CD38 low CD27 + B cells and plasmablasts. The relative roles of these CD21 low B cell subsets and plasmablasts in AS pathogenesis remain to be established. REFERENCES: [1] Wilbrink, R et al. (2021). B Cell Involvement in the Pathogenesis of Ankylosing Spondylitis. International journal of molecular sciences. [2] Wilbrink, R et al. (2021). CD27-CD38 low CD21 low B-Cells Are Increased in Axial Spondyloarthritis. Frontiers in immunology. Figure 1.

Research paper thumbnail of P663 Post-ustekinumab induction IL12, IL23, and ustekinumab levels are associated with clinical response in a multi-centre prospective cohort study of Crohn’s disease patients: results from the AURORA Study including ANZIBDC Cohort

Journal of Crohn's and Colitis

Background Ustekinumab (UST) is a monoclonal antibody targeting IL-12 and IL-23 through their sha... more Background Ustekinumab (UST) is a monoclonal antibody targeting IL-12 and IL-23 through their shared p40 subunit. This study aimed to determine the clinical outcomes after UST treatment in Crohn’s disease (CD) patients in a real-world setting, and to investigate the association of clinical outcomes with IL-12, IL-23 and UST levels. Methods A multi-centre prospective observational cohort study of UST for moderate to severe CD was conducted. Patients were recruited from 19 Australian centres between Sep 2019 and Apr 2022. Clinical assessments were performed at baseline study visit (SV) 1 and post-induction (SV2). Patients were assessed every 6 months during maintenance therapy to 18 months (SV4). Clinical response and remission rates were determined using PRO2 definitions (STRIDE II guidelines). Logistic regression analyses were performed to identify predictors of clinical response and remission. UST levels were measured post induction and interleukin levels including IL12p40 and IL-2...

Research paper thumbnail of S804 Pilot Study to Assess Pharmacokinetic and Pharmacodynamic Markers Following Enema-Dosing With Adalimumab in Patients With Active Ulcerative Colitis (UC)

American Journal of Gastroenterology

Research paper thumbnail of An inhibitor of Wnt protein production improves host control of Listeria monocytogenes

European Journal of Immunology, 2016

also previously shown that protein kinase C (PKC) βII is essential for DC differentiation and tha... more also previously shown that protein kinase C (PKC) βII is essential for DC differentiation and that tumor derived factors, particularly IL-6, inhibit DC differentiation by repressing the expression of PKCβII through a Stat3 dependent mechanism. However, the pathways activated downstream of PKCβII during DC differentiation have yet to be fully characterized. To study this, we used the K562 cell line, which differentiates into DCs with addition of PMA, a known chemical activator of conventional PKC isoenzymes. We have also shown previously that PMA specifically activates PKCβII in K562 cells. Addition of PMA to K562 cells showed the activation of the ERK1/2 and NFκB pathways, including both the canonical and non-canonical NFκB pathways. Chemical inhibition of either the ERK1/2 or NFκB pathway yielded immature DCs with a reduced capacity to stimulate T-cell proliferation when incubated with PMA. Inhibition of ERK1/2 also showed a change in levels of RelB, a NFκB transcription factor, with PMA treatment and during PMA induced DC differentiation. Inhibition of either the ERK1/2 or NFκB pathways showed an increase in Foxo3a levels, indicating a role for the ERK1/2 and NFκB pathways in Foxo3a regulation during differentiation into mature DCs. Taken together, these results show an integral role for both the ERK and NFκB pathways downstream of PKCβII activation during DC differentiation.

Research paper thumbnail of MUC1-mediated Macrophage Activation Promotes Colitis-associated Colorectal Cancer via Activating the Interleukin-6/ Signal Transducer and Activator of Transcription 3 Axis

Cellular and Molecular Gastroenterology and Hepatology

Research paper thumbnail of Invention of a Genetic Toolkit for Immunomodulatory Gut Bacteria to Expedite the Development of New Crohn's Disease Therapeutics

The public reporting burden for this collection of information is estimated to average 1 hour per... more The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188),

Research paper thumbnail of Tu1020 - Crohn's Colitis Care (CCcare) - Development and Testing of a Bespoke Cloud-Based Clinical Management System for Inflammatory Bowel Disease (IBD)

Gastroenterology, 2018

BACKGROUND: Fecal microbiota transplantation (FMT) can restore gut microbiota diversity and patho... more BACKGROUND: Fecal microbiota transplantation (FMT) can restore gut microbiota diversity and pathogen colonization resistance in patients with recurrent CDI. OBJECTIVE: The study compared improvement in fecal a and b diversity in subjects with recurrent CDI following FMT by lower GI administration (retention enema with frozen product) versus upper GI route (oral administration of lyophilized product in enteric coated capsules). METHODS: Microbiome analysis was performed on fecal samples from 39 subjects, 21 randomized to receive frozen FMT (100 g original fecal product) by retention enema and 18 to lyophilized FMT in enteric coated capsules (100 g or 200 g fecal product). Stool collected before FMT, 2, 30 and 90 days after FMT were analyzed for microbiome studies sequencing the variable 4 region of the 16S ribosomal-RNA gene on the Illumina MiSeq platform. RESULTS: Cure rates from subsequent bouts of CDI were similar in both treatment groups 18/21 (86%) for enema and 17/18 (94%) receiving capsules (P=0.61). Microbiota diversity, as measured by the inverse Simpson index, showed low baseline diversity in the 39 subjects with CDI pre-FMT, with minor improvement by day 2, after transplantation, and near complete recovery by day 30 in both treatment groups. Using UniFrac distances, we found that of recipients of frozen product by enema on Day 2 had more rapidly changed towards their FMT donors (median Day 2 UniFrac distance 0.51 vs 0.59 in lyophilized oral recipients, p=0.0003), indicating that a frozen enema was more effective at normalizing the microbiome at an early stage. Examining the major taxonomical subsets of intestinal bacteria, we found that while Clostridia were efficiently transferred by both treatment modalities, Bacteroidia and Verrucomicrobia were less efficiently transferred by lyophilized oral FMT. CONCLUSIONS: Both FMT products (lyophilized or frozen) were effective in curing CDI recurrences but differed in their ability to restore the full breadth of the intestinal microbiome. The findings raise the possibility that spore-forming organisms such as Clostridia may be a more important subpopulation for the efficacy of FMT in treating recurrent CDI. In previous studies using lyophilized product given to subjects with CDI by colonoscopy, we did not observe a reduction in Bacteroidia or Verrucomicrobia, suggesting that small bowel factors, digestive enzymes and bile salts may have influenced the microbiota associated with lyophilized FMT product given orally. Tu1020 CROHN'S COLITIS CARE (CCCARE)-DEVELOPMENT AND TESTING OF A BESPOKE CLOUD-BASED CLINICAL MANAGEMENT SYSTEM FOR INFLAMMATORY BOWEL DISEASE (IBD)

Research paper thumbnail of Sa1828 - Enteropathogens Detected on Stool Culture and Multiplex PCR are a Common Finding in Inflammatory Bowel Disease Patients

Research paper thumbnail of Crohn’s Colitis Care (CCCare): bespoke cloud-based clinical management software for inflammatory bowel disease

Scandinavian Journal of Gastroenterology, 2020

Abstract Background Adherence to evidence-based management is variable in inflammatory bowel dise... more Abstract Background Adherence to evidence-based management is variable in inflammatory bowel disease (IBD), which leads to worse patient outcomes and higher healthcare utilization. Solutions include electronic systems to enhance care, but these have often been limited by lack of clinician design input, poor usability, and low perceived value. A cloud-based IBD-specific clinical management software – ‘Crohn’s Colitis Care’ (CCCare) was developed by Australia and New Zealand Inflammatory Bowel Disease Consortium clinicians and software developers to improve this. Methods CCCare captures patient-reported disease activity and medical assessment, medication monitoring, cancer screening, preventative health, and facilitates communication with the IBD team and referring doctor. De-identified longitudinal data are stored separately in a clinical quality registry for research. CCCare was tested for feasibility and usability in routine clinical settings at two large Australian hospitals. Users’ experience was evaluated with System Usability Scale (SUS). Value to clinicians and patients was assessed by qualitative feedback. Security was assessed by penetration testing. Results Users (n = 13; doctors, nurses, patients) reported good usability and learnability (mean SUS score 75 (range 50–95), sub-scores were 77 (50–94) and 68 (38–100), respectively). Patients reported better communication with clinical team and greater ability to track disease. Clinicians highlighted structured management plans, medication adherence, and centralised data repository as positive features. Penetration testing was passed successfully. Conclusions Initial evaluation demonstrates CCCare is usable, secure, and valued in clinical use. It is designed to measure outcomes of clinical care, including efficacy, quality, cost, and complications for individuals, and to audit these at hospital and national level.

Research paper thumbnail of Practical management of inflammatory bowel disease patients during the COVID‐19 pandemic: expert commentary from the Gastroenterological Society of Australia Inflammatory Bowel Disease faculty

Internal Medicine Journal, 2020

The COVID‐19 pandemic, caused by the novel coronavirus SARS‐CoV‐2, has emerged as a public health... more The COVID‐19 pandemic, caused by the novel coronavirus SARS‐CoV‐2, has emerged as a public health emergency and challenged healthcare systems globally. In a minority of patients, SARS‐CoV‐2 manifests with a severe acute respiratory illness and currently there are insufficient data regarding the virulence of COVID‐19 in inflammatory bowel disease patients taking immunosuppressive therapy. This review aims to summarise the current literature and provide guidance on the management of inflammatory bowel disease (IBD) patients in the context of the COVID‐19 pandemic in the Australasian setting.

Research paper thumbnail of P328 Crohn’s colitis care (CCCare): development and testing of a bespoke cloud-based clinical management system for inflammatory bowel disease (IBD)

Journal of Crohn's and Colitis, 2018

Background: With improved therapy, patients with inflammatory bowel disease(IBD) often embark upo... more Background: With improved therapy, patients with inflammatory bowel disease(IBD) often embark upon overseas travel. Pre-travel risk management for infections, venous thromboembolism (VTE) and potential for flares might be appropriate. However, there are few data regarding these recommendations and heterogeneity in recommendations is likely related to different levels of immunosuppression, duration of flight and travel origin. Methods: Gastroenterologists from Australia (AUS) and Asia-Pacific (AP) region completed a web-based structured questionnaire evaluating travel topics such as pre-travel vaccination, VTE prophylaxis, and managing travellers' diarrhoea or IBD flares. Scenario-based responses on potential tuberculosis(TB) exposure in those with low-(azathioprine, vedolizumanb) vs. high-level (anti-tumour necrosis factor) immunosuppression were obtained. We hypothesised there were no differences between AUS and AP doctors' recommendations. Our primary endpoints were differences between AUS and AP respondents. Results: A total of 92 surveys were obtained (response rate 60%, AUS, n = 58, AP, n = 17, mean 12.9(±10.7) years of experience). Half of all respondents saw >6 IBD patients per week. More than 65% of respondents covered all travel-related topics (AUS vs. AP, p = ns) but significantly more AUS respondents discussed vaccinations than AP respondents (88% vs. 77%, p = 0.04, Table 1). Up to 65% of respondents recommended malaria prophylaxis, and advised against yellow fever (p = 0.17) and BCG vaccination (p = 0.29, Table 2). 71% of AUS respondents advised high-level immunosuppressed patients not to travel to TB-endemic area, compared with 12% of AP respondents (p < 0.01). Up to 88% of respondents disagreed with TB prophylaxis antibiotics (p = 0.89), stopping immunosuppressives (p = 0.37) prior to TB endemic countries, with AUS respondents trended to recommend pre-/post-travel CXR (p = 0.08) and not tuberculin skin test (p = 0.14). Interferon-Gamma Release Assay was preferred by AUS respondents (p < 0.01) (Table 3). Only 22% of respondents recommended anticoagulation for VTE prophylaxis. No predictors of VTE use were identified. Appropriate travellers' diarrhoea advice was provided by both groups. Conclusions: AUS physicians were more risk-averse compared with AP physicians regarding potential TB exposure. There were no differences in recommendations on VTE prophylaxis, vaccinations or management of infectious diarrhoea or IBD flares between the two regions. Travel-related consensus guidelines are likely, therefore, to be relevant for both regions.

Research paper thumbnail of Tu1302 INVESTIGATING THE ROLE OF BIOACTIVES PRODUCED BY GUT BACTERIA TO MODULATE IMMUNE RESPONSE IN IBD

Gastroenterology, 2020

Background: Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition of the gastroint... more Background: Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract. Although the pathogenesis of IBD is not fully understood, it is believed to result from the interaction between various genetic and environmental factors, including the microbiome, resulting in inappropriate gut inflammation. Under homeostatic conditions, the gut immune system exists in a tolerogenic state with the microbiota. However, microbial dysbiosis and an imbalance of pro-and anti-inflammatory cytokines in the gut characterise IBD and recently faecal microbiota transplantation studies have demonstrated that manipulation of the microbiome can induce remission. In this study, the ability of bioactives produced from single species of anaerobic gut bacteria cultured from healthy human faecal samples to modulate NF-kB activity was investigated, their biochemical properties were assessed and their ability to alleviate colitis was also investigated. Methods: The NF-kB suppressive effects of culture supernatants (CSs) from 23 different isolates were tested on colonic epithelial cell lines. Suppressive CSs were also tested on human-derived colonic organoids from IBD patients and healthy controls and IL-8 expression was measured. Furthermore, CS from AHG0001 strain was also tested in spontaneous colitis model Winnie in vivo. The supernatant was further characterised by extraction in multiple solvents and fractionated through reversedphase analytic HPLC column to test for suppressive fractions and further investigate their chemical characteristics. Results: LS174T and Caco-2 reporter cells stimulated with TNF a and IL-1b respectively, resulted in NF-kB activation. Of the 23 isolates screened, CS from five isolates significantly suppressed NF-kB activation. The selected CSs also suppressed IL-8 secretion in PBMCs and gut organoids from both UC and CD patients, as well as healthy controls, with notable individual variation. Rectal gavage of CS from AHG0001 also reduced disease activity, improved histologic inflammation and reduced the proinflammatory gene expression in Winnie mice. Furthermore, a potent small molecule (IC50=3nM) produced by AHG0001 was also identified through bioassay guided solvent extractions and filtrations, followed by UPLC-QTOF and comparative metabolomics. Conclusions: Our anaerobic culturing and NF-kB reporter assay system allows for the rapid identification of bacteria producing immunomodulatory bioactives, which could lead to the future development of novel therapeutics. Our in vivo and ex vivo testing utilising spontaneous colitis model and patient derived organoids demonstrates the potential of precision medicine-based approaches for bacterial based therapeutics.

Research paper thumbnail of Sa1913 CONSENSUS GUIDELINES FOR THE REGULATION, PRODUCTION AND USE OF FECAL MICROBIOTA TRANSPLANTATION IN CLINICAL PRACTICE

Gastroenterology, 2020

Background: Methane (CH 4) production has been associated with a number of clinical conditions bu... more Background: Methane (CH 4) production has been associated with a number of clinical conditions but remains poorly studied due to a reliance on breath CH 4 measurements for characterization of CH 4 and non-CH 4 producers. Therefore, we explored the relationship between the abundance of methanogenic archaea (methanogens) and CH 4 production in vitro in an effort to identify quantitative molecular thresholds that can be used to differentiate CH 4 and non-CH 4 producers. Methods: Fecal samples were collected to assess intestinal microbial composition and to evaluate concentrations of CH 4. Samples were processed within 2 hours of collection. Quantitative PCR (qPCR) was performed targeting the mcrA gene, which encodes the alpha subunit of methyl coenzyme M reductase (enzyme that catalyzes final step in methanogenesis). qPCR data was corrected for wet stool weight. Highthroughput DNA sequencing, targeting the V4 region of the 16S rRNA gene, was performed to determine relative abundance of Euryarchaeota. Up to 40g of sample was homogenized with phosphate-buffered saline in a blender pre-purged with nitrogen gas. Ten grams of this material was transferred to gas-tight septum jars, purged with nitrogen gas, and incubated at 37°C for 2 hours. After incubation, 2 mL gas samples were injected into a gas chromatograph with a flame ionization detector for CH 4 measures. Calibration gases were used as standards. Dry weight of the sample was calculated by loss on drying method after heating at 68°C for ‡24 hours. CH 4 measures were corrected to ppm/g dry weight of stool. Receiver operating characteristic analysis was used to generate detection thresholds. Results: Thirtythree samples from unique individuals were included in the analysis. Of these, ten were found to be CH 4 producers. Total mcrA gene copies correlated with CH 4 gas production (R=0.53; Figure 1). The detection threshold for CH 4 production was calculated to be 5.1x10 5 mcrA gene copies per gram feces. Methanobrevibacter was the most abundant methanogen group and its relative abundance provides a clear distinction between methane and nonmethane producers (Table 1). Its detection threshold for CH 4 production was calculated to be 0.089%. A positive trend was observed between the relative abundance of Methanobrevibacter (%) and CH 4 gas production values (R=0.45). A strong correlation (R=0.95) was observed between total mcrA gene copies (per g feces) and total relative abundance (%) of methanogens within Euryarchaeota. Conclusions: A threshold of 5.1x10 5 mcrA gene copies per gram feces or a Methanobrevibacter relative abundance of ‡0.089% are reliable biomarkers of intestinal CH 4 production capacity. Identification of these thresholds provides a means for molecular assessment of CH 4 production capacity and can potentially facilitate a wide range of clinical research without the need for cumbersome gas measurements. S-477 AGA Abstracts Total mcrA gene copies correlated with CH 4 gas production (R=0.53). The detection threshold for CH 4 production was calculated to be 5.1x10 5 mcrA gene copies per gram feces.

Research paper thumbnail of P037 Enhancing the efficacy of cannabidiol using protein nanoparticles to treat inflammatory bowel disease

Journal of Crohn's and Colitis, Jan 30, 2023

Research paper thumbnail of Faecal calprotectin testing for identifying patients with organic gastrointestinal disease: systematic review and meta‐analysis

The Medical Journal of Australia, Nov 1, 2019

We reviewed the clinical effectiveness of FC testing for distinguishing organic GID from function... more We reviewed the clinical effectiveness of FC testing for distinguishing organic GID from functional GIDs compared with specialist diagnoses based on combinations of clinical, laboratory, imaging, and endoscopic findings. We assessed both its effectiveness for distinguishing between patients with organic GIDs who require further investigation and patients with functional GIDs, and for distinguishing between patients with IBD and those with functional GIDs, a common clinical problem. Methods Our study was conducted in accordance with the Preferred Items for Systematic Reviews and Meta-analysis [PRISMA] guidelines. 18 Our systematic review was registered with

Research paper thumbnail of P614 Reduction of bowel wall thickness and doppler signals as early as 36 hours predicts corticosteroid response in a multi-centre prospective cohort of Acute Severe Ulcerative Colitis: USUC Study including the GENIUS cohort

Journal of Crohn's and Colitis, Jan 30, 2023

Background: Gastrointestinal ultrasound (GIUS) can accurately assess disease activity in atients ... more Background: Gastrointestinal ultrasound (GIUS) can accurately assess disease activity in atients with ulcerative colitis (UC). The aim of this study was to determine the accuracy of GIUS in predicting IV corticosteroid (CS) failure in patients with Acute Severe Ulcerative Colitis (ASUC) and the requirement for rescue therapy.

Research paper thumbnail of P523 Endoscopic balloon dilatation is safe and has a high success rate in patients with stricturing Crohn’s disease

Journal of Crohn's and Colitis, Jan 25, 2019

Research paper thumbnail of The impact of clinical experience on decision-making regarding the treatment and management of mild-to-moderate ulcerative colitis

Intestinal Research, Jan 31, 2023

tion was more common among inflammatory bowel disease (IBD) specialists than general gastroentero... more tion was more common among inflammatory bowel disease (IBD) specialists than general gastroenterologists. 2 To further investigate how clinical experience influences decision-making in UC, we assessed this aspect in a sub-analysis of our study. The study methodology and participation have been fully described elsewhere. 1 In brief, 157 factors potentially related to the management of patients with mild-to-moderate UC were cataloged across 2 meetings with 11 IBD specialists from different countries (Supplementary File 1). This catalog formed the basis of a structured, online questionnaire that objectively assessed the importance and contribution of each of the factors when considering one of 3 defined scenarios: (1) when your patient presents with active mild-to-moderate UC; (2) when your patient achieves remission following a mild-tomoderate UC flare; and (3) self-management and empowerment of patients with mild-to-moderate UC (Supplementary File 1). For each scenario, individual factors were scored on

Research paper thumbnail of OP36 Investigating the role of bioactives produced by gut bacteria to modulate immune response in inflammatory bowel disease

Journal of Crohn's and Colitis, 2020

During 2010 to 2016, 2-year surgery rates in CD patients showed a non-significant decline from 11... more During 2010 to 2016, 2-year surgery rates in CD patients showed a non-significant decline from 11.9% in 2011 to 9.5% in 2016 in SWE while remaining stable in NOR and DEN (Figure 1). No temporal pattern in surgery risk was observed for UC. The proportion of CD patients being hospitalised within two years from diagnosis declined in SWE and NOR from 52.3% and 51.0% in 2011 to 47.3% and 38.5% in 2015 (p < 0.001), respectively, while hospitalisation in UC remained stable. In contrast, 2-year hospitalisation rates in DEN increased in CD from 27.0% in 2011 to 31.5% in 2016 (p = 0.045) and similarly in UC from 20.4 to 35.0% (p < 0.001), respectively (Figure 2). Conclusion: No clear pattern was seen in two-year surgery and hospitalisation rates in IBD patients during 2010 to 2017 despite a concurrent increase in biological use in all countries. However, differences in treatment practices across countries might influence these findings. The impact of increased biological use on long-term outcomes in IBD remains to be shown.

Research paper thumbnail of Modelling the benefits of an optimised treatment strategy for 5-ASA in mild-to-moderate ulcerative colitis

BMJ Open Gastroenterology, Feb 1, 2022

et al. Modelling the benefits of an optimised treatment strategy for 5-ASA in mild-to-moderate ul... more et al. Modelling the benefits of an optimised treatment strategy for 5-ASA in mild-to-moderate ulcerative colitis.

Research paper thumbnail of POS0431 Goblet Cell Specific Anti-Apoptotic Role of INTERLEUKIN-24 in Spondyloarthritis-Associated Ileitis

Annals of the Rheumatic Diseases, May 30, 2023

Background: The role of B cells in the pathogenesis of ankylosing spondylitis (AS) remains relati... more Background: The role of B cells in the pathogenesis of ankylosing spondylitis (AS) remains relatively understudied. Nevertheless, available evidence shows presence of B cells at sites of inflammation, higher frequencies of circulating plasmablasts, presence of autoantibodies and beneficial results of B cell depleting therapy with rituximab [1]. We observed previously that a subpopulation of CD27-B cells, characterized by low expression of the complement receptor CD21 (CD21 low), is increased in patients with AS and patients with primary Sjogren's syndrome (pSS), a typical B cell mediated systemic autoimmune disease [2]. These CD21 low CD38 low CD27-B cells display a pro-inflammatory phenotype, suggestive for a pathogenic role. Objectives: To gain insight into the origin of these CD21 low CD38 low CD27-B cells we analysed the mutation status of the immunoglobulin heavy chain variable (IGHV) gene regions in the total B cell compartment, CD21 low B cell subpopulations and plasmablasts in AS patients in comparison to pSS patients and healthy donors (HD). In addition, we investigated clonal relations between CD21 low B cell subpopulations and plasmablasts in AS. Methods: RNA was isolated from sorted total B cells (CD19 +), two CD21 low B cell populations (CD21 low CD38 low CD27and CD21 low CD38 low CD27 +) and plasmablasts (CD19 + CD38 ++ CD27 +) from peripheral mononuclear cells of 10 AS patients fulfilling the mNY criteria (mean age 46 ± 9 years, 60% male, mean ASDAS 2.3 ± 0.8, all HLA-B27+), 10 sex-and age-matched HDs (mean age 48 ± 21 years, 60% male) and 10 age-matched pSS patients (mean age 46 ± 9 years, 20% male). Repertoire analysis of the B cell receptor heavy chain was performed using high throughput sequencing on the Illumina MiSeq Platform. Sequences were analyzed for degree of somatic hypermutation, usage of immunoglobulin heavy chain variable (IGHV) and joining (IGHJ) regions and clonal relationships. Results: IGHV sequences with identical heavy chain CDR3 regions were grouped together and were defined as a clone. Analysis of the IGHV mutation status in CD21 low B cells revealed that the majority of clones (71% SD ± 14.1) in the CD21 low CD38 low CD27subset from patients with AS consisted of clones with a low mutation rate (0-2 mutations in the IGHV region) (Figure 1b). On the contrary, most of the clones in the CD21 low CD38 low CD27 + (49% SD ± 12.5) and plasmablasts (59% SD ± 12.7) subsets were clones with a higher mutation load (>10 mutations in the IGHV region). A similar mutational pattern was seen in pSS patients and HDs. In AS, IGHV3 and IGHJ4 family genes were predominantly used (Figure 1c). However, we observed no differences in family gene usage among B cell subsets nor between groups. To investigate clonal relationships we performed a CDR3 amino acid network analysis on the top 100 most expanded clones per subset in AS patients and found that the CD21 low CD38 low CD27subset shared more clones with the CD21 low CD38 low CD27 + subset (median 3.0 (0.8-7.0 IQR), p< 0.05) compared to plasmablasts (median 0.0 (0-1.3 IQR). Conclusion: This study shows that the expanded circulating CD21 low CD-38 low CD27-B cell population in AS consists mainly of antigen-inexperienced cells. The presence of shared clones with their CD27 + counterpart and plasmablasts suggest that the three subsets are to some extent related. Hence, CD21 low CD38 low CD27-B cells may differentiate towards CD21 low CD38 low CD27 + B cells and plasmablasts. The relative roles of these CD21 low B cell subsets and plasmablasts in AS pathogenesis remain to be established. REFERENCES: [1] Wilbrink, R et al. (2021). B Cell Involvement in the Pathogenesis of Ankylosing Spondylitis. International journal of molecular sciences. [2] Wilbrink, R et al. (2021). CD27-CD38 low CD21 low B-Cells Are Increased in Axial Spondyloarthritis. Frontiers in immunology. Figure 1.

Research paper thumbnail of P663 Post-ustekinumab induction IL12, IL23, and ustekinumab levels are associated with clinical response in a multi-centre prospective cohort study of Crohn’s disease patients: results from the AURORA Study including ANZIBDC Cohort

Journal of Crohn's and Colitis

Background Ustekinumab (UST) is a monoclonal antibody targeting IL-12 and IL-23 through their sha... more Background Ustekinumab (UST) is a monoclonal antibody targeting IL-12 and IL-23 through their shared p40 subunit. This study aimed to determine the clinical outcomes after UST treatment in Crohn’s disease (CD) patients in a real-world setting, and to investigate the association of clinical outcomes with IL-12, IL-23 and UST levels. Methods A multi-centre prospective observational cohort study of UST for moderate to severe CD was conducted. Patients were recruited from 19 Australian centres between Sep 2019 and Apr 2022. Clinical assessments were performed at baseline study visit (SV) 1 and post-induction (SV2). Patients were assessed every 6 months during maintenance therapy to 18 months (SV4). Clinical response and remission rates were determined using PRO2 definitions (STRIDE II guidelines). Logistic regression analyses were performed to identify predictors of clinical response and remission. UST levels were measured post induction and interleukin levels including IL12p40 and IL-2...

Research paper thumbnail of S804 Pilot Study to Assess Pharmacokinetic and Pharmacodynamic Markers Following Enema-Dosing With Adalimumab in Patients With Active Ulcerative Colitis (UC)

American Journal of Gastroenterology

Research paper thumbnail of An inhibitor of Wnt protein production improves host control of Listeria monocytogenes

European Journal of Immunology, 2016

also previously shown that protein kinase C (PKC) βII is essential for DC differentiation and tha... more also previously shown that protein kinase C (PKC) βII is essential for DC differentiation and that tumor derived factors, particularly IL-6, inhibit DC differentiation by repressing the expression of PKCβII through a Stat3 dependent mechanism. However, the pathways activated downstream of PKCβII during DC differentiation have yet to be fully characterized. To study this, we used the K562 cell line, which differentiates into DCs with addition of PMA, a known chemical activator of conventional PKC isoenzymes. We have also shown previously that PMA specifically activates PKCβII in K562 cells. Addition of PMA to K562 cells showed the activation of the ERK1/2 and NFκB pathways, including both the canonical and non-canonical NFκB pathways. Chemical inhibition of either the ERK1/2 or NFκB pathway yielded immature DCs with a reduced capacity to stimulate T-cell proliferation when incubated with PMA. Inhibition of ERK1/2 also showed a change in levels of RelB, a NFκB transcription factor, with PMA treatment and during PMA induced DC differentiation. Inhibition of either the ERK1/2 or NFκB pathways showed an increase in Foxo3a levels, indicating a role for the ERK1/2 and NFκB pathways in Foxo3a regulation during differentiation into mature DCs. Taken together, these results show an integral role for both the ERK and NFκB pathways downstream of PKCβII activation during DC differentiation.

Research paper thumbnail of MUC1-mediated Macrophage Activation Promotes Colitis-associated Colorectal Cancer via Activating the Interleukin-6/ Signal Transducer and Activator of Transcription 3 Axis

Cellular and Molecular Gastroenterology and Hepatology

Research paper thumbnail of Invention of a Genetic Toolkit for Immunomodulatory Gut Bacteria to Expedite the Development of New Crohn's Disease Therapeutics

The public reporting burden for this collection of information is estimated to average 1 hour per... more The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188),

Research paper thumbnail of Tu1020 - Crohn's Colitis Care (CCcare) - Development and Testing of a Bespoke Cloud-Based Clinical Management System for Inflammatory Bowel Disease (IBD)

Gastroenterology, 2018

BACKGROUND: Fecal microbiota transplantation (FMT) can restore gut microbiota diversity and patho... more BACKGROUND: Fecal microbiota transplantation (FMT) can restore gut microbiota diversity and pathogen colonization resistance in patients with recurrent CDI. OBJECTIVE: The study compared improvement in fecal a and b diversity in subjects with recurrent CDI following FMT by lower GI administration (retention enema with frozen product) versus upper GI route (oral administration of lyophilized product in enteric coated capsules). METHODS: Microbiome analysis was performed on fecal samples from 39 subjects, 21 randomized to receive frozen FMT (100 g original fecal product) by retention enema and 18 to lyophilized FMT in enteric coated capsules (100 g or 200 g fecal product). Stool collected before FMT, 2, 30 and 90 days after FMT were analyzed for microbiome studies sequencing the variable 4 region of the 16S ribosomal-RNA gene on the Illumina MiSeq platform. RESULTS: Cure rates from subsequent bouts of CDI were similar in both treatment groups 18/21 (86%) for enema and 17/18 (94%) receiving capsules (P=0.61). Microbiota diversity, as measured by the inverse Simpson index, showed low baseline diversity in the 39 subjects with CDI pre-FMT, with minor improvement by day 2, after transplantation, and near complete recovery by day 30 in both treatment groups. Using UniFrac distances, we found that of recipients of frozen product by enema on Day 2 had more rapidly changed towards their FMT donors (median Day 2 UniFrac distance 0.51 vs 0.59 in lyophilized oral recipients, p=0.0003), indicating that a frozen enema was more effective at normalizing the microbiome at an early stage. Examining the major taxonomical subsets of intestinal bacteria, we found that while Clostridia were efficiently transferred by both treatment modalities, Bacteroidia and Verrucomicrobia were less efficiently transferred by lyophilized oral FMT. CONCLUSIONS: Both FMT products (lyophilized or frozen) were effective in curing CDI recurrences but differed in their ability to restore the full breadth of the intestinal microbiome. The findings raise the possibility that spore-forming organisms such as Clostridia may be a more important subpopulation for the efficacy of FMT in treating recurrent CDI. In previous studies using lyophilized product given to subjects with CDI by colonoscopy, we did not observe a reduction in Bacteroidia or Verrucomicrobia, suggesting that small bowel factors, digestive enzymes and bile salts may have influenced the microbiota associated with lyophilized FMT product given orally. Tu1020 CROHN'S COLITIS CARE (CCCARE)-DEVELOPMENT AND TESTING OF A BESPOKE CLOUD-BASED CLINICAL MANAGEMENT SYSTEM FOR INFLAMMATORY BOWEL DISEASE (IBD)

Research paper thumbnail of Sa1828 - Enteropathogens Detected on Stool Culture and Multiplex PCR are a Common Finding in Inflammatory Bowel Disease Patients

Research paper thumbnail of Crohn’s Colitis Care (CCCare): bespoke cloud-based clinical management software for inflammatory bowel disease

Scandinavian Journal of Gastroenterology, 2020

Abstract Background Adherence to evidence-based management is variable in inflammatory bowel dise... more Abstract Background Adherence to evidence-based management is variable in inflammatory bowel disease (IBD), which leads to worse patient outcomes and higher healthcare utilization. Solutions include electronic systems to enhance care, but these have often been limited by lack of clinician design input, poor usability, and low perceived value. A cloud-based IBD-specific clinical management software – ‘Crohn’s Colitis Care’ (CCCare) was developed by Australia and New Zealand Inflammatory Bowel Disease Consortium clinicians and software developers to improve this. Methods CCCare captures patient-reported disease activity and medical assessment, medication monitoring, cancer screening, preventative health, and facilitates communication with the IBD team and referring doctor. De-identified longitudinal data are stored separately in a clinical quality registry for research. CCCare was tested for feasibility and usability in routine clinical settings at two large Australian hospitals. Users’ experience was evaluated with System Usability Scale (SUS). Value to clinicians and patients was assessed by qualitative feedback. Security was assessed by penetration testing. Results Users (n = 13; doctors, nurses, patients) reported good usability and learnability (mean SUS score 75 (range 50–95), sub-scores were 77 (50–94) and 68 (38–100), respectively). Patients reported better communication with clinical team and greater ability to track disease. Clinicians highlighted structured management plans, medication adherence, and centralised data repository as positive features. Penetration testing was passed successfully. Conclusions Initial evaluation demonstrates CCCare is usable, secure, and valued in clinical use. It is designed to measure outcomes of clinical care, including efficacy, quality, cost, and complications for individuals, and to audit these at hospital and national level.

Research paper thumbnail of Practical management of inflammatory bowel disease patients during the COVID‐19 pandemic: expert commentary from the Gastroenterological Society of Australia Inflammatory Bowel Disease faculty

Internal Medicine Journal, 2020

The COVID‐19 pandemic, caused by the novel coronavirus SARS‐CoV‐2, has emerged as a public health... more The COVID‐19 pandemic, caused by the novel coronavirus SARS‐CoV‐2, has emerged as a public health emergency and challenged healthcare systems globally. In a minority of patients, SARS‐CoV‐2 manifests with a severe acute respiratory illness and currently there are insufficient data regarding the virulence of COVID‐19 in inflammatory bowel disease patients taking immunosuppressive therapy. This review aims to summarise the current literature and provide guidance on the management of inflammatory bowel disease (IBD) patients in the context of the COVID‐19 pandemic in the Australasian setting.

Research paper thumbnail of P328 Crohn’s colitis care (CCCare): development and testing of a bespoke cloud-based clinical management system for inflammatory bowel disease (IBD)

Journal of Crohn's and Colitis, 2018

Background: With improved therapy, patients with inflammatory bowel disease(IBD) often embark upo... more Background: With improved therapy, patients with inflammatory bowel disease(IBD) often embark upon overseas travel. Pre-travel risk management for infections, venous thromboembolism (VTE) and potential for flares might be appropriate. However, there are few data regarding these recommendations and heterogeneity in recommendations is likely related to different levels of immunosuppression, duration of flight and travel origin. Methods: Gastroenterologists from Australia (AUS) and Asia-Pacific (AP) region completed a web-based structured questionnaire evaluating travel topics such as pre-travel vaccination, VTE prophylaxis, and managing travellers' diarrhoea or IBD flares. Scenario-based responses on potential tuberculosis(TB) exposure in those with low-(azathioprine, vedolizumanb) vs. high-level (anti-tumour necrosis factor) immunosuppression were obtained. We hypothesised there were no differences between AUS and AP doctors' recommendations. Our primary endpoints were differences between AUS and AP respondents. Results: A total of 92 surveys were obtained (response rate 60%, AUS, n = 58, AP, n = 17, mean 12.9(±10.7) years of experience). Half of all respondents saw >6 IBD patients per week. More than 65% of respondents covered all travel-related topics (AUS vs. AP, p = ns) but significantly more AUS respondents discussed vaccinations than AP respondents (88% vs. 77%, p = 0.04, Table 1). Up to 65% of respondents recommended malaria prophylaxis, and advised against yellow fever (p = 0.17) and BCG vaccination (p = 0.29, Table 2). 71% of AUS respondents advised high-level immunosuppressed patients not to travel to TB-endemic area, compared with 12% of AP respondents (p < 0.01). Up to 88% of respondents disagreed with TB prophylaxis antibiotics (p = 0.89), stopping immunosuppressives (p = 0.37) prior to TB endemic countries, with AUS respondents trended to recommend pre-/post-travel CXR (p = 0.08) and not tuberculin skin test (p = 0.14). Interferon-Gamma Release Assay was preferred by AUS respondents (p < 0.01) (Table 3). Only 22% of respondents recommended anticoagulation for VTE prophylaxis. No predictors of VTE use were identified. Appropriate travellers' diarrhoea advice was provided by both groups. Conclusions: AUS physicians were more risk-averse compared with AP physicians regarding potential TB exposure. There were no differences in recommendations on VTE prophylaxis, vaccinations or management of infectious diarrhoea or IBD flares between the two regions. Travel-related consensus guidelines are likely, therefore, to be relevant for both regions.

Research paper thumbnail of Tu1302 INVESTIGATING THE ROLE OF BIOACTIVES PRODUCED BY GUT BACTERIA TO MODULATE IMMUNE RESPONSE IN IBD

Gastroenterology, 2020

Background: Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition of the gastroint... more Background: Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract. Although the pathogenesis of IBD is not fully understood, it is believed to result from the interaction between various genetic and environmental factors, including the microbiome, resulting in inappropriate gut inflammation. Under homeostatic conditions, the gut immune system exists in a tolerogenic state with the microbiota. However, microbial dysbiosis and an imbalance of pro-and anti-inflammatory cytokines in the gut characterise IBD and recently faecal microbiota transplantation studies have demonstrated that manipulation of the microbiome can induce remission. In this study, the ability of bioactives produced from single species of anaerobic gut bacteria cultured from healthy human faecal samples to modulate NF-kB activity was investigated, their biochemical properties were assessed and their ability to alleviate colitis was also investigated. Methods: The NF-kB suppressive effects of culture supernatants (CSs) from 23 different isolates were tested on colonic epithelial cell lines. Suppressive CSs were also tested on human-derived colonic organoids from IBD patients and healthy controls and IL-8 expression was measured. Furthermore, CS from AHG0001 strain was also tested in spontaneous colitis model Winnie in vivo. The supernatant was further characterised by extraction in multiple solvents and fractionated through reversedphase analytic HPLC column to test for suppressive fractions and further investigate their chemical characteristics. Results: LS174T and Caco-2 reporter cells stimulated with TNF a and IL-1b respectively, resulted in NF-kB activation. Of the 23 isolates screened, CS from five isolates significantly suppressed NF-kB activation. The selected CSs also suppressed IL-8 secretion in PBMCs and gut organoids from both UC and CD patients, as well as healthy controls, with notable individual variation. Rectal gavage of CS from AHG0001 also reduced disease activity, improved histologic inflammation and reduced the proinflammatory gene expression in Winnie mice. Furthermore, a potent small molecule (IC50=3nM) produced by AHG0001 was also identified through bioassay guided solvent extractions and filtrations, followed by UPLC-QTOF and comparative metabolomics. Conclusions: Our anaerobic culturing and NF-kB reporter assay system allows for the rapid identification of bacteria producing immunomodulatory bioactives, which could lead to the future development of novel therapeutics. Our in vivo and ex vivo testing utilising spontaneous colitis model and patient derived organoids demonstrates the potential of precision medicine-based approaches for bacterial based therapeutics.

Research paper thumbnail of Sa1913 CONSENSUS GUIDELINES FOR THE REGULATION, PRODUCTION AND USE OF FECAL MICROBIOTA TRANSPLANTATION IN CLINICAL PRACTICE

Gastroenterology, 2020

Background: Methane (CH 4) production has been associated with a number of clinical conditions bu... more Background: Methane (CH 4) production has been associated with a number of clinical conditions but remains poorly studied due to a reliance on breath CH 4 measurements for characterization of CH 4 and non-CH 4 producers. Therefore, we explored the relationship between the abundance of methanogenic archaea (methanogens) and CH 4 production in vitro in an effort to identify quantitative molecular thresholds that can be used to differentiate CH 4 and non-CH 4 producers. Methods: Fecal samples were collected to assess intestinal microbial composition and to evaluate concentrations of CH 4. Samples were processed within 2 hours of collection. Quantitative PCR (qPCR) was performed targeting the mcrA gene, which encodes the alpha subunit of methyl coenzyme M reductase (enzyme that catalyzes final step in methanogenesis). qPCR data was corrected for wet stool weight. Highthroughput DNA sequencing, targeting the V4 region of the 16S rRNA gene, was performed to determine relative abundance of Euryarchaeota. Up to 40g of sample was homogenized with phosphate-buffered saline in a blender pre-purged with nitrogen gas. Ten grams of this material was transferred to gas-tight septum jars, purged with nitrogen gas, and incubated at 37°C for 2 hours. After incubation, 2 mL gas samples were injected into a gas chromatograph with a flame ionization detector for CH 4 measures. Calibration gases were used as standards. Dry weight of the sample was calculated by loss on drying method after heating at 68°C for ‡24 hours. CH 4 measures were corrected to ppm/g dry weight of stool. Receiver operating characteristic analysis was used to generate detection thresholds. Results: Thirtythree samples from unique individuals were included in the analysis. Of these, ten were found to be CH 4 producers. Total mcrA gene copies correlated with CH 4 gas production (R=0.53; Figure 1). The detection threshold for CH 4 production was calculated to be 5.1x10 5 mcrA gene copies per gram feces. Methanobrevibacter was the most abundant methanogen group and its relative abundance provides a clear distinction between methane and nonmethane producers (Table 1). Its detection threshold for CH 4 production was calculated to be 0.089%. A positive trend was observed between the relative abundance of Methanobrevibacter (%) and CH 4 gas production values (R=0.45). A strong correlation (R=0.95) was observed between total mcrA gene copies (per g feces) and total relative abundance (%) of methanogens within Euryarchaeota. Conclusions: A threshold of 5.1x10 5 mcrA gene copies per gram feces or a Methanobrevibacter relative abundance of ‡0.089% are reliable biomarkers of intestinal CH 4 production capacity. Identification of these thresholds provides a means for molecular assessment of CH 4 production capacity and can potentially facilitate a wide range of clinical research without the need for cumbersome gas measurements. S-477 AGA Abstracts Total mcrA gene copies correlated with CH 4 gas production (R=0.53). The detection threshold for CH 4 production was calculated to be 5.1x10 5 mcrA gene copies per gram feces.