Marie-Benedicte Romond - Academia.edu (original) (raw)
Papers by Marie-Benedicte Romond
Microbiome Research Reports
Aim: The “gut-joint” axis is suspected to be involved in the pathophysiology of osteoarthritis (O... more Aim: The “gut-joint” axis is suspected to be involved in the pathophysiology of osteoarthritis (OA). The present study aims at investigating the potential of lipoproteins (Lpps) secreted by Bifidobacterium longum to alleviate OA progression in the rat. Methods: Experimental OA was induced in rats harbouring Schaedler Flora maintained in SPF conditions. Two weeks post-injection, 20 rats were randomized to water (n = 10) or 0.3 mg/L Lpps solution (n = 10). Weight and food intake were monitored for 6 weeks. At sacrifice, joints were scored using macroscopic and histological criteria. Serum LPS, Schaedler flora as well as selected intestinal bacteria were analyzed. Results: Lpps intake prevents OA progression. The protected rats showed a significant increase in lactobacilli along the intestine as well as in Mucispirillum schaedleri in the colon and a significant decrease in Parabacteroides goldsteini and Akkermansia in caecum and colon, respectively. There was no significant difference ...
Virulence, 2017
Introduction: Although known as cytolytic viruses, group B coxackieviruses (CVB) are able to esta... more Introduction: Although known as cytolytic viruses, group B coxackieviruses (CVB) are able to establish a persistent infection in vitro and in vivo. Viral persistence has been reported as a key mechanism in the pathogenesis of CVB-associated chronic diseases such as type 1 diabetes (T1D). The impact of CVB4 persistence on human pancreas ductal-like cells was investigated. Methods: A persistent CVB4 infection was established in ductal-like cells. PDX-1 expression, resistance to CVB4induced lysis and CAR expression were evaluated. The profile of cellular microRNAs (miRNAs) was investigated through miRNA-sequencing. Viral phenotypic changes were examined, and genomic modifications were assessed by sequencing of the viral genome. Results: The CVB4 persistence in ductal-like cells was productive, with continuous release of infectious particles. Persistently infected cells displayed a resistance to CVB4-induced lysis upon superinfection and expression of PDX-1 and CAR was decreased. These changes were maintained even after virus clearance. The patterns of cellular miRNA expression in mock-infected and in CVB4-persistently infected ductal-like cells were clearly different. The persistent infection-derived virus (PIDV) was still able to induce cytopathic effect but its plaques were smaller than the parental virus. Several mutations appeared in various PIDV genome regions, but amino acid substitutions did not affect the predicted site of interaction with CAR. Conclusion: Cellular and viral changes occur during persistent infection of human pancreas ductal-like cells with CVB4. The persistence of cellular changes even after virus clearance supports the hypothesis of a long-lasting impact of persistent CVB infection on the cells.
Journal of Medical Virology, 2013
The role of enteroviruses in type 1 diabetes has long been suspected. A lower risk of type 1 diab... more The role of enteroviruses in type 1 diabetes has long been suspected. A lower risk of type 1 diabetes is associated with breastfeeding, which could be due to a protective effect against enteroviruses. The neutralizing activity of breast milk against CVB4, a representative of enteroviruses was investigated in this study in vitro. Breast milk was cytotoxic to Hep-2 cells up to a dilution of 1/32, whereas the aqueous fraction obtained after centrifugation was not cytotoxic; although it inhibited the cytopathic effect of CVB4 on Hep-2 cell monolayers. The anti-CVB4 neutralizing activity of aqueous fractions of breast milk from 49 donors living in Northern France and 15 donors living in Congo, where enteroviral infections are more prevalent, were determined. The levels of colostrum activity expressed as titre ranged from <2 to 32 in 36% of the donors from France whereas they were >128 in every donor from Congo. Pasteurized colostrum had a lower anti-CVB4 activity compared to fresh samples (P < 0.0001, n ¼ 49). The treatment of colostrum samples with jacalin-coated beads that bind specifically to human IgA, showed that IgA plays a role in anti-CVB4 activity. There was no correlation between the neutralizing activities of breast milk and serum (P ¼ 0.37, n ¼ 25). The current study showed that the variations in anti-CVB4 activity in breast milk can be attributed to environmental and living conditions. Whether a low protective activity of breast milk against enteroviruses expose newborns to a higher risk of type 1 diabetes deserves further investigation.
Archives de Pédiatrie, 2008
Introduction. d-lactic acidosis is a rare and severe complication of short bowel syndrome in chil... more Introduction. d-lactic acidosis is a rare and severe complication of short bowel syndrome in children that may result from important ileal bacterial overgrowth by lactobacilli. Intestinal flora (Lactobacilli) is responsible for the production of d-lactic acid after fermentation of food carbohydrates. Observation. We report on the case of a 6-year-old child with a short bowel syndrome treated with both home enteral and parenteral nutrition. The patient suddenly presented with acute neurological symptoms including dysarthria and desorientation. Biological analysis revealed metabolic acidosis, increased plasma d-lactic acid assessed by organic acid chromatography analysis and a very important increase in expired hydrogen during glucose breath test. Lactobacillus fermentum (known to produce d and L isomers of lactic acid) was isolated in the gastric liquid and rectal swabs. Clinical and biological evolution was rapidly favourable after treatment with intravenous sodium bicarbonate, antibiotic therapy and interruption of enteral nutrition. Conclusion. d-lactic acidosis should be suspected when neurological symptoms occur in a child with short bowel syndrome. They can be prevented by treating intestinal bacterial overgrowth.
The Journal of Nutritional Biochemistry, 2018
Impaired intestinal barrier function occurs before type 1 diabetes (T1D) onset with a possible co... more Impaired intestinal barrier function occurs before type 1 diabetes (T1D) onset with a possible contribution of microbial translocation. Breastfeeding is associated with enhanced mucosal intestinal integrity and T1D protection. Our aim was to study the potential of human milk (HM) to prevent diabetes onset and modulate the translocation of gut bacteria susceptible to breastfeeding or associated to diabetes onset. We show that HM intake can prevent T1D in nonobese diabetic mice independently of bifidobacteria colonization. Prior to diabetes onset, HM mice harbored splenic bacterial counts and plasma lipopolysaccharides level similar to control mice but exhibited a reduced expansion of Anaerotruncus sp. in pancreas and Lactobacillus johnsonii and Barnesiella in Peyer's patches (PP). Surprisingly, pancreas and PP bacterial expansion did not correlate with their own gut localization but with ileal Escherichia coli and cecal HM-susceptible bacteria (the promoted L. murinus and Bacteroides vulgatus, and the repressed B. fragilis and E. coli), respectively. Besides, higher colonic B. vulgatus counts induced by HM intake were associated with low islet infiltration and pancreatic E. coli expansion. On another hand, splenic dendritic cells (DCs) were identified as negative covariate of PP Barnesiella, suggesting a possible HM contribution to preserving splenic DCs through the reduction of Barnesiella translocation. Fecal B. vulgatus also negatively correlated with PP Barnesiella expansion, indicating that the mouse coprophagic behavior likely added to HM effect. Our findings provide evidence that HM has a multilevel impact and cooperates with some gut bacteria for controlling bacterial translocation at the earliest stage of insulitis.
Médecine et Maladies Infectieuses, 1990
ABSTRACT Nous avons utilisé des souris C3H porteuses de la microflore intestinale de hamster pour... more ABSTRACT Nous avons utilisé des souris C3H porteuses de la microflore intestinale de hamster pour étudier les mécanismes de la résistance à la colonisation par C. difficile et avons isolé trois souches bactériennes anaérobies responsables de cette résistance. La reconstitution d'une microflore active minimale chez la souris axénique ne se produit que si ces trois souches sont inoculées dans un ordre déterminé. Il était intéressant d'étudier les activités enzymatiques de ces souches envers la mucine considérée comme un substrat présent dans le tube digestif, dont la structure peut être modifiée sous l'action protéolytique et/ou osidasique des bactéries. Ces activités enzymatiques ont été étudiées in vitro, en présence de mucine, et in vivo, dans les fécès de souris monoxéniques, dixéniques et trixéniques. L'acitvité enzymatique de la première souche colonisante (C. indolis) ne modifie que partiellement la structure de la mucine; par conséquent, l'action conjointe des différentes souches est nécessaire pour obtenir une dégradation complète de la mucine. La seconde souche (C. cocleatum) est la plus active. Ces résultats ont été confirmés par électrophorèse sur agarose et gel de polyacrylamide des extraits de protéines fécales de souris monoxéniques, dixéniques et trixéniques. Les modifications de la mucine induites par les activités enzymatiques responsables d'une résistance de colonisation envers C. difficile pourraient jouer un rôle dans le mécanisme d'action de la microflore.
Anaerobe, 1997
Background: Recently, exploring novel dietary nondigestible carbohydrates, which are able to infl... more Background: Recently, exploring novel dietary nondigestible carbohydrates, which are able to influence the gut flora, has drawn much attention. The objective of this study was to find out the effective dose of levan, as a prebiotic, in rats in order to further apply in food industry. Methods: Levan at various doses (2-10%) was orally administered to male Wistar Albino rats once a day for 90 days. At the end of experiment, fecal and blood samples were collected to measure gut bacteria population and to carry out serum biochemical assay. The rats were sacrificed, and the colon tissues were stained with H&E and analyzed by histopathology. Results: Of note, levan effectively controlled body weight gain in the rats. Serum biochemical analysis revealed that 5% levan significantly diminished the serum level of total cholesterol, LDL, and glucose as well. More notably, 5% levan intake significantly increased the abundance of bifidobacteria population, highlighting its bifidogenic effect. Furthermore, our histopathological result revealed that daily intake of levan was associated with a higher degree of thickness of the mucosa layer compared to the rats in control group. Moreover, these findings manifested no colon inflammation in the rats fed with levan. Conclusion: The findings of this study provide the fundamental data to use levan at a definite dose for further development in functional foods.
Anaerobe, 2011
Short bowel syndrome (SBS) occurs in patients fed total parenteral nutrition (TPN) after massive ... more Short bowel syndrome (SBS) occurs in patients fed total parenteral nutrition (TPN) after massive intestinal resection. TPN weaning is often associated with occlusion or sepsis. In the present study the intestinal biotope was investigated in young patients (n ¼ 14) with massive intestinal resection and recurrent symptoms of sepsis or occlusion during enteral food introduction. They were treated by aminosides for a long term period. Ileal effluents were collected for enumerating bacteria. In some case, blood and rectal specimen were also collected. A few patients developed bacterial overgrowth (1), occlusion (1), sepsis (4), osteoarthritis (1) or pneumonia (1) during the survey. A drastic drop of bifidobacteria that was not prevented by human milk feeding was observed prior occlusion or respiratory infection. Detection of clostridial vegetative forms preceded sepsis and decrease in clostridia parallelled recovery. In conclusion, onset of symptoms was related with extreme imbalance of the ileal flora. Supplementation with bifidobacterial compounds that were well tolerated in two patients could be of interest in children with recurrent symptoms.
Pediatric Surgery International, 1996
Intestinal ischemia was created after a limited laparotomy by ligation of the terminal mesenteric... more Intestinal ischemia was created after a limited laparotomy by ligation of the terminal mesenteric vessels in the last 10 cm of distal ileum in 2-day-old piglets. Five groups (each n = 15) were studied: 1 (unoperated control group, killed on day 4), 2 (sham control with laparotomy, killed on day 4), 3 (ischemia, killed on day 4), 4 (ischemia, killed on day 9), and 5 (unoperated control on day 9, not killed). All animals in groups 1, 2 and 5 survived. Two animals in group 3 and 1 in group 4 died (peritonitis and distal ileal perforation). In animals killed on day 9, less weight gain was observed in group 4 compared to the unoperated controls. Macroscopically, no alteration was found at laparotomy in the animals in group 1, whereas in group 2, 1 animal showed begining peritonitis and another some degree of peritoneal adhesions in group 3, 1 piglet had an intestinal perforation and 4 had intestinal distension above the ischemic loop. In group 4, 7 animals had dilatation of the upper loops, 4 a complete stricture, and 3 peritonitis with complete necrosis of the distal ileum. Microscopic examination revealed severe lesions of the ischemic area in groups 3 and 4 and mild lesions of the upper loop. The kidney was contaminated by translocation of gram-positive cocci in 36% of cases in group 2. Germ carriage for staphylococci was estimated at 80% in the terminal ileum of animals in group 3 versus 8.3% in group 2. In groups 3 and 4, the translocation rate was 30% in the kidney and 40% in the liver. Low disaccharidase activities were found in ischemic areas in groups 3 and 4, with no difference in activity in the upper loops.
Pediatric Surgery International, 2001
The eects of mesenteric ischemia on ileal colonization, intestinal integrity, and bacterial trans... more The eects of mesenteric ischemia on ileal colonization, intestinal integrity, and bacterial translocation (BT) in newborn piglets were investigated in 36-2-day-old Pietrain piglets. Group I, controls were not operated upon; group II underwent a sham laparotomy; and group III underwent ligation of the mesenteric vessels in the distal ileum. After 3 days, the kidneys, spleens, livers, and ileal segments were harvested for microbial and histologic analyses. Two piglets in the ischemic group died; microscopic examination showed severe histologic lesions of the ischemic area. Escherichia coli counts were increased in the ischemic segment compared to the upper loop (P < 0.05). Ischemia favoured staphylococcal colonization, whereas in the sham group a drastic reduction of these organisms was observed (P < 0.005). BT to the kidneys, spleen, and liver occurred normally in the control group. Ischemia signi®cantly increased the total micro¯ora in the spleen and liver (P < 0.05) and furthered dissemination of Clostridium perfringens in the kidneys (P < 0.05); 50% of ischemic animals had proteolytic clostridia in this organ (P < 0.05). Moreover, the incidence of E. coli in the kidneys, spleen, and liver was signi®cantly higher in the sham and ischemic groups than in the controls (P < 0.05). Ileal ischemia thus induced signi®cant histologic lesions, and surgery rather than gut micro¯ora controls translocation.
Journal of Applied Microbiology, 2001
To investigate the effects of whey retentate from Bi®dobacteria fermented milk. Methods and Resul... more To investigate the effects of whey retentate from Bi®dobacteria fermented milk. Methods and Results: The simulator of the human intestinal microbial ecosystem (SHIME) was used. The composition of the microbiota and its metabolic activities were analysed. Changes in the microbial composition became apparent within 15 days of the treatment in the vessels representing the ileum and the large intestine. The whey retentate favoured the growth of endogenous bi®dobacteria and induced a decrease in Bacteroides fragilis and in sul®phoreducing clostridia, especially Clostridium perfringens. After the administration was stopped, these populations tended to revert to their original levels, except for the streptococci and the staphylococci populations. The treatment also led to an increase in acetic acid, CH 4 and CO 2 production, suggesting overgrowth of some anaerobic bacteria. Ammonium, generally considered as undesirable, declined. Conclusions: The whey retentate clearly altered the microbial community in the SHIME. Signi®cance and Impact of the Study: Whey retentate appears to exert a bene®cial effect on the in vitro gastrointestinal system; these ®ndings warrant con®rmation by in vivo studies.
Current Microbiology, 1990
A study on strains received as Pseudomonas alcaligenes was performed by the DNA-DNA hybridization... more A study on strains received as Pseudomonas alcaligenes was performed by the DNA-DNA hybridization procedure. Results on strains phenotypically distinct (subcluster A~; Gavini et al., Int J Syst Bacteriol [1989] 39:135-144) from P. alcaligenes strains (subcluster B~) pointed out that (a) these strains belonged to Comamonas testosteroni species (DNA-DNA homology 75%-98%) and (b) the two species could be differentiated by biochemical tests other than type of flagellation or poly-/3-hydroxybutyrate deposits.
Comparative Immunology, Microbiology and Infectious Diseases, 1992
Studies were undertaken to determine the regulation of the bacterial intestinal implantation in 1... more Studies were undertaken to determine the regulation of the bacterial intestinal implantation in 19 newborns delivered by caesarian section. Correlation was made with the infant feeding mode. The effect of human milk seemed to be the result of B. bifidum proliferation, in contrast to artificial alimentation that seemed to favour C. perfringens implantation. The question was raised by us as to whether this opposition was only related to alimentation. In fact, B. bifidum itself also had an effect as demonstrated by the lower mean counts of C. perfringens in bottle-fed infants carrying the bifidobacterial flora (P = 0.05). None of the other faecal bacteria investigated in this study led to the same decrease.
Journal of Pediatric Gastroenterology and Nutrition, 2004
Archives De Pediatrie, May 1, 2000
Les propriMs anti-infectieuses de l'allaitement maternel reposent non seulement sur la prksence d... more Les propriMs anti-infectieuses de l'allaitement maternel reposent non seulement sur la prksence de facteurs asp& cifiques (gynolactose, mucines) et spkifiques de l'immunitk (immunoglobulines, cellules) mais encore sur la capacitk & stimuler une sCrie de rkponses chew le nour-r&on. Ainsi, la tlore intestinale du nourrisson allait au sein est majoritairement composke de Rifidohucteriunz. qui s'implante 4-S jours aprks la naissance par voie basse (trrbleuu I). Or, ces germes anakrobies de morphologie en Y se distinguent des autres bactkries h Gram positif du biotope intestinal par des propriMs immunostimulantes spkifiques. Chez l'animal. elles induisent une maturation de I'immunitt! cellulaire qui rCgule la translocation d'E.sc/zerichrr
Microbial Ecology in Health & Disease, 1989
The buffering capacity of a milk diet is known to be involved in the control of a newborn's bifid... more The buffering capacity of a milk diet is known to be involved in the control of a newborn's bifidobacterial flora. Other factors could modulate the bifidobacterial flora e.g. bifidus factors present in human milk, which are growth-promoting for Bi3dobacterium bi$durn. The aim of this study was to investigate in gnotobiotic mice the effects of human milk bifidus factors upon colonisation by bifidobacteria according to the dietary buffering capacity. A high buffering capacity diet encouraged the implantation of higher numbers of bifidobacteria in monoxenic mice than a low buffering capacity one. However, supplementary feeding with human milk oligosaccharides (gynolactose) did not support the proliferation of B. bijdum, although the gynolactose bifidus factors were not destroyed during digestion. Furthermore the addition of gynolactose to a high buffering capacity diet led to the breakdown of some of the intestinal glycoproteins detected in the bifidogenic extract of stools from germfree mice. In addition, although the human milk oligosaccharides stimulated the excretion of intestinal bifidus factors when supplementing a low buffering capacity diet, they failed to do so on a high buffering capacity diet. These results suggest that the ability of human milk oligosaccharides to encourage the proliferation of B. bijidum depends upon their capacity to stimulate intestinal bifidus factors. This capacity seemed to be related to the buffering capacity of the diet.
Journal of Pediatric Gastroenterology and Nutrition, 2004
FEMS Microbiology Letters, 1998
Resistance to the combination of amoxicillin and clavulanic acid in some Bacteroides fragilis str... more Resistance to the combination of amoxicillin and clavulanic acid in some Bacteroides fragilis strains may be associated with a lack of porin proteins. Comparison of outer membrane protein profiles from one resistant strain (B. fragilis CFPL 358) and two susceptible strains of B. fiagilis (ATCC 25285 and CFPL 92125) showed that a few proteins were missing in the resistant strain, especially a 45-kDa protein. To determine whether this protein was a porin-like protein, we attempted to isolate it from the two susceptible strains by using gel filtration (Sephacryl S-200, Superose 6) and ion exchange chromatographies (DEAE Trisacryl, DEAE Sepharose Fast Flow). Elution from DEAE resins was poor compared to the 60-67-kDa region, which suggested that the 45-kDa protein exhibited stronger cationic forms. The use of sodium dodecyl sulfate during elution improved the recovery of the 45-kDa protein, showing that detergent modified its conformation and its ionic bounds with the chromatographic matrices but it was not sufficient for good purification. Superose 6 gel filtration also failed to separate this protein from the 60-67-kDa region. The only method resulting in the positive recovery of a purified 45-kDa band from both susceptible B. jiragilis strains was electroelution from SDS-PAGE. The swelling assay showed that the 45-kDa protein was a porin-like protein. From this study, we concluded that the 45-kDa protein from B. fragilis was a porin-like protein which might be involved in the antibiotic resistance of a strain in which this protein was missing.
Journal of Dairy Science, 2002
Cell-free whey obtained from milk fermented with Bifidobacterium breve C50 (Bb C50) has been show... more Cell-free whey obtained from milk fermented with Bifidobacterium breve C50 (Bb C50) has been shown to modify the intestinal flora in humans and mice. Previous work showed that no antibiotic-like or barrier effect due to overgrowing bifidobacteria was implied in the microbial modifications. The present study was focused on characterizing the compounds and mechanisms involved. Protein, sugar, and enzymatic profiles of Bb C50 whey were therefore determined and compared to those of a whey unable to modify the intestinal flora of humans and mice. No remarkable difference was noted except for a higher lactosidase activity in Bb C50 whey. Various physical treatments were then applied to fractions of Bb C50 whey. Activity was assessed in C3H mice by analyzing changes in the intestinal flora balance throughout a 15-d administration of each treated whey. Heating at 80°C and aerobic storage for 2 wk completely abolished Bb C50 whey activities. In contrast, the addition of a reducing agent (cysteine hydrochloride), either at the beginning of a 15-d aerobic storage or prior to administration, as well as preserved these activities. Susceptibility to heating and oxidation suggested that an enzyme might play a role in the induced microbial changes. Since the Bb C50 lactosidase was partly inactivated by the oxidative treatment, it could support the in vivo activity. The enzyme might reach the intestinal lumen and partly degrade substrates, such as mucins, usually used by the intestinal flora. The released molecules might then favor the development of a new microbial balance.
Microbiome Research Reports
Aim: The “gut-joint” axis is suspected to be involved in the pathophysiology of osteoarthritis (O... more Aim: The “gut-joint” axis is suspected to be involved in the pathophysiology of osteoarthritis (OA). The present study aims at investigating the potential of lipoproteins (Lpps) secreted by Bifidobacterium longum to alleviate OA progression in the rat. Methods: Experimental OA was induced in rats harbouring Schaedler Flora maintained in SPF conditions. Two weeks post-injection, 20 rats were randomized to water (n = 10) or 0.3 mg/L Lpps solution (n = 10). Weight and food intake were monitored for 6 weeks. At sacrifice, joints were scored using macroscopic and histological criteria. Serum LPS, Schaedler flora as well as selected intestinal bacteria were analyzed. Results: Lpps intake prevents OA progression. The protected rats showed a significant increase in lactobacilli along the intestine as well as in Mucispirillum schaedleri in the colon and a significant decrease in Parabacteroides goldsteini and Akkermansia in caecum and colon, respectively. There was no significant difference ...
Virulence, 2017
Introduction: Although known as cytolytic viruses, group B coxackieviruses (CVB) are able to esta... more Introduction: Although known as cytolytic viruses, group B coxackieviruses (CVB) are able to establish a persistent infection in vitro and in vivo. Viral persistence has been reported as a key mechanism in the pathogenesis of CVB-associated chronic diseases such as type 1 diabetes (T1D). The impact of CVB4 persistence on human pancreas ductal-like cells was investigated. Methods: A persistent CVB4 infection was established in ductal-like cells. PDX-1 expression, resistance to CVB4induced lysis and CAR expression were evaluated. The profile of cellular microRNAs (miRNAs) was investigated through miRNA-sequencing. Viral phenotypic changes were examined, and genomic modifications were assessed by sequencing of the viral genome. Results: The CVB4 persistence in ductal-like cells was productive, with continuous release of infectious particles. Persistently infected cells displayed a resistance to CVB4-induced lysis upon superinfection and expression of PDX-1 and CAR was decreased. These changes were maintained even after virus clearance. The patterns of cellular miRNA expression in mock-infected and in CVB4-persistently infected ductal-like cells were clearly different. The persistent infection-derived virus (PIDV) was still able to induce cytopathic effect but its plaques were smaller than the parental virus. Several mutations appeared in various PIDV genome regions, but amino acid substitutions did not affect the predicted site of interaction with CAR. Conclusion: Cellular and viral changes occur during persistent infection of human pancreas ductal-like cells with CVB4. The persistence of cellular changes even after virus clearance supports the hypothesis of a long-lasting impact of persistent CVB infection on the cells.
Journal of Medical Virology, 2013
The role of enteroviruses in type 1 diabetes has long been suspected. A lower risk of type 1 diab... more The role of enteroviruses in type 1 diabetes has long been suspected. A lower risk of type 1 diabetes is associated with breastfeeding, which could be due to a protective effect against enteroviruses. The neutralizing activity of breast milk against CVB4, a representative of enteroviruses was investigated in this study in vitro. Breast milk was cytotoxic to Hep-2 cells up to a dilution of 1/32, whereas the aqueous fraction obtained after centrifugation was not cytotoxic; although it inhibited the cytopathic effect of CVB4 on Hep-2 cell monolayers. The anti-CVB4 neutralizing activity of aqueous fractions of breast milk from 49 donors living in Northern France and 15 donors living in Congo, where enteroviral infections are more prevalent, were determined. The levels of colostrum activity expressed as titre ranged from <2 to 32 in 36% of the donors from France whereas they were >128 in every donor from Congo. Pasteurized colostrum had a lower anti-CVB4 activity compared to fresh samples (P < 0.0001, n ¼ 49). The treatment of colostrum samples with jacalin-coated beads that bind specifically to human IgA, showed that IgA plays a role in anti-CVB4 activity. There was no correlation between the neutralizing activities of breast milk and serum (P ¼ 0.37, n ¼ 25). The current study showed that the variations in anti-CVB4 activity in breast milk can be attributed to environmental and living conditions. Whether a low protective activity of breast milk against enteroviruses expose newborns to a higher risk of type 1 diabetes deserves further investigation.
Archives de Pédiatrie, 2008
Introduction. d-lactic acidosis is a rare and severe complication of short bowel syndrome in chil... more Introduction. d-lactic acidosis is a rare and severe complication of short bowel syndrome in children that may result from important ileal bacterial overgrowth by lactobacilli. Intestinal flora (Lactobacilli) is responsible for the production of d-lactic acid after fermentation of food carbohydrates. Observation. We report on the case of a 6-year-old child with a short bowel syndrome treated with both home enteral and parenteral nutrition. The patient suddenly presented with acute neurological symptoms including dysarthria and desorientation. Biological analysis revealed metabolic acidosis, increased plasma d-lactic acid assessed by organic acid chromatography analysis and a very important increase in expired hydrogen during glucose breath test. Lactobacillus fermentum (known to produce d and L isomers of lactic acid) was isolated in the gastric liquid and rectal swabs. Clinical and biological evolution was rapidly favourable after treatment with intravenous sodium bicarbonate, antibiotic therapy and interruption of enteral nutrition. Conclusion. d-lactic acidosis should be suspected when neurological symptoms occur in a child with short bowel syndrome. They can be prevented by treating intestinal bacterial overgrowth.
The Journal of Nutritional Biochemistry, 2018
Impaired intestinal barrier function occurs before type 1 diabetes (T1D) onset with a possible co... more Impaired intestinal barrier function occurs before type 1 diabetes (T1D) onset with a possible contribution of microbial translocation. Breastfeeding is associated with enhanced mucosal intestinal integrity and T1D protection. Our aim was to study the potential of human milk (HM) to prevent diabetes onset and modulate the translocation of gut bacteria susceptible to breastfeeding or associated to diabetes onset. We show that HM intake can prevent T1D in nonobese diabetic mice independently of bifidobacteria colonization. Prior to diabetes onset, HM mice harbored splenic bacterial counts and plasma lipopolysaccharides level similar to control mice but exhibited a reduced expansion of Anaerotruncus sp. in pancreas and Lactobacillus johnsonii and Barnesiella in Peyer's patches (PP). Surprisingly, pancreas and PP bacterial expansion did not correlate with their own gut localization but with ileal Escherichia coli and cecal HM-susceptible bacteria (the promoted L. murinus and Bacteroides vulgatus, and the repressed B. fragilis and E. coli), respectively. Besides, higher colonic B. vulgatus counts induced by HM intake were associated with low islet infiltration and pancreatic E. coli expansion. On another hand, splenic dendritic cells (DCs) were identified as negative covariate of PP Barnesiella, suggesting a possible HM contribution to preserving splenic DCs through the reduction of Barnesiella translocation. Fecal B. vulgatus also negatively correlated with PP Barnesiella expansion, indicating that the mouse coprophagic behavior likely added to HM effect. Our findings provide evidence that HM has a multilevel impact and cooperates with some gut bacteria for controlling bacterial translocation at the earliest stage of insulitis.
Médecine et Maladies Infectieuses, 1990
ABSTRACT Nous avons utilisé des souris C3H porteuses de la microflore intestinale de hamster pour... more ABSTRACT Nous avons utilisé des souris C3H porteuses de la microflore intestinale de hamster pour étudier les mécanismes de la résistance à la colonisation par C. difficile et avons isolé trois souches bactériennes anaérobies responsables de cette résistance. La reconstitution d'une microflore active minimale chez la souris axénique ne se produit que si ces trois souches sont inoculées dans un ordre déterminé. Il était intéressant d'étudier les activités enzymatiques de ces souches envers la mucine considérée comme un substrat présent dans le tube digestif, dont la structure peut être modifiée sous l'action protéolytique et/ou osidasique des bactéries. Ces activités enzymatiques ont été étudiées in vitro, en présence de mucine, et in vivo, dans les fécès de souris monoxéniques, dixéniques et trixéniques. L'acitvité enzymatique de la première souche colonisante (C. indolis) ne modifie que partiellement la structure de la mucine; par conséquent, l'action conjointe des différentes souches est nécessaire pour obtenir une dégradation complète de la mucine. La seconde souche (C. cocleatum) est la plus active. Ces résultats ont été confirmés par électrophorèse sur agarose et gel de polyacrylamide des extraits de protéines fécales de souris monoxéniques, dixéniques et trixéniques. Les modifications de la mucine induites par les activités enzymatiques responsables d'une résistance de colonisation envers C. difficile pourraient jouer un rôle dans le mécanisme d'action de la microflore.
Anaerobe, 1997
Background: Recently, exploring novel dietary nondigestible carbohydrates, which are able to infl... more Background: Recently, exploring novel dietary nondigestible carbohydrates, which are able to influence the gut flora, has drawn much attention. The objective of this study was to find out the effective dose of levan, as a prebiotic, in rats in order to further apply in food industry. Methods: Levan at various doses (2-10%) was orally administered to male Wistar Albino rats once a day for 90 days. At the end of experiment, fecal and blood samples were collected to measure gut bacteria population and to carry out serum biochemical assay. The rats were sacrificed, and the colon tissues were stained with H&E and analyzed by histopathology. Results: Of note, levan effectively controlled body weight gain in the rats. Serum biochemical analysis revealed that 5% levan significantly diminished the serum level of total cholesterol, LDL, and glucose as well. More notably, 5% levan intake significantly increased the abundance of bifidobacteria population, highlighting its bifidogenic effect. Furthermore, our histopathological result revealed that daily intake of levan was associated with a higher degree of thickness of the mucosa layer compared to the rats in control group. Moreover, these findings manifested no colon inflammation in the rats fed with levan. Conclusion: The findings of this study provide the fundamental data to use levan at a definite dose for further development in functional foods.
Anaerobe, 2011
Short bowel syndrome (SBS) occurs in patients fed total parenteral nutrition (TPN) after massive ... more Short bowel syndrome (SBS) occurs in patients fed total parenteral nutrition (TPN) after massive intestinal resection. TPN weaning is often associated with occlusion or sepsis. In the present study the intestinal biotope was investigated in young patients (n ¼ 14) with massive intestinal resection and recurrent symptoms of sepsis or occlusion during enteral food introduction. They were treated by aminosides for a long term period. Ileal effluents were collected for enumerating bacteria. In some case, blood and rectal specimen were also collected. A few patients developed bacterial overgrowth (1), occlusion (1), sepsis (4), osteoarthritis (1) or pneumonia (1) during the survey. A drastic drop of bifidobacteria that was not prevented by human milk feeding was observed prior occlusion or respiratory infection. Detection of clostridial vegetative forms preceded sepsis and decrease in clostridia parallelled recovery. In conclusion, onset of symptoms was related with extreme imbalance of the ileal flora. Supplementation with bifidobacterial compounds that were well tolerated in two patients could be of interest in children with recurrent symptoms.
Pediatric Surgery International, 1996
Intestinal ischemia was created after a limited laparotomy by ligation of the terminal mesenteric... more Intestinal ischemia was created after a limited laparotomy by ligation of the terminal mesenteric vessels in the last 10 cm of distal ileum in 2-day-old piglets. Five groups (each n = 15) were studied: 1 (unoperated control group, killed on day 4), 2 (sham control with laparotomy, killed on day 4), 3 (ischemia, killed on day 4), 4 (ischemia, killed on day 9), and 5 (unoperated control on day 9, not killed). All animals in groups 1, 2 and 5 survived. Two animals in group 3 and 1 in group 4 died (peritonitis and distal ileal perforation). In animals killed on day 9, less weight gain was observed in group 4 compared to the unoperated controls. Macroscopically, no alteration was found at laparotomy in the animals in group 1, whereas in group 2, 1 animal showed begining peritonitis and another some degree of peritoneal adhesions in group 3, 1 piglet had an intestinal perforation and 4 had intestinal distension above the ischemic loop. In group 4, 7 animals had dilatation of the upper loops, 4 a complete stricture, and 3 peritonitis with complete necrosis of the distal ileum. Microscopic examination revealed severe lesions of the ischemic area in groups 3 and 4 and mild lesions of the upper loop. The kidney was contaminated by translocation of gram-positive cocci in 36% of cases in group 2. Germ carriage for staphylococci was estimated at 80% in the terminal ileum of animals in group 3 versus 8.3% in group 2. In groups 3 and 4, the translocation rate was 30% in the kidney and 40% in the liver. Low disaccharidase activities were found in ischemic areas in groups 3 and 4, with no difference in activity in the upper loops.
Pediatric Surgery International, 2001
The eects of mesenteric ischemia on ileal colonization, intestinal integrity, and bacterial trans... more The eects of mesenteric ischemia on ileal colonization, intestinal integrity, and bacterial translocation (BT) in newborn piglets were investigated in 36-2-day-old Pietrain piglets. Group I, controls were not operated upon; group II underwent a sham laparotomy; and group III underwent ligation of the mesenteric vessels in the distal ileum. After 3 days, the kidneys, spleens, livers, and ileal segments were harvested for microbial and histologic analyses. Two piglets in the ischemic group died; microscopic examination showed severe histologic lesions of the ischemic area. Escherichia coli counts were increased in the ischemic segment compared to the upper loop (P < 0.05). Ischemia favoured staphylococcal colonization, whereas in the sham group a drastic reduction of these organisms was observed (P < 0.005). BT to the kidneys, spleen, and liver occurred normally in the control group. Ischemia signi®cantly increased the total micro¯ora in the spleen and liver (P < 0.05) and furthered dissemination of Clostridium perfringens in the kidneys (P < 0.05); 50% of ischemic animals had proteolytic clostridia in this organ (P < 0.05). Moreover, the incidence of E. coli in the kidneys, spleen, and liver was signi®cantly higher in the sham and ischemic groups than in the controls (P < 0.05). Ileal ischemia thus induced signi®cant histologic lesions, and surgery rather than gut micro¯ora controls translocation.
Journal of Applied Microbiology, 2001
To investigate the effects of whey retentate from Bi®dobacteria fermented milk. Methods and Resul... more To investigate the effects of whey retentate from Bi®dobacteria fermented milk. Methods and Results: The simulator of the human intestinal microbial ecosystem (SHIME) was used. The composition of the microbiota and its metabolic activities were analysed. Changes in the microbial composition became apparent within 15 days of the treatment in the vessels representing the ileum and the large intestine. The whey retentate favoured the growth of endogenous bi®dobacteria and induced a decrease in Bacteroides fragilis and in sul®phoreducing clostridia, especially Clostridium perfringens. After the administration was stopped, these populations tended to revert to their original levels, except for the streptococci and the staphylococci populations. The treatment also led to an increase in acetic acid, CH 4 and CO 2 production, suggesting overgrowth of some anaerobic bacteria. Ammonium, generally considered as undesirable, declined. Conclusions: The whey retentate clearly altered the microbial community in the SHIME. Signi®cance and Impact of the Study: Whey retentate appears to exert a bene®cial effect on the in vitro gastrointestinal system; these ®ndings warrant con®rmation by in vivo studies.
Current Microbiology, 1990
A study on strains received as Pseudomonas alcaligenes was performed by the DNA-DNA hybridization... more A study on strains received as Pseudomonas alcaligenes was performed by the DNA-DNA hybridization procedure. Results on strains phenotypically distinct (subcluster A~; Gavini et al., Int J Syst Bacteriol [1989] 39:135-144) from P. alcaligenes strains (subcluster B~) pointed out that (a) these strains belonged to Comamonas testosteroni species (DNA-DNA homology 75%-98%) and (b) the two species could be differentiated by biochemical tests other than type of flagellation or poly-/3-hydroxybutyrate deposits.
Comparative Immunology, Microbiology and Infectious Diseases, 1992
Studies were undertaken to determine the regulation of the bacterial intestinal implantation in 1... more Studies were undertaken to determine the regulation of the bacterial intestinal implantation in 19 newborns delivered by caesarian section. Correlation was made with the infant feeding mode. The effect of human milk seemed to be the result of B. bifidum proliferation, in contrast to artificial alimentation that seemed to favour C. perfringens implantation. The question was raised by us as to whether this opposition was only related to alimentation. In fact, B. bifidum itself also had an effect as demonstrated by the lower mean counts of C. perfringens in bottle-fed infants carrying the bifidobacterial flora (P = 0.05). None of the other faecal bacteria investigated in this study led to the same decrease.
Journal of Pediatric Gastroenterology and Nutrition, 2004
Archives De Pediatrie, May 1, 2000
Les propriMs anti-infectieuses de l'allaitement maternel reposent non seulement sur la prksence d... more Les propriMs anti-infectieuses de l'allaitement maternel reposent non seulement sur la prksence de facteurs asp& cifiques (gynolactose, mucines) et spkifiques de l'immunitk (immunoglobulines, cellules) mais encore sur la capacitk & stimuler une sCrie de rkponses chew le nour-r&on. Ainsi, la tlore intestinale du nourrisson allait au sein est majoritairement composke de Rifidohucteriunz. qui s'implante 4-S jours aprks la naissance par voie basse (trrbleuu I). Or, ces germes anakrobies de morphologie en Y se distinguent des autres bactkries h Gram positif du biotope intestinal par des propriMs immunostimulantes spkifiques. Chez l'animal. elles induisent une maturation de I'immunitt! cellulaire qui rCgule la translocation d'E.sc/zerichrr
Microbial Ecology in Health & Disease, 1989
The buffering capacity of a milk diet is known to be involved in the control of a newborn's bifid... more The buffering capacity of a milk diet is known to be involved in the control of a newborn's bifidobacterial flora. Other factors could modulate the bifidobacterial flora e.g. bifidus factors present in human milk, which are growth-promoting for Bi3dobacterium bi$durn. The aim of this study was to investigate in gnotobiotic mice the effects of human milk bifidus factors upon colonisation by bifidobacteria according to the dietary buffering capacity. A high buffering capacity diet encouraged the implantation of higher numbers of bifidobacteria in monoxenic mice than a low buffering capacity one. However, supplementary feeding with human milk oligosaccharides (gynolactose) did not support the proliferation of B. bijdum, although the gynolactose bifidus factors were not destroyed during digestion. Furthermore the addition of gynolactose to a high buffering capacity diet led to the breakdown of some of the intestinal glycoproteins detected in the bifidogenic extract of stools from germfree mice. In addition, although the human milk oligosaccharides stimulated the excretion of intestinal bifidus factors when supplementing a low buffering capacity diet, they failed to do so on a high buffering capacity diet. These results suggest that the ability of human milk oligosaccharides to encourage the proliferation of B. bijidum depends upon their capacity to stimulate intestinal bifidus factors. This capacity seemed to be related to the buffering capacity of the diet.
Journal of Pediatric Gastroenterology and Nutrition, 2004
FEMS Microbiology Letters, 1998
Resistance to the combination of amoxicillin and clavulanic acid in some Bacteroides fragilis str... more Resistance to the combination of amoxicillin and clavulanic acid in some Bacteroides fragilis strains may be associated with a lack of porin proteins. Comparison of outer membrane protein profiles from one resistant strain (B. fragilis CFPL 358) and two susceptible strains of B. fiagilis (ATCC 25285 and CFPL 92125) showed that a few proteins were missing in the resistant strain, especially a 45-kDa protein. To determine whether this protein was a porin-like protein, we attempted to isolate it from the two susceptible strains by using gel filtration (Sephacryl S-200, Superose 6) and ion exchange chromatographies (DEAE Trisacryl, DEAE Sepharose Fast Flow). Elution from DEAE resins was poor compared to the 60-67-kDa region, which suggested that the 45-kDa protein exhibited stronger cationic forms. The use of sodium dodecyl sulfate during elution improved the recovery of the 45-kDa protein, showing that detergent modified its conformation and its ionic bounds with the chromatographic matrices but it was not sufficient for good purification. Superose 6 gel filtration also failed to separate this protein from the 60-67-kDa region. The only method resulting in the positive recovery of a purified 45-kDa band from both susceptible B. jiragilis strains was electroelution from SDS-PAGE. The swelling assay showed that the 45-kDa protein was a porin-like protein. From this study, we concluded that the 45-kDa protein from B. fragilis was a porin-like protein which might be involved in the antibiotic resistance of a strain in which this protein was missing.
Journal of Dairy Science, 2002
Cell-free whey obtained from milk fermented with Bifidobacterium breve C50 (Bb C50) has been show... more Cell-free whey obtained from milk fermented with Bifidobacterium breve C50 (Bb C50) has been shown to modify the intestinal flora in humans and mice. Previous work showed that no antibiotic-like or barrier effect due to overgrowing bifidobacteria was implied in the microbial modifications. The present study was focused on characterizing the compounds and mechanisms involved. Protein, sugar, and enzymatic profiles of Bb C50 whey were therefore determined and compared to those of a whey unable to modify the intestinal flora of humans and mice. No remarkable difference was noted except for a higher lactosidase activity in Bb C50 whey. Various physical treatments were then applied to fractions of Bb C50 whey. Activity was assessed in C3H mice by analyzing changes in the intestinal flora balance throughout a 15-d administration of each treated whey. Heating at 80°C and aerobic storage for 2 wk completely abolished Bb C50 whey activities. In contrast, the addition of a reducing agent (cysteine hydrochloride), either at the beginning of a 15-d aerobic storage or prior to administration, as well as preserved these activities. Susceptibility to heating and oxidation suggested that an enzyme might play a role in the induced microbial changes. Since the Bb C50 lactosidase was partly inactivated by the oxidative treatment, it could support the in vivo activity. The enzyme might reach the intestinal lumen and partly degrade substrates, such as mucins, usually used by the intestinal flora. The released molecules might then favor the development of a new microbial balance.