Natalia Belkova - Academia.edu (original) (raw)

Papers by Natalia Belkova

Journal of the Endocrine Society

Childhood obesity is a worldwide serious health issue leading to endocrine disruption. Childhood ... more Childhood obesity is a worldwide serious health issue leading to endocrine disruption. Childhood obesity risk factors are numerous, and in recent decades the significant impact of gut microbiota in the development of obesity has been shown (1). In turn, gut microbiota development can be disrupted by many factors in the early postnatal period, particularly by breastfeeding duration. Although studies were pointing out the impact of short breastfeeding period on the obesity-associated microbiota formation in childhood (2), the long-termed effect still remains poorly explored. Therefore, we assumed a contribution of breastfeeding duration to the gut microbiota composition in adolescents with obesity. The total cohort was 40 adolescents who were divided into four categories: 9 obese and 11 healthy adolescents who had been breastfed less than four months (SDS BMI=2.83±0.40 and SDS BMI=-0.17±0.55 correspondingly); 9 obese and 11 healthy adolescents who had been breastfed more than four mon...

Life

Abnormalities in gut microbiota diversity are considered important mechanisms in metabolic disord... more Abnormalities in gut microbiota diversity are considered important mechanisms in metabolic disorders in polycystic ovarian syndrome (PCOS). However, the data on the association of these disorders with the PCOS phenotype remain controversial. The objectives of this study were to estimate the alpha diversity of the gut microbiota of healthy women and PCOS patients depending on phenotype. The study participants (184 premenopausal women: 63 with PCOS, 121 without PCOS) were recruited during the annual employment assessment in the Irkutsk Region and the Buryat Republic (Russia) in 2016–2019. For PCOS diagnosis, we used the Rotterdam (2003) criteria and definitions of PCOS phenotypes. Five indexes of alpha diversity (ASV, Shannon, Simpson, Chao, and ACE) were estimated for the gut microbiota in all participants using amplicon metasequencing. As a result, two out of five alpha diversity indexes showed a statistical difference between the non-PCOS and PCOS groups. We did not find a signific...

This study described the investigation of microbial mats that are rich in iron, arsenic, and mang... more This study described the investigation of microbial mats that are rich in iron, arsenic, and manganese in four hydrothermal systems of Kamchatka, Russia namely Vilyuchinskie, Mutnovskie, Nachikinskie, and Malkinskie. The hydrothermal systems (hot springs) are contributing to the metallic and non-metallic mineral resources of Russia such as oil, gas, coal, copper, nickel, cobalt, tin, mercury, lead, zinc, diamond, platinum, gold, and silver. We observed the biogeochemical activities of microorganisms originating from microbial mats. The structure and elemental composition of microbial mats in these hydrothermal systems were studied with optical microscopy and scanning electron microscopy equipped with energy dispersive X-ray analyzer (EDX), whereas the water quality of these springs was measured by using pack tests. Additionally, portable γ-ray analyzer was employed to determine the kind and quantity of γ-ray in the atmospheric condition of sampling areas. Optical and scanning electr...

International Microbiology, 2004

The micromorphological structure of microbial mats (biomats) from the hot springs of the Vilyuchi... more The micromorphological structure of microbial mats (biomats) from the hot springs of the Vilyuchinskaya hydrothermal system, Kamchatka Peninsula, Russia, were investigated. The Vilyuchinskie hot springs had a discharge temperature of 55-56 degrees C and Na-Ca-HCO3-type waters rich in silicic and boric acids. Water and biomats had high concentrations of Fe, Mn, Sr, and As. Enumeration of total bacterial abundance (TBA) demonstrated a low density of bacterial populations. However, the fractions of metabolically active bacteria and respiring iron-oxidizing bacteria in the hot-spring water were high, comprising 68 and 21% of TBA, respectively. Scanning electron microscopy equipped with an energy dispersive X-ray spectrometer (SEM-EDX) showed that unicellular rod-shaped bacteria about 5-microm long predominated in the brown biomats. The mineral capsules of these bacteria contained large amounts of Fe and Si. Extracellular and intracellular particles were observed by transmission electron...

International Journal of Biomedicine

The research objective was to study the spectrum of the vagina and endometrium microorganisms in ... more The research objective was to study the spectrum of the vagina and endometrium microorganisms in women with chronic endometritis (CE) in order to take adequate therapeutic measures. Methods and Results: We did a cross-sectional study in 47 women (average age of 35.38±5.19 years) with histologically confirmed CE. The vaginal microbiota and endometrial biopsies were assessed using microbiological research methods in accordance with the medical technology "Integral assessment of the state of the vaginal microbiota." To identify the share of different types of microorganisms in the structure of the biocenosis, the coefficient of constancy of the species (C) was used. Only 19% of patients had a titer of Lactobacillus spp. within the age norm, while the deficit was observed in 80% of women. Among the representatives of Enterobacteriaecae, Escherichia coli and Klebsiella aerogenes were sown, which are considered to be random species (C=11% and C=2.1%, respectively). The average t...

International Journal of Biomedicine

Background: It is known that in the early postnatal period a variety of factors affect the gut mi... more Background: It is known that in the early postnatal period a variety of factors affect the gut microbiota (GM) composition, including delivery mode. The effect of delivery mode on the human GM in the late postnatal period remains unexplored. A shift of GM composition due to delivery mode may contribute to the development of obesity in adulthood. Methods and Results: The study included six adolescents aged between 11 and 17 years treated and examined at the Clinic of the Scientific Center for Family Health and Human Reproduction (Irkutsk, Russia) in 2016. Stool samples were collected following the standard operating procedures according to the International Human Microbiome Standards. Metasequencing of V3-V4 variable regions of the 16S rRNA gene was performed by the Novogene Company (China) on the Illumina platform. Bioinformatic analysis was done by the bri-shur.com services. Sequencing reads were presented as normalized values. In general, the GM composition of obese adolescents bo...

Data in Brief

For the metagenomic characterization of potential taxonomic and functional diversity of microorga... more For the metagenomic characterization of potential taxonomic and functional diversity of microorganisms associated with polycystic ovary syndrome (PCOS) in women, we surveyed five women with PCOS and collected samples of feces, saliva, and serum. After quality processing, we have obtained from 915,594 to 3,880,379 reads; these 16,693 sequences had ribosomal RNA genes, 2,091,990 sequences contained predicted proteins with known functions, and 3,750,261 sequences had predicted proteins with unknown functions. Host DNA accounted for ca. 0.03% and less in datasets of fecal samples, from 1.41 to 24.94% in saliva samples; the remaining sequences were attributed to archaeal, bacterial, or viral DNA. In serum, from 38.18 to 75.77% were characterized as fragments of the human genome, but the remaining sequences were unidentified. Among microbes, a total of one archaeal and eight bacterial phyla were revealed. Viral DNA was detected in several fecal and one saliva sample and was classified as C2likevirus, Flavivirus, and Streptococcus bacteriophage. The metagenome sequence data were deposited at NCBI SRA as BioProject No. PRJNA625611.

Journal of Oceanology and Limnology

F1000Research

Background: The study of ecosystems of the great lakes is important as observations can be extend... more Background: The study of ecosystems of the great lakes is important as observations can be extended to ecosystems of larger scale. The ecological crisis of Lake Baikal needs investigations to discover the molecular mechanisms involved in the crisis. The disease of Baikal sponges is one of the processes resulting in the degradation of the littoral zone of the lake. Methods: The chloroplast genome fragment for the algae endosymbiont of Baikal sponge was assembled from metagenomic sequencing data. The distributions of polymorphic sites were obtained for the genome fragment, separately for samples from healthy sponge, diseased sponge and dead sponge tissues. Results: The comparative analysis of chloroplast genome sequences suggests that the symbiotic algae from Baikal sponge is close to Choricystis genus of unicellular algae. Also, the distributions of polymorphic sites allowed detection of the signs of extensive mutations in the chloroplasts isolated from the diseased sponge tissues. C...

Natural Product Research, 2016

International Microbiology, Sep 1, 2004

Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland, 2016

Diplomonadida are primitive flagellate protozoa, among which both commensals and pathogens have b... more Diplomonadida are primitive flagellate protozoa, among which both commensals and pathogens have been recorded. To date, members of the genera Hexamita and Spironucleus have been reported in the digestive system of fish in the Baikal region. We determined the genetic diversity of Diplomonadida in fish of the genus Coregonus from south-eastern Siberia using molecular-genetic methods. Fish for analysis were caught in Lake Baikal and in the Barguzin, Nepa, Chechuy, and Kirenga rivers from 2010 to 2013. Gall bladders, hindguts and foreguts of 120 specimens of Coregonus migratorius representing three morpho-ecological groups, 25 specimens of Coregonus lavaretus baicalensis, 25 specimens of Coregonus tugun and 30 specimens of Coregonus lavaretus pidschian were analysed via amplification with primers specifically designed for eukaryotes. Amplicons positive for Diplomonadida were sequenced. A phylogenetic analysis revealed that diplomonad flagellates of whitefish from Southeastern Siberia be...

Fundamental and Applied Limnology / Archiv für Hydrobiologie

International Microbiology, Sep 1, 2004

Journal of the Endocrine Society

Childhood obesity is a worldwide serious health issue leading to endocrine disruption. Childhood ... more Childhood obesity is a worldwide serious health issue leading to endocrine disruption. Childhood obesity risk factors are numerous, and in recent decades the significant impact of gut microbiota in the development of obesity has been shown (1). In turn, gut microbiota development can be disrupted by many factors in the early postnatal period, particularly by breastfeeding duration. Although studies were pointing out the impact of short breastfeeding period on the obesity-associated microbiota formation in childhood (2), the long-termed effect still remains poorly explored. Therefore, we assumed a contribution of breastfeeding duration to the gut microbiota composition in adolescents with obesity. The total cohort was 40 adolescents who were divided into four categories: 9 obese and 11 healthy adolescents who had been breastfed less than four months (SDS BMI=2.83±0.40 and SDS BMI=-0.17±0.55 correspondingly); 9 obese and 11 healthy adolescents who had been breastfed more than four mon...

Life

Abnormalities in gut microbiota diversity are considered important mechanisms in metabolic disord... more Abnormalities in gut microbiota diversity are considered important mechanisms in metabolic disorders in polycystic ovarian syndrome (PCOS). However, the data on the association of these disorders with the PCOS phenotype remain controversial. The objectives of this study were to estimate the alpha diversity of the gut microbiota of healthy women and PCOS patients depending on phenotype. The study participants (184 premenopausal women: 63 with PCOS, 121 without PCOS) were recruited during the annual employment assessment in the Irkutsk Region and the Buryat Republic (Russia) in 2016–2019. For PCOS diagnosis, we used the Rotterdam (2003) criteria and definitions of PCOS phenotypes. Five indexes of alpha diversity (ASV, Shannon, Simpson, Chao, and ACE) were estimated for the gut microbiota in all participants using amplicon metasequencing. As a result, two out of five alpha diversity indexes showed a statistical difference between the non-PCOS and PCOS groups. We did not find a signific...

This study described the investigation of microbial mats that are rich in iron, arsenic, and mang... more This study described the investigation of microbial mats that are rich in iron, arsenic, and manganese in four hydrothermal systems of Kamchatka, Russia namely Vilyuchinskie, Mutnovskie, Nachikinskie, and Malkinskie. The hydrothermal systems (hot springs) are contributing to the metallic and non-metallic mineral resources of Russia such as oil, gas, coal, copper, nickel, cobalt, tin, mercury, lead, zinc, diamond, platinum, gold, and silver. We observed the biogeochemical activities of microorganisms originating from microbial mats. The structure and elemental composition of microbial mats in these hydrothermal systems were studied with optical microscopy and scanning electron microscopy equipped with energy dispersive X-ray analyzer (EDX), whereas the water quality of these springs was measured by using pack tests. Additionally, portable γ-ray analyzer was employed to determine the kind and quantity of γ-ray in the atmospheric condition of sampling areas. Optical and scanning electr...

International Microbiology, 2004

The micromorphological structure of microbial mats (biomats) from the hot springs of the Vilyuchi... more The micromorphological structure of microbial mats (biomats) from the hot springs of the Vilyuchinskaya hydrothermal system, Kamchatka Peninsula, Russia, were investigated. The Vilyuchinskie hot springs had a discharge temperature of 55-56 degrees C and Na-Ca-HCO3-type waters rich in silicic and boric acids. Water and biomats had high concentrations of Fe, Mn, Sr, and As. Enumeration of total bacterial abundance (TBA) demonstrated a low density of bacterial populations. However, the fractions of metabolically active bacteria and respiring iron-oxidizing bacteria in the hot-spring water were high, comprising 68 and 21% of TBA, respectively. Scanning electron microscopy equipped with an energy dispersive X-ray spectrometer (SEM-EDX) showed that unicellular rod-shaped bacteria about 5-microm long predominated in the brown biomats. The mineral capsules of these bacteria contained large amounts of Fe and Si. Extracellular and intracellular particles were observed by transmission electron...

International Journal of Biomedicine

The research objective was to study the spectrum of the vagina and endometrium microorganisms in ... more The research objective was to study the spectrum of the vagina and endometrium microorganisms in women with chronic endometritis (CE) in order to take adequate therapeutic measures. Methods and Results: We did a cross-sectional study in 47 women (average age of 35.38±5.19 years) with histologically confirmed CE. The vaginal microbiota and endometrial biopsies were assessed using microbiological research methods in accordance with the medical technology "Integral assessment of the state of the vaginal microbiota." To identify the share of different types of microorganisms in the structure of the biocenosis, the coefficient of constancy of the species (C) was used. Only 19% of patients had a titer of Lactobacillus spp. within the age norm, while the deficit was observed in 80% of women. Among the representatives of Enterobacteriaecae, Escherichia coli and Klebsiella aerogenes were sown, which are considered to be random species (C=11% and C=2.1%, respectively). The average t...

International Journal of Biomedicine

Background: It is known that in the early postnatal period a variety of factors affect the gut mi... more Background: It is known that in the early postnatal period a variety of factors affect the gut microbiota (GM) composition, including delivery mode. The effect of delivery mode on the human GM in the late postnatal period remains unexplored. A shift of GM composition due to delivery mode may contribute to the development of obesity in adulthood. Methods and Results: The study included six adolescents aged between 11 and 17 years treated and examined at the Clinic of the Scientific Center for Family Health and Human Reproduction (Irkutsk, Russia) in 2016. Stool samples were collected following the standard operating procedures according to the International Human Microbiome Standards. Metasequencing of V3-V4 variable regions of the 16S rRNA gene was performed by the Novogene Company (China) on the Illumina platform. Bioinformatic analysis was done by the bri-shur.com services. Sequencing reads were presented as normalized values. In general, the GM composition of obese adolescents bo...

Data in Brief

For the metagenomic characterization of potential taxonomic and functional diversity of microorga... more For the metagenomic characterization of potential taxonomic and functional diversity of microorganisms associated with polycystic ovary syndrome (PCOS) in women, we surveyed five women with PCOS and collected samples of feces, saliva, and serum. After quality processing, we have obtained from 915,594 to 3,880,379 reads; these 16,693 sequences had ribosomal RNA genes, 2,091,990 sequences contained predicted proteins with known functions, and 3,750,261 sequences had predicted proteins with unknown functions. Host DNA accounted for ca. 0.03% and less in datasets of fecal samples, from 1.41 to 24.94% in saliva samples; the remaining sequences were attributed to archaeal, bacterial, or viral DNA. In serum, from 38.18 to 75.77% were characterized as fragments of the human genome, but the remaining sequences were unidentified. Among microbes, a total of one archaeal and eight bacterial phyla were revealed. Viral DNA was detected in several fecal and one saliva sample and was classified as C2likevirus, Flavivirus, and Streptococcus bacteriophage. The metagenome sequence data were deposited at NCBI SRA as BioProject No. PRJNA625611.

Journal of Oceanology and Limnology

F1000Research

Background: The study of ecosystems of the great lakes is important as observations can be extend... more Background: The study of ecosystems of the great lakes is important as observations can be extended to ecosystems of larger scale. The ecological crisis of Lake Baikal needs investigations to discover the molecular mechanisms involved in the crisis. The disease of Baikal sponges is one of the processes resulting in the degradation of the littoral zone of the lake. Methods: The chloroplast genome fragment for the algae endosymbiont of Baikal sponge was assembled from metagenomic sequencing data. The distributions of polymorphic sites were obtained for the genome fragment, separately for samples from healthy sponge, diseased sponge and dead sponge tissues. Results: The comparative analysis of chloroplast genome sequences suggests that the symbiotic algae from Baikal sponge is close to Choricystis genus of unicellular algae. Also, the distributions of polymorphic sites allowed detection of the signs of extensive mutations in the chloroplasts isolated from the diseased sponge tissues. C...

Natural Product Research, 2016

International Microbiology, Sep 1, 2004

Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland, 2016

Diplomonadida are primitive flagellate protozoa, among which both commensals and pathogens have b... more Diplomonadida are primitive flagellate protozoa, among which both commensals and pathogens have been recorded. To date, members of the genera Hexamita and Spironucleus have been reported in the digestive system of fish in the Baikal region. We determined the genetic diversity of Diplomonadida in fish of the genus Coregonus from south-eastern Siberia using molecular-genetic methods. Fish for analysis were caught in Lake Baikal and in the Barguzin, Nepa, Chechuy, and Kirenga rivers from 2010 to 2013. Gall bladders, hindguts and foreguts of 120 specimens of Coregonus migratorius representing three morpho-ecological groups, 25 specimens of Coregonus lavaretus baicalensis, 25 specimens of Coregonus tugun and 30 specimens of Coregonus lavaretus pidschian were analysed via amplification with primers specifically designed for eukaryotes. Amplicons positive for Diplomonadida were sequenced. A phylogenetic analysis revealed that diplomonad flagellates of whitefish from Southeastern Siberia be...

Fundamental and Applied Limnology / Archiv für Hydrobiologie

International Microbiology, Sep 1, 2004