Differences in Gut Microbiota Composition and Predicted Metabolic Functions: a Pilot Study of Adolescents with Normal Weight and Obesity.

Understanding the principles underlying the stability and sustainability of the gut microbiome of adolescents with normal weight and obesity will make it possible to implement a personalized approach to the correction of metabolic disorders. The article presents the results of a pilot study of the diversity and metabolic potential of the gut microbiome in adolescents with normal body weight and obesity. Biological material was studied using metagenomic sequencing of the V3-V4 variable regions of the 16S rRNA gene. In all adolescents with normal weight, similar degree of the phylogenetic relationship between the bacterial taxa of the community was demonstrated. In contrast, obese adolescents were characterized by the presence of phylogenetically distinct taxa in the gut microbiota. However, even with differences in taxonomic composition, the gut microbial community can compensate for the absence of certain taxonomic groups by implementing the necessary metabolic functions using other phylogenetically close taxa.

Diversity and Metabolic Potential of the Gut Microbiome in Adolescents with Functional Bowel Disorder.

The article presents the results of a pilot study of the diversity and metabolic potential of the gut microbiome in adolescents with various forms of functional bowel disorder. The participants were the patients of the Clinic of Research Center for Family Health and Human Reproduction Problems. Biological material was studied using metagenomic sequencing of V3-V4 variable regions of the 16S rRNA gene. We showed that the composition of the minor component of the intestinal microbiome in adolescents with functional bowel disorder differs from that in the healthy subjects (control). Different types of transit disturbances in functional bowel disorder also differ from each other. According to the metabolic potential, adolescents can be divided into two groups irrespective of the pathophysiological manifestations: for one group, a more intensive metabolism in amino acid and lipid biosynthesis pathways was predicted than for the other.

The relationship between the composition of the microbiota and functional intestinal disorders in obese adolescents.

Functional gastrointestinal disorders (FGIDs) in children and adolescents are one of the most common pathologies of the digestive tract. The aim of the study was to study the structure of the colon microbiota in obese adolescents and to establish its relationship with the clinical manifestations of the disease FGIDs. The study included 20 adolescents aged 11-17 years. The main group included 13 adolescents with a clinically confirmed diagnosis of obesity (the standard deviation of the body mass index (SDS BMI) is more than 2,0) in combination with FGIDs. The control group consisted of 7 adolescents with normal body weight and no abdominal complaints (SDS BMI=0,66). Clinical symptoms from the bowel re diagnosed on the basis of the Rome IV. The consistency of feces was evaluated using the Bristol Stool Form Scale. The study of biological material was carried out by standard bacteriological methods. It is shown that in adolescents with obesity and FGIDs, there is a decrease in the concentration of representatives of bifidoflora, an increase in the microbial density of Escherichia coli with altered properties and an excessive growth of potentially pathogenic enterobacteria. It is established that the presence of conditionally pathogenic bacteria is sem. Enterobacteriaceae is associated with abdominal pain during defecation. In obese adolescents in the group with unformed stools, Clostridium spp was recorded as part of the intestinal microbiota.

Metasequencing of V3-V4 Variable Regions of 16S rRNA Gene in Opportunistic Microbiota and Gut Biocenosis in Obese Adolescents.

Opportunistic microorganisms in the gut biocenosis were studied in adolescents with normal body weight and obesity (patients consulted at the Clinical Department of Research Center of Family Health and Human Reproduction Problems). The biological material was studied by standard bacteriological methods, representatives of Enterobacteriaceae family were also characterized using metagenomic sequencing of V3-V4 variable regions of 16S gene rRNA. Gut microbiota of obese adolescents was unbalanced and was characterized by low levels of bifido- and lactoflora representatives, a spectrum of E. coli associations, and high prevalence of opportunistic microorganisms and their associations. Representatives of Enterobacteriaceae family were most often found in the gut microbiota of obese adolescents.

Composition and Structure of Gut Microbiome in Adolescents with Obesity and Different Breastfeeding Duration.

Gut microbiome of adolescents with obesity and different duration of breastfeeding was analyzed by metagenomic analysis of V3-V4 variable domains of the 16S rRNA gene. In subgroup with breastfeeding duration <3 months, intrapopulation structure of gut microbiome by alpha diversity indices was similar in adolescents with obesity and normal body weight. The decrease in phylotype abundance in the structure of communities was associated only with obesity, while dysbiotic state persisted in both lean and overweight adolescents, which confirmed the effect of breastfeeding duration on stability of gut microbiome.