OC26 Features of gut microbiota composition in obese adolescents

Abstract

Introduction Obesity is a multifactorial disease, which may be caused by genetic, psychological causes, obesogenic lifestyle including disturbance in energy balance and a sedentary lifestyle. Gut microbiota takes part in digestion of plant polysaccharides, and also it produces a strong influence on lipid and cholesterol metabolism, therefore gut microbiota dysbiosis may leads to metabolic dysfunction including obesity. Therefore, we made an aim to detect dominant types of gut microbiota at patients with obesity and normal weight and evaluate biochemical parameters of serum alanine transaminase (ALT) and serum alkaline phosphatase (AP), which are obesity-associated metabolic risk factors. Methods The total participant’s number was 40. 18 subjects were obese adolescents (BMI=32,57±4,29 kg/m2), the 22 subjects were healthy adolescents (BMI=20,01±1,66 kg/m2). These two groups were comparable by ethnicity (all participants are Caucasians), gender (10 males and 8 females at the obese group; 13 males and 9 females at the control group), and age (mean age was 14.75±1.52 yrs for obese normal weight and 14.73±1.55 yrs for the normal weight group). Metagenome sequencing of V3-V4 variable regions of 16S rDNA were done by Novogene Company (China). Concentration of serum ALT and AP were measured using Mindray Automatic Biochemistry Analyzer. Data were analyzed using the bioinformatics services bri-shur.com. For group comparison the t-test was used. Statistical significance was accepted at the p≤0.05 level. Results Assessment of OTU in two groups of adolescents – healthy and obesity – revealed the minimal values in the obesity group, the maximal – in the healthy, which showed the decrease in gut microbiome diversity in obesity. There was identified significant difference between gut microbiota composition at the obesity and control groups: the Dorea genus (phylum Firmicutes) dominated at obese patients (p=0.05). Otherwise the groups weren`t significantly different from each other, but there was a tendency of Bacteroides, Parabacteroides (the phylum Bacteroidetes) and Slackia, Collinsella (the phylum Actinobacteria) prevalence at the obesity group (the p≥0.05). Obese adolescents had the mean ALT as 25,34±13,44, and the mean AP was 143,63±83,69, but this is not statistically reliable (p>0,05). The mean ALT of adolescents without obesity was 18,87±13,26, and the mean AP was 165,76±99,01 (p>0,05). Conclusion We report that obese adolescents had higher levels of ALT and lower levels of AP in their serum, and less diverse gut microbiome communities with higher relative abundance of the main bacteria phyla like Firmicutes, Bacteroidetes, Actinobacteria.