Metabolic Changes in Intestinal Microbiota During Physical Activity

Abstract Objective: The aim of our study was to study the metabolic profile of the intestinal microbiota in combat sports athletes to identify specific enzymes and metabolic pathways associated with microbiome adaptation to intense physical activity. Methods: Stool samples were collected from the study participants. Bacterial DNA was isolated from the samples using the QIAamp Fast DNA Stool Mini Kit, followed by sequencing of the v3-v4 variable region of the 16S rRNA gene on the MiSeq platform. The obtained data were analyzed using QIIME v.1.9.1 using the Greengenes v.13.8 reference database with a 97% sequence similarity threshold. Metabolic functions of the intestinal microbiota were predicted using PICRUSt2 software (03), which allowed us to estimate the abundance of enzyme and metabolic pathway genes normalized to the copy number of 16S rRNA reads. Statistical processing of the obtained results was performed using GraphPad Prism v. 10.4.1. Results and Discussion: As a result, the presence of 2186 enzymes and 403 metabolic pathways was predicted in the metabolic profiles of the intestinal microbiota of the study groups. Among the enzymes, increased levels of aromatic amino acid decarboxylase (EC: 4.1.1.28) and pteridine reductase (EC: 1.5.1.33) were observed in the microbiome of athletes. The control group participants were not predicted to have the genes encoding these enzymes in their gut microbiomes, whereas the aromatic L-amino acid decarboxylase gene (EC: 4.1.1.28) was predicted to be present in the microbiome of 61.1% of athletes (p = 0.0001), and the pteridine reductase gene (EC: 1.5.1.33) was predicted to be present in the microbiome of 83.3% of athletes (p < 0.0001). Conclusions: Intense physical activity leads to isolated changes in the metabolic capabilities of the gut microbiota, while the overall metabolic profile of the microbiome is similar to that of non-athletes. In athletes, the gut microbiome is more active in producing and degrading biogenic amines, synthesizing ergothioneine and methyl ketones, and exhibits specific fatty acid synthesis and pterin metabolism. These changes appear to reflect adaptation of the microbiota to intense physical activity.