Effects of high-intensity interval training on gut microbiota profiles in 12 months' old ICR mice.

High-intensity interval training (HIT) has been proposed to exert multiple beneficial effects and positively affect gut microbiota, while how HIT would affect gut microbiota profiles in middle-aged mice remain unreported. Male ICR mice (12 months old) were divided into two groups, i.e., control group (CON) and HIT exercise group (HIT) given HIT running with a total of 7 weeks. Fecal content from the gut was collected eventually and gut microbiota were determined via 16S rRNA gene sequencing. Compared with CON group, mice from HIT group exhibited improved gut microbial diversity including increased Shannon index. Compared with the CON group, at the phylum level, the relative abundance of Proteobacteria and TM7 was significantly decreased and increased, respectively, from HIT group. At the genera level, HIT group had significantly increased Dorea and Dehalobacterium, while decreased Candidatus Arthromitus. PICRUSt analysis at level 2 and level 3 of KEGG pathways demonstrated that the cecal microbiota of mice from HIT group had significantly enriched pathways involved in carbohydrate metabolism, signal transduction mechanisms, and transcription, while reduced pathways involved in renal cell carcinoma, Huntington's disease, pathways in cancer, various types of N-glycan biosynthesis, Alzheimer's disease, glycan biosynthesis and metabolism, lipopolysaccharide biosynthesis, cell motility and secretion, and lipopolysaccharide biosynthesis proteins. In conclusion, HIT could dynamically alter gut microbiota profiles in middle-aged mice. How altered gut microbiota profiles could affect the biological functions of HIT need to be further explored.