# An Exploratory Study on Seasonal Variation in the Gut Microbiota of Athletes: Insights from Japanese Handball Players

## TL;DR

This study explores how the gut microbiota of Japanese handball players changes with seasons and differs from non-athletes.

## Contribution

The study reveals seasonal changes in gut microbiota diversity and composition in athletes, particularly during the off-season.

## Key findings

- Athletes had higher gut microbiota alpha-diversity and more Faecalibacterium and Streptococcus compared to non-athletes.
- Alpha-diversity in athletes significantly changed between athletic and off-season periods.
- During the off-season, no significant difference in alpha-diversity was observed between athletes and non-athletes.

## Abstract

Despite accumulating evidence that suggests a unique gut microbiota composition in athletes, a comprehensive understanding of this phenomenon is lacking. Furthermore, seasonal variation in the gut microbiota of athletes, particularly during the off-season, remains underexplored. This study aimed to compare the gut microbiotas between athletic subjects (AS) and non-athletic subjects (NS), and to investigate variations between athletic and off-season periods. The data were derived from an observational study involving Japanese male handball players. The results revealed a distinct gut microbiota composition in AS compared with NS, characterized by significantly higher alpha-diversity and a greater relative abundance of Faecalibacterium and Streptococcus. Moreover, a comparative analysis between athletic and off-season periods in AS demonstrated a significant change in alpha-diversity. Notably, AS exhibited significantly higher alpha-diversity than NS during the athletic season, but no significant difference was observed during the off-season. This study demonstrates the characteristics of the gut microbiota of Japanese handball players and highlights the potential for changes in alpha-diversity during the off-season. These findings contribute to our understanding of the dynamic nature of the gut microbiota of athletes throughout the season.