Author(s): TANIMURA, Y., AKAZAWA, N., NAKAMURA, M., EDA, N., SHIMIZU, K., MURAKAMI, H., NAKAGATA, T., NANRI, H., KAWASHIMA, H., PARK, J., HOSOMI, K., MIZUGUCHI, K., KUNISAWA, J., MIYACHI, M., HOSHIKAWA, M., Institution: JAPAN INSUTITUTE OF SPORTS SCIENCES, Country: JAPAN, Abstract-ID: 1502

INTRODUCTION:
　Athletes need to ensure adequate sleep, which is essential for effective recovery [1]. Recent studies have reported an association between insufficient sleep and a reduction in the production of short-chain fatty acids by the gut microbiota [2]. Another study observed a higher relative abundance of two genes involved in butyric acid synthesis via the lysine pathway in participants with shorter sleep duration [3].
　The aim of this study is to investigate elite Japanese athletes to elucidate the distinctive features, which are the composition and functionality of their gut microbiota, associated with their sleep duration.

METHODS:
A total of 90 elite athletes (24.2 ± 4.4 years old; male/female=51/39; sleep duration, 454.2 ± 51.6 min) competing internationally or representing their respective national teams in various sports participated in this study. Sleep duration was self-reported through a questionnaire. Shotgun analysis was used to obtain data on the microbial composition and KEGG ortholog groups (KOs) present in their fecal samples. Participants were categorized into two sleep groups: short sleep (SS), defined as less than 7 hours on more than 5 nights per week, and normal sleep (NS), defined as 7 hours or more on more than 5 nights per week. Approximately 16% of participants (n=14; 22.9 ± 5.0 years old; male/female=7/7; sleep duration, 368.5 ± 21.7 min) were identified as short sleepers, whereas approximately 84% (n=76; 24.5 ± 4.3 years old; male/female=44/32; sleep duration, 470 ± 38.2 min) fell into the normal sleep category.
RESULTS:
Shotgun analysis of microbial communities revealed no significant differences in β-diversity (Bray-Curtis distance) and α-diversity between groups. Among the strains with an average relative abundance of 0.1% or more in the whole population, Bacteroides fragilis showed a significantly higher relative abundance in the SS group compared to the NS, while Faecalibacterium duncaniae, Blautia massiliensis and Butyricimonas virosa showed a significantly lower relative abundance in the SS group compared to the NS (Wilcoxon rank sum test, adjusted for FDR, q<0.05).
The functional profile exhibited a trend of significant differences in β-diversity between the two groups based on the identified KOs (Adonis2 PERMANOVA, p=0.057). Regarding the α-diversity indices, the SS group had a significantly lower value in the Shannon index, while the SS group had a significantly higher value in the Simpson index.

CONCLUSION:
Differences in sleep duration were suggested to have the impact on the composition and functionality of the microbiota.
REFERENCES:
1. N. P. Walsh, et al. Br J Sports Med 2021; 55: 356-368.
2. Y. Shimizu, et al. Gut Microbes 2023, 15 (1): 2190306. 3. N. Fei, et al. PLoS One 2021, 16(9): e0255323.
3. N. Fei, et al. PLoS One 2021, 16(9): e0255323.