2026-10-16 理化学研究所,千葉大学,兵庫医科大学,高知大学,東北大学,富山大学
年上のきょうだいと幼児の腸内環境との関連
＜関連情報＞
- https://www.riken.jp/press/2026/20261016_1/index.html
- https://www.nature.com/articles/s41390-026-05478-3
就学前児童の腸内細菌叢および糞便中の短鎖脂肪酸に関連する兄弟姉妹因子 Sibling factors associated with gut microbiota and fecal short-chain fatty acids in preschoolers
Yuichiro Tanaka, Ryohei Shibata, Yumiko Nakanishi, Tamotsu Kato, Bahrul Fikri, Tomoko Takahashi, Kenichi Sakurai, Midori Yamamoto, Masayuki Shima, Yasuhiro Takeshima, Narumi Tokuda, Taku Oishi, Narufumi Suganuma, Kahoko Yasumitsu-Lovell, Takahiro Arima, Hiroshi Kitazawa, Nobuo Yaegashi, Yuichi Adachi, Hidekuni Inadera, Shokei Murakami, Chisato Mori, Naoki Shimojo & Hiroshi Ohno
Pediatric Research Published:14 October 2026
DOI:https://doi.org/10.1038/s41390-026-05478-3
Abstract
Background
Sibling factors are linked not only to disease development but also to gut environmental factors (e.g., microbiota, short-chain fatty acids [SCFA]). However, these associations among preschoolers and their underlying mechanisms remain unclear.
Methods
In a sub-cohort study of a nationwide birth-cohort study, using fecal microbiome and SCFA data from 903 children at age 2 or 4 years, we examined associations of sibling factors with gut environmental factors. We also determined enterotypes by clustering and sibling-enterotype associations with potential mediation pathways.
Results
Among sibling factors, the number of older siblings showed the strongest associations with gut environmental factors. We identified 3 enterotypes: 1) Mediterraneibacter gnavus group, 2) Faecalibacterium, and 3) Ruminococcus. Compared to enterotype 2, having older siblings was associated with lower odds of enterotype 1, with the lowest Shannon index and propionate level, at age 2 (1 sibling: adjOR 0.49, 95%CI 0.34–0.69; ≥2: adjOR 0.32, 95%CI, 0.19–0.54) and 4 (1 sibling: adjOR 0.45, 95%CI 0.26–0.77; ≥2: adjOR 0.22, 95%CI 0.08–0.53) years. These associations were largely direct, with modest mediation by antibiotic use at age 4 years (1 sibling, adjOR 0.89; 95%CI, 0.79–1.00).
Conclusion
Our data identified distinct enterotypes of preschoolers and sibling–enterotype association pathways.
Impact
- In this nationwide multicenter birth-cohort sub-cohort, older siblings were strongly associated with gut microbial composition in preschoolers.
- Having older siblings was associated with lower odds of a potentially less mature enterotype characterized by the lowest Shannon index and propionate level.
- The sibling–enterotype association was mainly direct, with modest mediation by recent antibiotic use.
- This study extends sibling–microbiota evidence beyond infancy/toddlerhood by identifying three enterotypes with distinct microbial and short-chain fatty acid profiles.
- These findings clarify pathways linking family structure to gut environmental development and may inform microbiota-targeted disease prevention strategies.
