Choi Jungmi, Takeda Midori, Managi Shunsuke
Urban Institute, Kyushu University, Fukuoka, Japan.
Front Nutr. 2025 Jun 30;12:1609102. doi: 10.3389/fnut.2025.1609102. eCollection 2025.
The gut microbiome plays a central role in human health and can be shaped by both dietary and environmental factors. While yogurt has been widely studied for its ability to modulate the gut microbiota as a dietary factor, the effects of chloride hot spring bathing as an environmental factor remain largely unexplored. This randomized, controlled trial investigated the individual and combined effects of yogurt consumption and chloride hot spring bathing on gut microbiota, fecal metabolites, and defecation function in healthy adults. 47 participants (39 eligible participants + 8 additional recruits) were randomly assigned to one of three groups: control, yogurt only, or yogurt plus hot spring bathing. Over a four-week period, participants in the yogurt groups consumed 180 g of yogurt daily, and those in the hot spring group additionally bathed in a chloride-rich hot spring at least every 2 days. Fecal samples and defecation status questionnaires were collected before and after the intervention. Gut microbiota profiles were analyzed using 16S rRNA gene sequencing, and short-chain fatty acids (SCFAs) were measured by gas chromatography-mass spectrometry (GC-MS). Yogurt consumption significantly increased gut microbial diversity, as shown by higher Shannon index, observed ASVs, and Faith's phylogenetic diversity, with notable enrichment of beneficial taxa such as . A significant reduction in formic acid levels was also observed in the yogurt group, while overall SCFA profiles remained unchanged. Although no significant microbiota or metabolite shifts were detected in the yogurt + hot spring group, it showed the greatest numerical improvement in defecation scores. These findings suggest that accessible lifestyle interventions, such as dietary modification and hot spring bathing, can positively influence gut health and may serve as practical strategies for promoting overall well-being.
肠道微生物群在人类健康中起着核心作用，并且会受到饮食和环境因素的影响。虽然酸奶作为一种饮食因素调节肠道微生物群的能力已得到广泛研究，但氯化物温泉浴作为一种环境因素的影响在很大程度上仍未得到探索。这项随机对照试验研究了食用酸奶和氯化物温泉浴对健康成年人肠道微生物群、粪便代谢物和排便功能的单独及联合影响。47名参与者（39名符合条件的参与者 + 8名额外招募者）被随机分配到三组中的一组：对照组、仅食用酸奶组或酸奶加温泉浴组。在四周的时间里，酸奶组的参与者每天食用180克酸奶，温泉组的参与者除此之外至少每两天在富含氯化物的温泉中沐浴一次。在干预前后收集粪便样本和排便状况问卷。使用16S rRNA基因测序分析肠道微生物群谱，并通过气相色谱 - 质谱联用（GC-MS）测量短链脂肪酸（SCFAs）。食用酸奶显著增加了肠道微生物多样性，表现为香农指数、观察到的可操作分类单元（ASVs）和费思系统发育多样性更高，有益类群如 显著富集。在酸奶组中还观察到甲酸水平显著降低，而总体短链脂肪酸谱保持不变。虽然在酸奶 + 温泉组中未检测到微生物群或代谢物的显著变化，但它在排便评分方面显示出最大的数值改善。这些发现表明，饮食调整和温泉浴等易于实施的生活方式干预措施可以对肠道健康产生积极影响，并可能成为促进整体健康的实用策略。
