Division of Pharmacology, Faculty of Pharmaceutical Science, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, 981-8558, Japan.
Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan.
Sci Rep. 2022 Aug 15;12(1):13819. doi: 10.1038/s41598-022-18095-x.
The gut environment, including the microbiota and its metabolites and short-chain fatty acids (SCFA), is essential for health maintenance. It is considered that functional recovery treatment for masticatory dysphagia affects the composition of the gut microbiota, indicating that habitual mastication, depending on the hardness of the food, may affect the gut microbiota and environment. However, the impact of chronic powdered diet feeding on the colonic condition and motility remains unclear. Here, we evaluated various colonic features in mice fed with powdered diets for a long-term and a mouse model with masticatory behavior. We observed a decreased abundance of the SCFA-producing bacterial genera in the ceca of the powdered diet-fed mice. Based on the importance of SCFAs in gut immune homeostasis and motility, interestingly, powdered diet feeding also resulted in constipation-like symptoms due to mild colitis, which were ameliorated by the administration of a neutrophil-depleting agent and neutrophil elastase inhibitors. Lastly, the suppressed colonic motility in the powdered diet-fed mice was significantly improved by loading masticatory activity for 2 h. Thus, feeding habits with appropriate masticatory activity and stimulation may play a key role in providing a favorable gut environment based on interactions between the gut microbiota and host immune system.
肠道环境，包括微生物群及其代谢物和短链脂肪酸（SCFA），对维持健康至关重要。有研究认为，咀嚼吞咽障碍的功能性恢复治疗会影响肠道微生物群的组成，这表明习惯性咀嚼（取决于食物的硬度）可能会影响肠道微生物群和环境。然而，长期食用粉末状饮食对结肠状况和蠕动的影响尚不清楚。在这里，我们评估了长期食用粉末状饮食的小鼠和具有咀嚼行为的小鼠模型的各种结肠特征。我们观察到，在食用粉末状饮食的小鼠的盲肠中，产生 SCFA 的细菌属的丰度降低。鉴于 SCFA 在肠道免疫稳态和蠕动中的重要性，有趣的是，粉末状饮食喂养还会因轻度结肠炎导致类似便秘的症状，而用中性粒细胞耗竭剂和中性粒细胞弹性蛋白酶抑制剂治疗可以改善这些症状。最后，通过加载 2 小时咀嚼活动，可显著改善食用粉末状饮食的小鼠的结肠蠕动。因此，具有适当咀嚼活动和刺激的饮食习惯可能基于肠道微生物群和宿主免疫系统之间的相互作用，在提供有利的肠道环境方面发挥关键作用。
