Department of Medicine, University of Alberta, Edmonton, AB, Canada.
Psychoneuroendocrinology. 2013 Sep;38(9):1738-47. doi: 10.1016/j.psyneuen.2013.02.008. Epub 2013 Apr 6.
Modulation of the gut microbiota with diet and probiotic bacteria can restore intestinal homeostasis in inflammatory conditions and alter behavior via the gut-brain axis. The purpose of this study was to determine whether the modulatory effects of probiotics differ depending on diet and mouse genotype. At weaning, wild type (WT) and IL-10 deficient (IL-10(-/-)) 129/SvEv mice were placed on a standard mouse chow or a Western-style diet (fat 33%, refined carbohydrate 49%)±Lactobacillus helveticus ROO52 (10(9)cfu/d) for 21 days. Animal weight and food eaten were monitored weekly. Intestinal immune function was analysed for cytokine expression using the Meso Scale Discovery platform. Spatial memory and anxiety-like behavior was assessed in a Barnes maze. Terminal restriction fragment length polymorphism (TRFLP) was used to analyze the fecal microbiota. Both WT and IL-10(-/-) mice on a Western diet had increased weight gain along with changes in gut microbiota and cytokine expression and altered anxiety-like behavior. The ability of L. helveticus to modulate these factors was genotype- and diet-dependent. Anxiety-like behavior and memory were negatively affected by Western-style diet depending on inflammatory state, but this change was prevented with L. helveticus administration. However, probiotics alone decreased anxiety-like behavior in WT mice on a chow diet. Mice on the Western diet had decreased inflammation and fecal corticosterone, but these markers did not correlate with changes in behavior. Analysis of bacterial phyla from WT and IL-10(-/-)mice showed discrete clustering of the groups to be associated with both diet and probiotic supplementation, with the diet-induced shift normalized to some degree by L. helveticus. These findings suggest that the type of diet consumed by the host and the presence or absence of active inflammation may significantly alter the ability of probiotics to modulate host physiological function.
通过饮食和益生菌调节肠道菌群可以在炎症状态下恢复肠道内环境平衡，并通过肠道-大脑轴改变行为。本研究旨在确定益生菌的调节作用是否因饮食和小鼠基因型而异。在断奶时，将野生型（WT）和白细胞介素 10 缺陷（IL-10(-/-)）129/SvEv 小鼠分别置于标准鼠粮或西式饮食（脂肪 33%，精制碳水化合物 49%）±瑞士乳杆菌 ROO52（10(9)cfu/d）中 21 天。每周监测动物体重和食物摄入量。使用 Meso Scale Discovery 平台分析肠道免疫功能的细胞因子表达。在 Barnes 迷宫中评估空间记忆和焦虑样行为。末端限制性片段长度多态性（TRFLP）用于分析粪便微生物群。Western 饮食的 WT 和 IL-10(-/-) 小鼠体重增加，肠道菌群和细胞因子表达发生变化，焦虑样行为改变。瑞士乳杆菌调节这些因素的能力取决于基因型和饮食。根据炎症状态，Western 饮食会导致焦虑样行为和记忆受到负面影响，但通过瑞士乳杆菌的给药可以预防这种变化。然而，益生菌单独给药会降低 Chow 饮食的 WT 小鼠的焦虑样行为。Western 饮食的小鼠炎症和粪便皮质酮减少，但这些标志物与行为变化无关。对 WT 和 IL-10(-/-) 小鼠的细菌门分析表明，这些组的聚类与饮食和益生菌补充都有关，Western 饮食引起的变化在某种程度上通过瑞士乳杆菌得到了纠正。这些发现表明，宿主所消耗的饮食类型以及是否存在活跃的炎症可能会极大地改变益生菌调节宿主生理功能的能力。
