背景:肠道微生物组组成深刻影响宿主生理,并受多种环境因素的调节,最突出的饮食。肠道微生物群的组成在整个生命周期内发生变化,特别是在最早和最新阶段。然而,我们对肠道微生物组的饮食-衰老相互作用知之甚少。我们之前证明了不同血糖指数的饮食,根据快速消化的支链淀粉与缓慢消化的直链淀粉的比例,导致雄性C57BL/6J小鼠肠道菌群组成改变。
目标:这里,我们研究了衰老在影响饮食对肠道菌群组成的影响中的作用,并确定了对饮食和衰老作出反应的肠道细菌类群.
方法:我们研究了三个年龄组的雄性C57BL/6J野生型小鼠:年轻(4个月),中年(13.5个月),和年龄(22个月),所有喂养的高血糖(HG)或低血糖(LG)饮食都与热量含量和大量营养素组成相匹配。通过16SrDNA宏基因组测序确定粪便微生物组组成,并评估α和β多样性以及随年龄变化的细菌分类群的变化,饮食,或者两者兼而有之。
结果:年轻小鼠的α多样性得分低于中年小鼠,但饮食之间的β多样性差异更明显。相比之下,老年小鼠的α多样性得分略低于中年小鼠,具有明显更高的β多样性距离。群体内方差在年轻人中最低,LG喂养的老鼠,年龄最高,HG喂养的小鼠。差异丰度分析显示,分类群与衰老和饮食有关。大多数差异分类群显示出饮食与衰老之间的显着相互作用。值得注意的是,Lachnospirosaceae家族的几个成员随着衰老和HG饮食而增加,而来自拟杆菌属的类群随着LG饮食的增加而增加。Akkermansia粘虫随着年龄的增长而减少。
结论:这些发现说明了饮食和衰老在塑造肠道菌群方面的复杂相互作用,可能导致与年龄有关的疾病。
BACKGROUND: Gut microbiome composition profoundly impacts host physiology and is modulated by several environmental factors, most prominently diet. The composition of gut microbiota changes over the lifespan, particularly during the earliest and latest stages. However, we know less about diet-aging interactions on the gut microbiome. We previously showed that diets with different glycemic indices, based on the ratio of rapidly digested amylopectin to slowly digested amylose, led to altered composition of gut microbiota in male C57BL/6J mice.
OBJECTIVE: Here, we examined the role of aging in influencing dietary effects on gut microbiota composition and aimed to identify gut bacterial taxa that respond to diet and aging.
METHODS: We studied 3 age groups of male C57BL/6J wild-type mice: young (4 mo), middle-aged (13.5 mo), and old (22 mo), all fed either high glycemic (HG) or low glycemic (LG) diets matched for caloric content and macronutrient composition. Fecal microbiome composition was determined by 16S rDNA metagenomic sequencing and was evaluated for changes in α- and β-diversity and bacterial taxa that change by age, diet, or both.
RESULTS: Young mice displayed lower α-diversity scores than middle-aged counterparts but exhibited more pronounced differences in β-diversity between diets. In contrast, old mice had slightly lower α-diversity scores than middle-aged mice, with significantly higher β-diversity distances. Within-group variance was lowest in young, LG-fed mice and highest in old, HG-fed mice. Differential abundance analysis revealed taxa associated with both aging and diet. Most differential taxa demonstrated significant interactions between diet and aging. Notably, several members of the Lachnospiraceae family increased with aging and HG diet, whereas taxa from the Bacteroides_H genus increased with the LG diet. Akkermansia muciniphila decreased with aging.
CONCLUSIONS: These findings illustrate the complex interplay between diet and aging in shaping the gut microbiota, potentially contributing to age-related disease.