Table_1_Gut Microbiota Features in Young Children With Autism Spectrum Disorders.xlsx

Proliferation and/or depletion of clusters of specific bacteria regulate intestinal functions and may interfere with neuro-immune communication and behavior in patients with autism spectrum disorder (ASD). Consistently, qualitative and quantitative alteration of bacterial metabolites may functionally affect ASD pathophysiology. Up to date, age-restricted cohort studies, that may potentially help to identify specific microbial signatures in ASD, are lacking. We investigated the gut microbiota (GM) structure and fecal short chain fatty acids (SCFAs) levels in a cohort of young children (2–4 years of age) with ASD, with respect to age-matched neurotypical healthy controls. Strong increase of Bacteroidetes and Proteobacteria and decrease of Actinobacteria was observed in these patients. Among the 91 OTUs whose relative abundance was altered in ASD patients, we observed a striking depletion of Bifidobacterium longum, one of the dominant bacteria in infant GM and, conversely, an increase of Faecalibacterium prausnitzii, a late colonizer of healthy human gut and a major butyrate producer. High levels of F. prausnitzii were associated to increase of fecal butyrate levels within normal range, and over representation of KEGG functions related to butyrate production in ASD patients. Here we report unbalance of GM structure with a shift in colonization by gut beneficial bacterial species in ASD patients as off early childhood.

特定细菌簇的增殖与/或耗竭可调控肠道功能，并可能干扰自闭症谱系障碍（ASD）患者的神经免疫通讯与行为表现。与此相一致的是，细菌代谢物的质与量改变可在功能层面影响ASD的病理生理过程。迄今为止，尚缺乏能够助力识别ASD特异性微生物特征的年龄受限队列研究。本研究以年龄匹配的神经典型健康个体为对照，针对2~4岁幼儿自闭症谱系障碍患者队列，探究了其肠道菌群（GM）结构与粪便短链脂肪酸（SCFAs）水平。研究观察到，自闭症谱系障碍患者体内拟杆菌门（Bacteroidetes）与变形菌门（Proteobacteria）丰度显著升高，放线菌门（Actinobacteria）丰度降低。在相对丰度发生改变的91个操作分类单元（OTU）中，我们发现长双歧杆菌（Bifidobacterium longum）——婴儿肠道菌群中的优势菌之一——的丰度显著耗竭；与之相反，普拉梭菌（Faecalibacterium prausnitzii）——健康人肠道后期定植菌与主要丁酸产生菌——的丰度显著升高。高水平的普拉梭菌与正常参考范围内的粪便丁酸水平升高相关，且自闭症谱系障碍患者体内富集了与丁酸产生相关的京都基因与基因组百科全书（KEGG）功能通路。本研究揭示，自闭症谱系障碍患者在幼儿早期即出现肠道菌群结构失衡，表现为肠道有益菌的定植模式发生改变。