The human colon is colonised by a dense microbial community whose species composition and metabolism are linked to health and disease. The main energy sources for colonic bacteria are dietary polysaccharides and oligosaccharides. These play a major role in modulating gut microbial composition and metabolism, which in turn can impact on health outcomes. We investigated the influence of wheat bran arabinoxylan oligosaccharides (AXOS) and maltodextrin supplements in modulating the composition of the colonic microbiota and metabolites in healthy adults over the age of 60. Male and female volunteers, (n = 21, mean BMI 25.2 ± 0.7 kg/m2) participated in the double-blind, cross over supplement study. Faecal samples were collected for analysis of microbiota, short chain fatty acids levels and calprotectin. Blood samples were collected to measure glucose, cholesterol and triglycerides levels. There was no change in these markers nor in calprotectin levels in response to the supplements. Both supplements were well-tolerated by the volunteers. Microbiota analysis across the whole volunteer cohort revealed a significant increase in the proportional abundance of faecal Bifidobacterium species (P ≤ 0.01) in response to AXOS, but not maltodextrin, supplementation. There was considerable inter-individual variation in the other bacterial taxa that responded, with a clear stratification of volunteers as either Prevotella-plus (n = 8; > 0.1% proportional abundance) or Prevotella-minus (n = 13; ≤0.1% proportional abundance) subjects founded on baseline sample profiles. There was a significant increase in the proportional abundance of both faecal Bifidobacterium (P ≤ 0.01) and Prevotella species (P ≤ 0.01) in Prevotella-plus volunteers during AXOS supplementation, while Prevotella and Bacteroides relative abundances showed an inverse relationship. Proportional abundance of 26 OTUs, including bifidobacteria and Anaerostipes hadrus, differed significantly between baseline samples of Prevotella-plus compared to Prevotella-minus individuals. The wheat bran AXOS supplementation was bifidogenic and resulted in changes in human gut microbiota composition that depended on the initial microbiota profile, specifically the presence or absence of Prevotella spp. as a major component of the microbiota. Our data therefore suggest that initial profiling of individuals through gut microbiota analysis should be considered important when contemplating nutritional interventions that rely on prebiotics. Clinical trial registration number: NCT02693782 . Registered 29 February 2016 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02693782?term=NCT02693782&rank=1

中文翻译：

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老年志愿者肠道微生物群中普雷沃氏菌属的相对丰度决定了个体对膳食补充剂麦麸阿拉伯木聚糖寡糖的反应。


人类结肠中栖息着密集的微生物群落，其物种组成和新陈代谢与健康和疾病有关。结肠细菌的主要能量来源是膳食多糖和寡糖。它们在调节肠道微生物组成和新陈代谢方面发挥着重要作用，进而影响健康结果。我们研究了麦麸阿拉伯木聚糖低聚糖 (AXOS) 和麦芽糖糊精补充剂对 60 岁以上健康成年人调节结肠微生物群和代谢物组成的影响。男性和女性志愿者（n = 21，平均 BMI 25.2 ± 0.7 kg） /m2）参加了双盲、交叉补充研究。收集粪便样本用于分析微生物群、短链脂肪酸水平和钙卫蛋白。收集血样以测量葡萄糖、胆固醇和甘油三酯水平。这些标记物和钙卫蛋白水平都没有因补充剂而发生变化。志愿者对这两种补充剂的耐受性良好。对整个志愿者队列的微生物群分析显示，补充 AXOS 后，粪便中双歧杆菌的丰度比例显着增加 (P ≤ 0.01)，但麦芽糖糊精则没有。其他做出反应的细菌类群存在相当大的个体间差异，志愿者有明确的分层，为普雷沃氏菌+（n = 8；> 0.1% 比例丰度）或普雷沃氏菌-负（n = 13；≤0.1% 比例丰度）丰度）基于基线样本概况的受试者。粪便双歧杆菌 (P ≤ 0.01) 和普雷沃氏菌 (P ≤ 0.01) 的比例丰度显着增加。01）在补充 AXOS 期间普雷沃氏菌+志愿者中，普雷沃氏菌和拟杆菌的相对丰度呈反比关系。 26 个 OTU（包括双歧杆菌和 Anaerostipes hadrus）的比例丰度在普雷沃氏菌阳性个体和普雷沃氏菌阴性个体的基线样本之间存在显着差异。麦麸 AXOS 补充剂具有双歧杆菌作用，会导致人体肠道微生物群组成发生变化，这取决于最初的微生物群分布，特别是普雷沃菌属的存在或不存在。作为微生物群的主要组成部分。因此，我们的数据表明，在考虑依赖益生元的营养干预措施时，通过肠道微生物群分析对个体进行初步分析应该被认为很重要。临床试验注册号：NCT02693782。 2016 年 2 月 29 日注册 - 追溯注册，https://clinicaltrials.gov/ct2/show/NCT02693782?术语=NCT02693782&排名=1