Diet influences the composition and diversity of mucosa-associated microbiota along the longitudinal axis of the pig gastrointestinal tract.. Swine mucosa-associated gut microbiota

Mucosa-associated microbial populations of the gastrointestinal tract occupy a unique position allowing intimate contact with host epithelial cells lining the gastrointestinal tract. This proximity gives these populations a much higher potential, than the luminal microbiota, in exerting effects on the host. The functional characteristics of the microbiota and the influences of host-derived factors shape the composition and activity of the mucosa-associated bacterial community. We have shown previously that inclusion of a low calorie sweetener, SUCRAM, routinely included in the diet of weaning piglets modulates the composition of luminal-residing gut microbiota, with implications of reducing weaning-related gastrointestinal disorders in pigs. In this study, we have used high throughput Illumina sequencing to characterise the mucosa-associated microbiota along the length of the intestinal tract of weaning piglets and determined the effect of SUCRAM supplementation on mucosa-associated populations. We show that there are clear distinctions in the composition of mucosa-associated microbiota between the small and large intestine, and that there are significant differences in the composition of mucosa-associated compared to luminal microbiota in pig caecum. Dietary supplementation with SUCRAM had a profound effect on mucosa-associated bacterial community structure along the entire length of the intestinal tract. Most notably, there was a substantial reduction in predominant Campylobacter populations proposing that SUCRAM supplementation of swine diet has potential for reducing meat contamination and promoting food safety.

胃肠道黏膜相关微生物群落（mucosa-associated microbial populations）处于独特的生态位，可与胃肠道内衬的宿主上皮细胞形成紧密接触。这种近距离接触使得此类群落相较于管腔微生物群（luminal microbiota），对宿主发挥调控作用的潜力显著更高。微生物群的功能特性与宿主来源因子的共同作用，塑造了黏膜相关细菌群落的组成与活性状态。我们此前的研究证实，在断奶仔猪日粮中常规添加的低热量甜味剂SUCRAM，可调控肠道管腔定植微生物群的组成，具有减轻仔猪断奶相关胃肠道病症的潜在作用。本研究采用高通量Illumina测序（high throughput Illumina sequencing）技术，对断奶仔猪全肠道各区段的黏膜相关微生物群落进行了表征，并探究了SUCRAM补充干预对黏膜相关微生物群落的影响。研究结果显示，小肠与大肠的黏膜相关微生物群落组成存在显著差异；且相较于管腔微生物群，仔猪盲肠内的黏膜相关微生物群组成亦存在显著差异。日粮添加SUCRAM对全肠道各段的黏膜相关细菌群落结构均具有显著调控作用。其中最为突出的是，优势弯曲杆菌属（Campylobacter）种群丰度大幅降低，这表明在猪日粮中添加SUCRAM，或可降低肉品污染风险并提升食品安全水平。