Xylanase modulates ileal microbiota in pigs

The experimental objective was to characterize the impact of insoluble corn-based fiber, xylanase, and an arabinoxylan-oligosaccharide on ileal digesta and mucosa microbiome of pigs. We hypothesized that the addition of xylanase or AXOS would modulate intestinal microbial communities that support fiber degradation (stimbiotic mechanism) or would be selectively utilized by communities that are known to confer a health benefit (prebiotic mechanism). Three replicates of 20 gilts were blocked by initial body weight, individually-housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF), a 30% corn bran high-fiber control (HF), HF+100 mg/kg xylanase (HF+XY), and HF+50 mg/kg arabinoxylan oligosaccharide (HF+AX). Gilts were fed their respective treatments for 46-days. On day 46, pigs were euthanized and ileal digesta and mucosa were collected. The V4 region of the 16S rDNA was amplified and sequenced.

本实验旨在表征不溶性玉米基纤维、木聚糖酶以及阿拉伯木聚糖寡糖（arabinoxylan-oligosaccharide，AXOS）对猪回肠食糜与黏膜微生物组的影响。我们提出如下假说：添加木聚糖酶或AXOS，可通过两种机制调控肠道微生物群落——其一为促生素（stimbiotic）机制，即促进可辅助纤维降解的菌群；其二为益生元（prebiotic）机制，即被已知可赋予宿主健康益处的菌群选择性利用。本实验按初始体重对20头后备母猪进行区组设计，设置3个重复组，所有受试猪单栏饲养，并随机分配至4种日粮处理组：低纤维对照组（LF）、含30%玉米麸皮的高纤维对照组（HF）、HF+100 mg/kg木聚糖酶组（HF+XY）、HF+50 mg/kg阿拉伯木聚糖寡糖组（HF+AX）。受试母猪按对应日粮连续饲喂46天。于第46天对猪只实施安乐死，采集回肠食糜与黏膜样本。随后对16S核糖体DNA（16S rDNA）的V4区域进行扩增并测序。