Dietary xylo-oligosaccharide supplementation alters gut microbial composition and activity in pigs according to age and dose. Dietary xylo-oligosaccharide supplementation alters gut microbial composition and activity in pigs according to age and dose

This study explored the effect of dietary xylo-oligosaccharides (XOS) supplementation on the gut microbial composition and activity in pigs with different ages. Eighty pigs with an average body weight (BW) of 30 kg were randomly divided into eight groups: A control group, a group that received antibiotic treatment, and six groups fed diets supplemented with 100, 250, and 500 g/t XOS, of which three groups were in the growing period (GP, 30–65 kg BW) and three groups in the growing and fattening period (GFP, 30–100 kg BW). At the end of the experiment, the intestinal contents were sampled for analyses of gut microbiota and bacterial metabolites including short-chain fatty acids (SCFAs) and bioamines. The results showed that 100 g/t XOS supplementation during the GFP significantly reduced the relative abundances of presumably pathogenic bacteria (Proteobacteria and Citrobacter), but enhanced the relative abundances of likely beneficial bacteria (Firmicutes and Lactobacillus). However, XOS supplementation during the GP showed little effect on the gut microbiota when pigs were killed at 100 kg BW. Meanwhile, 100 g/t XOS supplementation during the GFP decreased the level of 1,7-heptane diamine and increased the acetic acid, straight-chain fatty acids, and total SCFAs concentrations in the intestinal contents. Statistical analysis showed that both the dose and exposure time to XOS supplementation affected the microbial communities. In summary, 100 g/t XOS supplementation during the GFP modified the gut microbiota composition and metabolic activity. Possible consequences of such changes for the host are discussed.

本研究探讨了日粮添加低聚木糖（xylo-oligosaccharides, XOS）对不同日龄猪肠道微生物组成与活性的影响。试验选取80头平均体重（body weight, BW）为30kg的猪只，随机分为8组：对照组、抗生素处理组，以及6个分别饲喂添加100、250、500g/t XOS日粮的组别；其中3组处于生长阶段（GP，体重30~65kg BW），另外3组处于生长育肥阶段（GFP，体重30~100kg BW）。试验结束时，采集肠道内容物以分析肠道菌群及短链脂肪酸（short-chain fatty acids, SCFAs）、生物胺等细菌代谢产物。结果显示，在生长育肥阶段添加100g/t XOS可显著降低潜在致病菌（变形菌门与柠檬酸杆菌属）的相对丰度，同时提升有益菌（厚壁菌门与乳杆菌属）的相对丰度。然而，在生长阶段添加XOS的组别，当猪只体重达到100kg时屠宰，其肠道菌群几乎未受影响。与此同时，生长育肥阶段添加100g/t XOS可降低肠道内容物中1,7-庚二胺的水平，并提升乙酸、直链脂肪酸及总短链脂肪酸的浓度。统计分析表明，XOS的添加剂量与暴露时长均会影响微生物群落组成。综上，在生长育肥阶段添加100g/t XOS可改变肠道菌群组成与代谢活性，本文还探讨了此类变化对宿主的潜在影响。