Date Published: February 18, 2019
Publisher: Springer Berlin Heidelberg
Author(s): Huan Li, Huawei Li, Peifeng Xie, Zhihua Li, Yulong Yin, Francois Blachier, Xiangfeng Kong.
Gut microbiota positively contribute to livestock nutrition and metabolism. The manipulation of these microbes may improve animal health. Some feed additives improve livestock health and metabolism by regulating gut microbiota composition and activity. We fed hybrid pigs diets supplemented with 0% (control), 5% (treat 1), 10% (treat 2), or 15% (treat 3) fermented Mao-tai lees (FML) for 90 days. Short-chain fatty acids (SCFAs), bioamines, and microbial communities found in colonic contents were analyzed to investigate microbiota composition and metabolic profiles. Concentrations of straight-chain fatty acids (e.g., acetate, propionate, and butyrate) and tyramine increased with FML supplementation content. Contrary to the minor effects of 5% and 10% FML on gut microbiota, 15% FML influenced beta diversity (Jaccard or Bray–Curtis dissimilarity) but not alpha diversity (number of operational taxonomic units and Shannon diversity) of pig gut microbial communities compared to the control group. Notably, 15% FML animals were characterized by a higher abundance of potentially beneficial bacteria (Lactobacillus and Akkermansia) but lower abundances of potential pathogens (Escherichia). Numerous genes associated with metabolism (e.g., starch, sucrose, and sulfur-compounds metabolism) showed a higher relative abundance in the 15% FML than in the control group. Additionally, most Phascolarctobacterium, Treponema, Prevotella, and Faecalibacterium bacterial markers in the 15% FML group were positively correlated with straight-chain fatty acid concentrations, suggesting that these bacteria are likely associated with SCFA production. Taken together, our findings demonstrate the beneficial effects of 15% FML on fermentation of undigested compounds and gut microbiota composition in the colon. Thus, 15% FML supplementation in pig feed may possibly represent a way to optimize pig colon health for livestock farming.
Healthy livestock farming technologies and management practices are a central concern in animal farming industry, which must provide high-quality meat products to safely meet human consumption requirements. In particular, pigs are one of the most important economic livestock species in numerous countries. Pigs represent the largest livestock product in China, with great commercial and economic values worldwide (Bai et al. 2014; Sun and Jia 2015; Yu and Abler 2014). However, intensive or large-scale livestock farming causes various problems such as serious feed resource shortages and grain competition between humans and livestock (Ilea 2009). In addition, the utilization of antibiotics in livestock husbandry potentially poses a threat to livestock health, and it could lead to environmental pollution as well as a decline in animal immunity, gut microbiota disorders, and an increased risk of the spread of antibiotic-resistant bacteria genes in the environment (Baquero et al. 2008; Wu et al. 2010; Zhao et al. 2018). Residues of antibiotics in livestock products are likely harmful to human health (Marshall and Levy 2011). However, the restricted use of antibiotics in feed used in livestock farming may increase disease rates in animals and decrease amounts of global products. Therefore, it is imperative to develop safe and effective feed additives that could replace antibiotics, thus improving livestock health and products. Recently, studies focused on replacing antibiotics in livestock husbandry have examined the effects of probiotics, prebiotics, synbiotics, and other dietary additives on livestock (Abudabos et al. 2017; Markowiak and Slizewska 2018; Marshall and Levy 2011). Moreover, these studies have aroused the interests of scientists globally, since these newly developed feed supplements were found to improve livestock health and growth (Markowiak and Slizewska 2018).
In the field of animal nutrition, the development of new potential prebiotics in animal husbandry industries is of current interest. Recently, high-throughput sequencing of 16S rRNA gene amplicons has been used to investigate potential beneficial effects of various feed additives (e.g., xylo-oligosaccharides and yeast cultures) on the gut microbial communities of farmed animals (Liu et al. 2018; Pourabedin et al. 2015). However, relatively few studies focused on the effects of liquor lees on the composition and function of livestock gut microbiota. This study is the first to report the influence of FML on pig gut microbiota and metabolic profiles. Our results indicated that dietary supplementation with 15% FML significantly influenced gut microbial community structure and bacterial metabolite concentrations in pigs, and those abundant OTUs in the 15% FML group were positively associated with the fermentation of dietary fiber. Moreover, 15% FML improved the relative abundance of potential beneficial bacteria and decreased the abundance of pathogens. These results greatly enhanced our understanding of the potential beneficial effects of FML on pigs.