The Impact of Host Genotype, Intestinal Sites and Probiotics Supplementation on the Gut Microbiota Composition and Diversity in Sheep

Abstract

Three sampling strategies with a 16s rRNA high-throughput sequencing and gene expression assay (by RT-PCR) were designed, to better understand the host and probiotics effect on gut microbiota in sheep. Sampling: (1) colon contents and back-fat tissues from small-tailed Han sheep (SHS), big-tailed Hulun Buir sheep (BHBS), and short-tailed Steppe sheep (SHBS) (n = 12, 14, 12); (2) jejunum, cecum and colon contents, and feces from Tan sheep (TS, n = 6); (3) feces from TS at 4 time points (nonfeeding, 30 and 60 feeding days, and stop feeding 30 days) with probiotics supplementation (n = 7). The results indicated SHS had the highest Firmicutes abundance, the thinnest back-fat, and the lowest expression of C/EBPβ, C/EBPδ, ATGL, CFD, and SREBP1. Some bacteria orders and families could be potential biomarkers for sheep breeds with a distinct distribution of bacterial abundance, implying the host genotype is predominant in shaping unique microbiota under a shared environment. The microbiota diversity and Bifidobacterial populations significantly changed after 60 days of feeding but restored to its initial state, with mostly colonies, after 30 days ceased. The microbiota composition was greatly different between the small and large intestines, but somewhat different between the large intestine and feces; feces may be reliable for studying large intestinal microbiota in ruminants.

Lower blood lipid level from the administration of plant tannins via altering the gut microbiota diversity and structure

“…Through analysis, neither the jejunal nor colonic B/F value, ratio of phyla Bacteroidetes to Firmicutes, was directly correlated to the blood lipids in the experimental sheep, although their relative ratio has been used to demonstrate obesity effects in sheep and mice. 24,42 The divergence from their usual relationship in this study might be due to a shift in the effect of TA and GSPE, which diminished the concentration of blood lipids and which was more connected with altering the abundances of some critical bacteria genera. This result suggested that TA and GSPE have different influences on varied bacteria at various sites because of their different degradation along the digestive tract.…”

“…16S rRNA sequencing data were processed by QIIME1.9.1, USEARCH61, and UCLUST with 97% similarity, Ribosomal Database Project (RDP), and Greengenes (13_8 release) database to generate an OTU table, as we previously described. 24 Then the alpha diversity (Shannon diversity and Chao1 index) and beta diversity (weighted UniFrac distance) were calculated based on the above OTU table. While the functional potential of the gut microbiota community was analyzed by PICRUSt relying on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database.…”