AUTHOR=Shen Hong , Lu Zhongyan , Chen Zhan , Wu Yufeng , Shen Zanming 

TITLE=Rapid Fermentable Substance Modulates Interactions between Ruminal Commensals and Toll-Like Receptors in Promotion of Immune Tolerance of Goat Rumen

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01812

DOI=10.3389/fmicb.2016.01812

ISSN=1664-302X

ABSTRACT=<p>Whether dietary non-fiber carbohydrate (NFC), a rapid fermentable substance, affects immune homeostasis of rumen through the modulation of interactions of ruminal microbiota and epithelial toll-like receptors (<italic>TLRs</italic>) remains unclear. A combination of 16S rRNA amplicon sequencing and quantitative PCRs was applied to study the synergetic responses of ruminal microbiota and epithelial <italic>TLRs</italic> to the dietary NFC switch from 15 to 31% in the goat model. The results showed that the 31% NFC diet caused the radical increases on the richness and diversity of rumen microbiota. The phylum Verrucomicrobia was most significantly expanded, whereas opportunistic pathogens, namely <italic>Rikenella</italic>, <italic>Anaeroplasma</italic>, and <italic>Olsenella</italic>, were significantly decreased. In rumen epithelium, the significantly increased expressions of <italic>TLR1</italic>, <italic>6</italic>, <italic>10</italic> were associated with the significantly decreased expressions of pro-inflammatory cytokines interleukin-1beta (<italic>IL-1ß</italic>), <italic>IL-6</italic>, and anti-inflammatory cytokine <italic>IL-10</italic>. Constrained correlation analysis indicated that the increased abundance of commensal bacteria in Verrucomicrobia subdivision 5 contributed to the upregulation of <italic>TLR10</italic> expression. Finally, the significantly increased concentrations of rumen short-chain fatty acids (SCFAs), coupled with the significantly upregulated expressions of epithelial genes related to SCFA absorption were observed in goats fed with 31% NFC diet. Thus, the NFC-induced expansion of rumen microbiota promoted epithelium tolerance by enhancement of the intensity of <italic>TLR10</italic> signaling. The newly established equilibrium benefited to the transport of ruminal energy substances into the blood.</p>