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Linkages between Epithelial Microbiota and Host Transcriptome in the Ileum during High-Grain Challenges: Implications for Gut Homeostasis in Goats
journal contribution
posted on 2018-12-06, 00:00 authored by Jinzhen Jiao, Xiaoli Zhang, Min Wang, Chuanshe Zhou, Qiongxian Yan, Zhiliang TanA high-grain
(HG) diet can result in ruminal subacute acidosis,
which is detrimental to gut health and can lead to decreased productivity.
This study investigated the ileal epithelial microbiota and its relationship
with host epithelial function in goats fed a HG diet (concentrate/hay,
90:10) and a control diet (concentrate/hay, 55:45), aiming to elucidate
the mechanisms involved in ileal adaptation to subacute acidosis.
The HG challenge increased the ileal volatile fatty acid concentration
(p = 0.030) and altered the ileal epithelial microbiota
by increasing (FDR < 0.05) relative abundances of active carbohydrate
and protein degraders Synergistetes, Prevotella, Fibrobacter, Clostridium, Treponema, and unclassified Ruminococcaceae
by 20.1-, 6.3-, 16.8-, 8.5-, 19.9-, and 7.1-fold, respectively. However,
the HG diet tended to reduce (FDR < 0.10) the relative abundance
of Candidatus Arthromitus (38.8 ±
36.1 versus 2.1 ± 3.1). Microbial functional potentials inferred
using PICRUSt indicated that the HG challenge elevated abundances
of pathways associated with metabolism of amino acid, glycan, cofactors,
and vitamins, whereras it decreased pathways associated with signal
transduction, xenobiotic biodegradation, and metabolism. Additionally,
in the ileal epithelium of HG goats, transcriptome analysis identified
the increment (FDR < 0.10) of candidate genes involved in metabolism
of carbohydrates, lipids, proteins, vitamins, and the proinflammatory
cytokine pathway, while downregulating genes encoding antimicrobials
and complements (FDR < 0.05). Collectively, the HG challenge shifted
the structure and functional potentials of the ileal microbial community
and affected the host responses in the ileum of goats toward increased
metabolic activities of macro- and micronutrients, together with an
increased risk of gut inflammation.