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bioRxiv · 10.1101/675918

In situ analysis of mucus residing bacterial community reveals an ecological niche key for gut microbiome stability

Abstract

Mucus associated bacterial communities are critical for determining disease pathology and promoting colonization resistance. Yet the key ecological properties of mucus resident communities remain poorly defined. Using an approach that combines in situ hybridization, laser microdissection and 16s rRNA sequencing of spatially distinct regions of the mouse gut lumen, we discovered that a dense microbial community resembling a biofilm is embedded in the mucus layer. The mucus associated biofilm-like community excluded bacteria belonging to phylum Proteobacteria. Additionally, it was significantly more diverse and consisted of bacterial species that were unique to it. By employing germ-free mice deficient in T and B lymphocytes we found that formation of biofilm-like structure was independent of adaptive immunity. Instead the integrity of biofilm-like community depended on Gram-positive commensals such as Clostridia. Additionally, biofilm-like community in the mucus lost fewer Clostridia and showed smaller bloom of Proteobacteria compared to the lumen upon antibiotic treatment. When subjected to time restricted feeding biofilm like structure significantly enhanced in size and showed enrichment of Clostridia. Taken together our work discloses that mucus associated biofilm-like community represent a specialized community that is structurally and compositionally distinct that excludes aerobic bacteria while enriching for anaerobic bacteria such as Clostridia, exhibits enhanced stability to antibiotic treatment and that can be modulated by dietary changes.

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BibTeXRIS

Duncan, K., Carey Ewend, K., vaishnava, s.. 2019-06-19. In situ analysis of mucus residing bacterial community reveals an ecological niche key for gut microbiome stability. https://doi.org/10.1101/675918

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