The effect of microbial colonization on the host proteome varies by gastrointestinal location

Abstract

Endogenous intestinal microbiota have wide-ranging and largely uncharacterized effects on host physiology. Here, we used reverse-phase liquid chromatography-coupled tandem mass spectrometry to define the mouse intestinal proteome in the stomach, jejunum, ileum, cecum and proximal colon under three colonization states: germ-free (GF), monocolonized with Bacteroides thetaiotaomicron and conventionally raised (CR). Our analysis revealed distinct proteomic abundance profiles along the gastrointestinal (GI) tract. Unsupervised clustering showed that host protein abundance primarily depended on GI location rather than colonization state and specific proteins and functions that defined these locations were identified by random forest classifications. K-means clustering of protein abundance across locations revealed substantial differences in host protein production between CR mice relative to GF and monocolonized mice. Finally, comparison with fecal proteomic data sets suggested that the identities of stool proteins are not biased to any region of the GI tract, but are substantially impacted by the microbiota in the distal colon.

Diet–microbiota interactions as moderators of human metabolism

“…The majority of studies in humans and mice rely on faecal samples, which provide some representation of what is occurring throughout the digestive tract; however, aspects of microbial communities and host responses that are specific to the small intestine might be obscured by faecal sampling 119,120 . For example, it could miss information on how the microbiota affects nutrient absorption in the small intestine through its impact on glucose transporters and bile acids, which are essential for the absorption of lipids and fat-soluble vitamins.…”

Developmental exposure to polychlorinated biphenyls (PCBs) in the maternal diet causes host-microbe defects in weanling offspring mice

“…In contrast, the antimicrobial peptide RegIIIg demonstrated similar effects in both the colon and ileum of DM mice, with increases in expression levels seen following PCB exposure. Recent studies have determined that region-specific differences exist in the microbiota composition and subsequent proteome analysis, which could contribute to changes in host responses (Lichtman et al, 2016). Given the change observed in RegIIIg expression, alterations in mucosa-associated bacteria would be of interest for future studies.…”

When Cultures Meet: The Landscape of “Social” Interactions between the Host and Its Indigenous Microbes

“…[52,53] However, microbial communities adapt to their physical environment and availability to nutrients. [60][61][62] Ultimately, and in line with the ambition to generate new treatment regimens for lifestylerelated diseases using microbial intervention, the impact of microbial biogeographical localization on host physiology and disease merits further studies. Gut microbial composition, in terms of aerobes and anaerobes, most likely also adapt to these differences.…”