Early colonizing Esche richia coli elicits remodeling of rat colonic epithelium shifting toward a new homeostatic state

Abstract

We investigated the effects of early colonizing bacteria on the colonic epithelium. We isolated dominant bacteria, Escherichia coli, Enterococcus faecalis, Lactobacillus intestinalis, Clostridium innocuum and a novel Fusobacterium spp., from the intestinal contents of conventional suckling rats and transferred them in different combinations into germfree (GF) adult rats. Animals were investigated after various times up to 21 days. Proliferative cell markers (Ki67, proliferating cell nuclear antigen, phospho-histone H3, cyclin A) were higher in rats monocolonized with E. coli than in GF at all time points, but not in rats monocolonized with E. faecalis. The mucin content of goblet cells declined shortly after E. coli administration whereas the mucus layer doubled in thickness. Fluorescence in situ hybridization analyses revealed that E. coli resides in this mucus layer. The epithelial mucin content progressively returned to baseline, following an increase in KLF4 and in the cell cycle arrest-related proteins p21 CIP1 and p27 KIP1. Markers of colonic differentiated cells involved in electrolyte (carbonic anhydrase II and slc26A3) and water (aquaglyceroporin3 (aqp3)) transport, and secretory responses to carbachol were modulated after E. coli inoculation suggesting that ion transport dynamics were also affected. The colonic responses to simplified microbiotas differed substantially according to whether or not E. coli was combined with the other four bacteria. Thus, proliferation markers increased substantially when E. coli was in the mix, but very much less when it was absent. This work demonstrates that a pioneer strain of E. coli elicits sequential epithelial remodeling affecting the structure, mucus layer and ionic movements and suggests this can result in a microbiota-compliant state.

Post‐natal co‐development of the microbiota and gut barrier function follows different paths in the small and large intestine in piglets

“…47 However, whether members of the Peptostreptococcaceae and Micrococcacea families interact with the maturating mucosa and why such specific regional interactions were observed deserve further investigations. The role of Escherischia coli early colonization in gut mucosa modeling has been already studied.…”

Extract of the Microalga Nitzschia laevis Prevents High‐Fat‐Diet‐Induced Obesity in Mice by Modulating the Composition of Gut Microbiota

“…In addition, functional classes such as [K] Transcription and [G] Carbohydrate transport and metabolism, were also retained by NLE treatment (Figure ), although the relationship between these functional changes and anti‐obesity bioactivity has not been characterized . GM can also help strengthen mucosal defence by stimulating epithelial renewal and immune maturation and increasing intestinal impermeability . Consistently, our results revealed that NLE treatment upregulated the expression of occludin, which was greatly reduced by HFD, and the expression of ZO‐1 (Figure ), to protect the gut barrier.…”

The microbiota shifts the iron sensing of intestinal cells

“…The implantation of a particular microbiota has been shown to shape all genuine intestinal functions, including absorptive, protective, and secretory functions (19). The intestine undergoes functional maturation during conventionalization, with a pattern of responsiveness dependent on the kinetics of colonization and the bacteria involved (20)(21)(22)(23)(24)(25)(26)(27). Gnotobiotic rodents represent one of the useful tools for deciphering the complex mechanisms of dietary iron on gut microbiota and health (28).…”