Deprivation of dietary fiber in specific-pathogen-free mice promotes susceptibility to the intestinal mucosal pathogen Citrobacter rodentium

Abstract

The change of dietary habits in Western societies, including reduced consumption of fiber, is linked to alterations in gut microbial ecology. Nevertheless, mechanistic connections between diet-induced microbiota changes that affect colonization resistance and enteric pathogen susceptibility are still emerging. We sought to investigate how a diet devoid of soluble plant fibers impacts the structure and function of a conventional gut microbiota in specific-pathogen-free (SPF) mice and how such changes alter susceptibility to a rodent enteric pathogen. We show that absence of dietary fiber intake leads to shifts in the abundances of specific taxa, microbiome-mediated erosion of the colonic mucus barrier, a reduction of intestinal barrier-promoting short-chain fatty acids, and increases in markers of mucosal barrier integrity disruption. Importantly, our results highlight that these low fiber diet-induced changes in the gut microbial ecology collectively contribute to a lethal colitis by the mucosal pathogen Citrobacter rodentium, which is used as a mouse model for enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively). Our study indicates that modern, low-fiber Western diets might make individuals more prone to infection by enteric pathogens via the disruption of mucosal barrier integrity by diet-driven changes in the gut microbiota, illustrating possible implications for EPEC and EHEC infections.

The dietary fiber guar gum ameliorates experimental autoimmune encephalomyelitis via attenuated Th1 activation and differentiation

“…To test the hypothesis that autoimmune neuroinflammation is responsive to dietary fiber intake, we exposed cohorts of mice to standard 5% cellulose (control) fiber diet, diet entirely lacking dietary fiber (0% fiber), or diets enriched (30%) with a single fiber source of resistant starch, inulin, pectin, or guar gum (macronutrient information in Table S1) for two weeks prior to EAE induction (Figure 1A). In contrast to findings in other inflammatory disease contexts that showed increased inflammation with fiber-deficient diets (Desai et al, 2016; Neumann et al, 2021; Shen et al, 2021; Tan et al, 2016; Trompette et al, 2014), but consistent with previous findings in EAE (Mizuno et al, 2017), a zero-fiber diet did not significantly affect EAE onset, incidence, or severity (Figure 1B-D).…”

Lactobacillus murinus alleviate intestinal ischemia/reperfusion injury through promoting the release of interleukin-10 from M2 macrophages via Toll-like receptor 2 signaling

“…Gut microbiota is a complex ecosystem susceptible to the surrounding environment and diet [50]. We have previously confirmed that intestinal I/R induces significant intestinal flora disorders and indicated that intestinal microbial metabolites play an important regulatory role in intestinal I/R injury [40,51].…”

Dietary fibre deprivation and bacterial curli exposure shift gut microbiome and exacerbate Parkinson's disease-like pathologies in an alpha-synuclein-overexpressing mouse

“…There is a great body of evidence on the impact of diet on microbial gut health and how it can influence the course of a disease. In vivo studies where rodents were fed a fibre deprived diet saw rapid shifts in microbial gut populations(Schroeder et al 2018; Desai et al 2016; Neumann et al 2021; Riva et al 2019). Accordingly our data showed decreased diversity, increased Firmicutes / Bacteriodetes ratios and altered abundance of many taxa.…”