Background: Environmental enteropathy, linked to undernutrition and chronic infections, affects the physical and mental growth of children in developing areas worldwide. Key to understanding how these factors combine to shape developmental outcomes is first understanding the effects of nutritional deficiencies on the mammalian system, including the effect on the gut microbiota.
Objective: We dissect the nutritional components of environmental enteropathy by analyzing the specific metabolic and gut microbiota changes that occur in weaned mouse models of zinc or protein deficiency as compared to well-nourished controls.
Design: Using a 1H NMR spectroscopy-based metabolic profiling approach with matching 16S microbiota analyses, the metabolic consequences and specific effects on the fecal microbiota of protein and zinc deficiency were probed independently in a murine model.
Results: We find considerable shifts within the intestinal microbiota 14-24d post-weaning in mice maintained on a normal diet (including increases in Proteobacteria and striking decreases in Bacterioidetes). While the zinc deficient microbiota were comparable to the age-matched well-nourished profile, the protein-restricted microbiota remained closer in composition to the weaned enterotype with retention of Bacteroidetes. Striking increases in Verrucomicrobia (predominantly Akkermansia muciniphila) were observed in both well-nourished and protein-deficient mice 14d post-weaning. We find that protein malnutrition impairs growth and has major metabolic consequences (much more than zinc deficiency) that include altered energy, polyamine and purine/pyrimidine metabolism. Consistent with major changes in the gut microbiota, reductions in microbial proteolysis and increases in microbial dietary choline processing were observed.