High-Protein Diets Effect on Metabolic Profiles, Gut Microbiota and Inflammation Markers in a Murine Model

Abstract

Dietary food is a key factor that limits the composition of microbial communities in the gut. Extreme diets cause a gut microbiota dysbiosis, modifying immunological markers and being able to produce inflammation in diverse organs. Specialized diets for losing weight and gaining muscle mass, and a raising economical support to obtain meat products in the market have doubled the recommended protein consumption amongst the population. The aim of this work was to elucidate the effects over metabolic profiles, gut microbial communities and inflammation markers that a high-protein diet, vegetal- and animal- based, can cause in a murine model. 27 male mice of 17 weeks of life (Mus musculus C57BL/6) divided in 3 groups: 1) vegetal, 2) animal and 3) standard were fed ad libitum with a high-protein diet (25- 30 %) for 7.5 weeks, following the directions of CICUAL and the Vivarium of Tecnológico de Monterrey. Mice were weighted every week. After the experimental phase, epididymal fat was measured in every group. Also, cecum samples were analysed by qPCR to evaluate the changes in gut microbiota (total bacteria, Bifidobacterium, Lactobacillus, Enterobacteria). Blood samples were collected to obtain serum, and the inflammation markers TNF-α, IL-6 and IL-10 and were analysed by Milliplex® MAP technology and the CRP by ELISA. The statistical tool Minitab® was used to process the results through ANOVA and transforming the data when necessary. Vegetal-based protein diet individuals had more epididymal fat than the rest of the groups. Moreover, they showed a higher IL-10 production as well as the CG. Nevertheless, microbial communities were compromised in the animal-based protein diet, showing signs of dysbiosis, although not presenting excessive production of inflammatory cytokines. Therefore, metabolism of a protein excess with similar amino acid profile may have negative consequences in amino acid utilization and formation of by-products, gut microbiota profiles and inflammation in gut depending on the protein source.