This year the INRA team (French National Institute for Agriculural Research) has presented in various symposiums in France to share results obtained in the MyNewGut human study. This study aimed at evaluating the effects of the quantity and quality of protein intake on the microbiota composition, feces and urinary bacterial metabolite composition, and consequences for the rectal mucosa.
- INRA/Rowett Joint Symposium (Clermont-Ferrand) - June 20th - 23rd 2016
- French-speaking days of Hepato-Gastroenterology and Digestive Oncology (Paris) - March 20th 2016
- Symposium on Digestive Epithelial Cells (Lille) - March 10th - 11th 2016
- French-speaking days of Nutrition (Marseille) - December 9th - 11th 2015
The results of their randomized, double-blind, parallel-design performed in 38 overweight individuals showed that after 3 weeks nutritional intervention, the overweight volunteers which consumed the isocaloric high-protein diet containing either protein from animal (casein) or plant (soy) origin display specific metabolic signature in feces characterized by decreased concentration of the beneficial compound butyrate, and increased amino acid-derived bacterial metabolite concentrations with different profiles according to the protein sources, indicating the importance of the nature of the protein for the regulation of the microbiota metabolism. The microbiota composition was however little affected by the high-protein diet. Much interestingly, the casein and soy protein markedly and differently, according to the protein source, impacted in rectal biopsies the expression of genes playing key roles in mucosal homeostasis processes such as epithelial renewal. Thus, quantity and quality of alimentary intake are 2 important parameters for the regulation of the gut microbiota metabolite concentrations. These effects are associated with a regulation of crucial biological pathways in the rectal mucosa at the gene expression level, raising the view that high-protein diet, which are used for slimming purpose by millions of individuals around the world, should be considered with some caution as they might impact rectal epithelial homeostasis.