The Interaction Between Protein Intake, Gut Microbiota and Type 2 Diabetes in Subjects With Different Ethnic Backgrounds

Context and justification: There is growing evidence that the gut microbiota is a key element in the pathophysiology of cardio-metabolic diseases (CMD) such as Type 2 Diabetes (T2D). One hypothesis is that gut-derived metabolites (from diet) have an important role in the host metabolism. Preliminary results show that imidazole propionate (ImP), a degradation product of the essential amino acid histidine, is produced by the gut microbiota of T2D patients, but not healthy subjects. The gut microbiota itself is strongly influenced by diet and ethnicity. However, most dietary intervention studies have focused on the role of fiber intake and the effect of dietary protein on the gut microbiota composition and metabolite production is not well known. Our hypothesis is that, depending on the baseline gut microbiome composition, a diminution in protein intake could decrease the microbial production of metabolites such as ImP and improve the metabolism of the host. We also hypothesize that the effects of such an intervention could depend the ethnic background. Objective: To study the effects of a high protein (HP) vs a low protein (LP) diet on gut microbiota composition and production of pro-diabetic metabolites in type 2 diabetes (T2D) patients from Caucasian and Caribbean ethnicity depending on baseline metagenomics richness. Study design: Randomized controlled three months dietary intervention study Study Population: T2D patients from Caucasian (N=80) and Caribbean (N=40) background who are on a stable dose of metformin and do not use insulin or proton-pump inhibitors. Intervention: Subjects will be randomized to either a high protein (HP) or low protein (LP) diet for three months. Individuals of Caucasian ethnicity, will also be stratified according to either a high or low gut microbiota gene richness. All subjects will receive pre-cooked meals 6 days per week and daily food packages. Subjects are required to keep food diaries three days a week and will also have