Measuring the impact of diet-microbe interactions on host health

Obesity and overweight incidence have dramatically increased worldwide, and they constitute the leading cause of chronic pathologies. Modern obesogenic diet lacks of fruit/vegetable consumption, in favor of highly processed foods, rich in simple sugars, saturated and trans-saturated fats. The impact of dietary compounds on human host metabolism is strongly influenced by the human gut microbiota (GM), which transform fiber and plant secondary metabolites, with production of short chain fatty acids and small phenolics, modulation of bile acid profiles, which together exert systemic in vivo activity. My work employes the following in vivo and in vitro approaches to investigate GM response to foods and to correlate GM populations with dietary metabolites relevant for the risk of metabolic syndrome and type 2 diabetes (T2D): 1. Study of the impact of an inflammatory and diabetogenic diet enriched in advanced glycation end-products (AGEs) in modulating the GM of mice; 2. In vitro faecal fermentation of a Trentino ecotype of Brassica oleracea, by characterization of GM composition and metabolites. GM is studied through 16S rRNA sequencing and taxonomic analysis, as well as metabolite profiling. Preliminary results have shown a correlation between diet and GM, with AGEs feeding appearing to significantly lower Lactobacillus, Prevotella, and Ruminococcus (Ruminococcaceae family) and rise Parabacteroides, Ruminococcus (Lachnospiraceae family), Allobaculum and Mucispirillum levels, in a way that resembles what was previously observed in mice in association with T2D and inflammation. Faecal fermentation of Broccolo showed to modulate GM composition over time: this will be linked to measured metabolites in fermentation supernatants.