1. Personalized gut microbiota-targeted dietary intervention for type 2 diabetes.
Keywords: Nutrition, glycemic control, bacterial fermentation
Manipulating the host diet, specifically the availability of the amount and type of carbohydrate and protein for bacterial fermentation, is a key strategy to alter the gut microbial profile and functions. Conventional "one-size-fits-all" standardized microbiota-targeted dietary interventions are unlikely to confer universal benefits. The human gut microbiota is highly variable across individuals, with genetic, demographic and environmental factors they key determinants that shape our gut microbial composition. Each individual, therefore, has his/her own unique baseline microbiota with different carbohydrate fermentation capacities prior to interventions. What further complicates treatment efficacy is how each person’s gut microbiota respond to a particular intervention. Accordingly, it is only logical to tailor microbiota-targeted interventions based on each individual's gut ecosystem parameters, and make adjustments during the interventions depending on initial responses to maximize treatment efficacy
2. In vitro fermentation as a tool for personalized dietary fiber supplementation.
Keywords: Dietary fiber supplementation, in vitro fermentation
Gut bacteria ferment carbohydrates to generate short-chain fatty acids (SCFAs), which directly benefit the host by providing energy substrates to colonocytes and functioning as signaling molecules that modulate immune response and appetite control. A commonly used strategy to promote SCFA production is to increase the availability of fermentable carbohydrates in the colon via dietary fiber supplementation. Clinical trials using high dietary fiber diets have been reported to confer health benefits, particularly in glycemic control and weight management, but with vastly different treatment response across individuals.
The capacity for fermenting carbohydrates into SCFAs is a genetic trait shared by hundreds of gut bacterial species. Gut microbial profile is unique in each person, implying that we may vary in capacities for utilizing different types of dietary fiber. Being able to prescribe dietary fiber supplementation based on one’s fermenting capacity will be critical to improve treatment efficacy. We propose to use in vitro fermentation with human fecal inoculum as a tool to inform on which dietary fiber subtypes will most likely be utilized by the gut bacteria when consumed in the diet.