Z (Zhuang) Liu MSc

Effect of dietary components on microbiota composition and activity: towards microbiota stratification

Background

Gut microbes and their activity are crucial factors for our well-being. It has become evident that there are considerable differences in individual composition of the microbiota, and first attempts towards stratification led to the definition of three main consensus profiles, the so-called enterotypes (Arumugam et al., 2011). Stratification of microbiota according to composition, such as by enterotypes, showed that those different microbial steady states were strongly associated with long-term dietary habits (Wu et al., 2011), and certain enterotypes have shown higher frequencies in Irritable Bowel Syndrome (IBS ) patients or obese subjects with higher risk for metabolic syndrome (Rajilic – Stojanovic et al., 2011; LeChatelier et al., 2013). Although the presence of enterotypes has been disputed (Knights et al., 2014), it is possible that there may be specific microbial stratifications or some key signature microbes involved in the generation of particular metabolites, which in turn might be related to host health. There are multiple studies that reported that healthy subjects and patients differ in microbiota composition. However, a general consensus or causal associations with host parameters are largely lacking.

Hypothesis

We hypothesize that microbiota activity profiles are associated with health and that the success rate of changing activity profiles by dietary and/or prebiotic/probiotic interventions is dependent on the initial microbiota composition profile. Therefore we hypothesize that stratification of subjects according to microbiota composition is thus crucial to increase successful responsiveness towards different dietary and or probiotic/prebiotic interventions.

Objectives

1. To study whether specific microbiota composition profiles or specific metabolites/metabolite profiles are correlated to specific health parameters.

2. To investigate the impact of different dietary components and formulations on metabolite profiles generated by microbiota stratified according to composition.

3. To investigate whether stratification of subjects according to microbiota composition and subsequent targeted intervention would do some help to predict host responsiveness.

To address our hypotheses, we will combine detailed literature research, database screening, in vitro fermentation studies, and dietary intervention studies.