Abundance of gut Prevotella at baseline and metabolic response to barley prebiotics.

We previously showed that short-term intervention with barley kernel bread (BKB) improved glucose tolerance. However, glucose tolerance was not improved in a subset of individuals (non-responders) who were characterized by a low Prevotella/Bacteroides ratio. The purpose of the present study was to investigate if the baseline Prevotella/Bacteroides ratio can be used to stratify metabolic responders and non-responders to barley dietary fiber (DF). Fecal samples were collected from 99 healthy humans with BMI < 28 kg/m The BKB intervention lowered the blood glucose responses to the breakfast independently of Prevotella/Bacteroides ratios (P < 0.01). However, independently of intervention, the HP group displayed an overall lower insulin response and lower IL-6 concentrations compared with the LP group (P < 0.05). Furthermore, the groups HP and HPB showed lower hunger sensations compared to the LP group (P < 0.05). Here we show that the abundance of gut Prevotella and Bacteroides at baseline did not stratify metabolic responders and non-responders to barley DF intervention. However, our results indicate the importance of gut microbiota in host metabolic regulation, further suggesting that higher Prevotella/Bacteroides ratio may be favorable. CLINICALTRIALS. NCT02427555.