Figure 1. Carbohydrate composition of the whole grains used in the study and trial design. Twenty-eight subjects participated in a randomized 17-week crossover study that investigated the impact of brown rice (BR), whole-grain barley (WGB) and a combination of the two on gut microbiota composition and metabolic and immunological markers. Stool samples and blood samples (indicated by red arrows) were collected during the baseline and at the end of each treatment period.