Indication: Prebiotic potential
Source: Am J Clin Nutr, January 2011;93(1):62-72.
Research: Researchers assessed the prebiotic potential of cocoa flavanols in a randomized, double-blind, crossover, controlled intervention study. Participants included 22 healthy human volunteers who were randomly assigned to either a high-cocoa flavanol (HCF) group (494 mg cocoa flavanols/day) or a low-cocoa flavanol (LCF) group (23 mg cocoa flavanols/day) for 4 weeks. This was followed by a 4-week washout period before volunteers crossed to the alternant arm. Fecal samples were recovered before and after each intervention, and bacterial numbers were measured by fluorescence in situ hybridization.
Results: Compared with the consumption of the LCF drink, the daily consumption of the HCF drink for 4 weeks significantly increased the bifidobacterial and lactobacilli populations but significantly decreased clostridia counts. These microbial changes were paralleled by significant reductions in plasma triacylglycerol and C-reactive protein concentrations. Furthermore, changes in C-reactive protein concentrations were linked to changes in lactobacilli counts. These in vivo changes were closely paralleled by cocoa flavanol-induced bacterial changes in mixed-batch culture experiments. According to researchers, this study shows that consumption of cocoa flavanols can significantly affect the growth of select gut microflora in humans, which suggests the potential prebiotic benefits associated with the dietary inclusion of flavanol-rich foods.