Resistant starch utilization by Bifidobacterium , the beneficial human gut bacteria.

Resistant starch (RS) reaches the large intestine largely intact, where it is fermented by the gut microbiota, resulting in the production of short-chain fatty acids (SCFAs) that have beneficial effects on the human body. Bifidobacteria are a major species widely used in the probiotic field, and are increased in the gut by RS, indicating their importance in RS metabolism in the intestine. Bifidobacteria have a genetic advantage in starch metabolism as they possess a significant number of starch-degrading enzymes and extraordinary three RS-degrading enzymes, allowing them to utilize RS. However, to date, only three species of RS-degrading bifidobacteria have been reported as single isolates B. adolescentis, B. choerinum , and B. pseudolongum . In this review, we describe recent studies on RS utilization by Bifidobacterium , based on their biochemical characteristics and genetic findings. This review provides a crucial understanding of how bifidobacteria survive in specific niches with abundant RS such as the human gut.