Current understanding of starch-polyphenol complexes and their potential <i>in vivo</i> metabolism, impact on gut microbiota and treating diabetes

Starch-polyphenol complex is defined as a new type of resistant starch, while its in vivo metabolism, impact on gut microbiota, and possible application in treating diabetes are less clear. This review aimed to summarize recent findings on the diverse structures of polyphenols and their interaction patterns with starch, in vitro and in vivo metabolisms of these complexes, synergistic interactions between these complexes and gut microbiota, and practical applications of these complexes in alleviating type 2 diabetes. Both inclusion and non-inclusion complexes can be developed between starch and polyphenols, depending on the differences in structures and processing methods. The formation of complexes may enhance bioavailability of polyphenols in vivo, stimulate growth of beneficial gut bacteria from Bifidobacterium, Lactobacillus and Prevotella phylum, and contribute to the alleviation of diabetes, while the underneath mechanisms remain to be further explored. These insights highlight the potentials of applying starch-polyphenol complexes as prebiotics to improve human health.