Plant Polyphenols as Inhibitors of Hydrolases are Regulators of Digestion

<b><i>Background:</i></b> There are numerous reports on the use of polyphenol-containing foods and various medicinal plant preparations for the prophylaxis and therapy of metabolic diseases, such as metabolic syndrome and diabetes mellitus, respectively. One unifying aspect to the effect of these natural compounds is their ability to inhibit digestive enzymes, which is the focus of this review. <b><i>Summary:</i></b> Polyphenols inhibit nonspecifically hydrolytic enzymes included in the digestion process, e.g., amylases, proteases, lipases. By that, the digestion process is protracted with different consequences as result of the incomplete absorption of monosaccharides, fatty acids, and amino acids as well as for the enhanced availability of substrates for the microbiome in ileum and colon. The resulting postprandial blood concentration of monosaccharides, fatty, and amino acids is lowered and by that different metabolic pathways proceed more slowly. As another positive result, polyphenols can also modulate the intestinal microbiome and thus mediate additional beneficial health effects. <b><i>Key Messages:</i></b> Many medicinal plants possess a broad spectrum of different polyphenols, thereby mediating the nonspecific inhibition of all hydrolytic enzyme activities in the gastrointestinal digestive process. As a consequence of the slowing down of digestive processes, risk factors for the development of metabolic disorders are reduced and the health of the patients with metabolic syndrome improves.