The Gastrointestinal Tract as a Key Target Organ for the Health-Promoting Effects of Dietary Proanthocyanidins

Abstract

Proanthocyanidins (PACs) are polymers of flavan-3-ols abundant in many vegetable foods and beverages widely consumed in the human diet. There is increasing evidence supporting the beneficial impact of dietary PACs in the prevention and nutritional management of non-communicable chronic diseases. It is considered that PACs with a degree of polymerization >3 remain unabsorbed in the gastrointestinal (GI) tract and accumulate in the colonic lumen. Accordingly, the GI tract may be considered as a key organ for the healthy-promoting effects of dietary PACs. PACs form non-specific complexes with salivary proteins in mouth, originating the sensation of astringency, and with dietary proteins, pancreatic enzymes, and nutrient transporters in the intestinal lumen, decreasing the digestion and absorption of carbohydrates, proteins, and lipids. They also exert antimicrobial activities, interfering with cariogenic or ulcerogenic pathogens in the mouth (Streptococcus mutans) and stomach (Helicobacter pylori), respectively. Through their antioxidant and antiinflammatory properties, PACs decrease inflammatory processes in animal model of gastric and colonic inflammation. Interestingly, they exert prebiotic activities, stimulating the growth of Lactobacillus spp. and Bifidobacterium spp. as well as some butyrate-producing bacteria in the colon. Finally, PACs are also metabolized by the gut microbiota, producing metabolites, mainly aromatic acids and valerolactones, which accumulate in the colon and/or are absorbed into the bloodstream. Accordingly, these compounds could display biological activities on the colonic epithelium or in extra-intestinal tissues and, therefore, contribute to part of the beneficial effects of dietary PACs.

Ethnopharmacology, Chemistry and Biological Properties of Four Malian Medicinal Plants

“…Proanthocyanidins may also be involved in the use of the plant against gastric pains and diarrhea [66]. As for many ethnopharmacologically used plants, clinical data are lacking.…”

Insoluble-Bound Polyphenols Released from Guarana Powder: Inhibition of Alpha-Glucosidase and Proanthocyanidin Profile

“…In the case of proanthocyanidins (condensed tannins), polymeric structures show higher inhibitory activity compared to their monomeric counterparts (e.g., catechin and epicatechin). Due to their presence in the bound form in nature, the potential health effects of IBPPs are mainly related to gut health, with modulation of gut bacteria, protection of the colon mucosa, which may lead to systemic effects [20][21][22].…”

Nutritional and Functional Properties of Extruded Cassava‐Soy Composite with Grape Pomace

“…The inhibitory effects of tannins on α‐amylase is reported to be concentration dependent. Polymers have higher inhibitory activity against α‐amylase than oligomers while reverse is the case for α‐glucosidase . Miao et al in a study on grape pomace extract inhibition of α‐amylase in vitro reported a non‐competitive inhibition of pancreatic α‐amylase by grape pomace extract.…”