Interactions between Salivary Proteins and Dietary Polyphenols: Potential Consequences on Gastrointestinal Digestive Events

Abstract

The present review documents the current knowledge and hypotheses on how polyphenols−saliva interactions may modulate the bioaccessibility or bioavailability of nutrients and highlights research prospects in the field. After an updated description of the different classes of dietary polyphenols and their modifications by food processing or digestion, an overview of interactions between salivary proteins and polyphenols (with an emphasis on tannins) is provided. In vitro studies show that the solubility of salivary protein−tannin complexes in gastric conditions depends on the degree of tannin polymerization, while complexes are partly solubilized by bile salts. Salivary proteins−polyphenols interactions may affect digestive processes. For example, polyphenols can bind to and inhibit salivary amylase, with downstream consequences on starch digestion. Some salivary proteins (PRPs) prevent tannin-induced reduced protein digestibility, probably through binding tannins before they interact with digestive proteases. Salivary proteins may also act as scavenger molecules to limit the intestinal uptake of tannins.

Grape Polyphenols in the Treatment of Human Skeletal Muscle Damage Due to Inflammation and Oxidative Stress during Obesity and Aging: Early Outcomes and Promises

“…Molecules such as tannins can form a complex and precipitate with the tannin-binding salivary proteins (TBSPs). These complexes remain stable during the transit in the stomach, while they are solubilized in the intestine in presence of bile salts [ 177 ]. Lipophilic polyphenols such as resveratrol, curcumin, and quercetin are poorly bioavailable because of their lack of solubility, thus limiting their antioxidant action in the body.…”

Interactions between Salivary Proteins and Apple Polyphenols and the Fate of Complexes during Gastric Digestion

“…3 Depending on their concentration and chemical structure, some polyphenols referred to as tannins may also exhibit some antinutritional properties, for example, by binding to and inhibiting digestive enzymes. 4 In any case, the effects of polyphenols depend first on whether they are available in free form in the lumen of the digestive system; thus, the complexation of polyphenols with other molecules, typically polysaccharides or proteins, may interfere with their potential intestinal absorption or their putative local antioxidant action. The binding of tannins by proteins may act as a protective mechanism against their deleterious effects on digestion.…”

Reduction of phenolics in faba bean meal using recombinantly produced and purified Bacillus ligniniphilus catechol 2,3-dioxygenase

“…are intrinsic to pulses, and in the context of animal nutrition, are considered anti-nutritional factors (ANFs) based on observed negative effects on digestion and the bioavailability of nutrients (Kardum and Glibetic 2018 ; Kumar et al 2021 ). These effects are due to phenolics forming complexes with storage proteins, interfering with peptide bond proteolysis, and serving as direct inhibitors of digestive enzymes, together decreasing protein and carbohydrate availability (Morzel et al 2022 ; Punia et al 2021 ). Chelation of metal ions by poly-phenolics has also been shown to reduce absorption and decrease uptake of vitamins and minerals (Singh 2017 ).…”