Food‐derived peptides and intestinal functions

Abstract

Many researchers have reported that food proteins and their peptides expressed a variety of functions in the body, including a reduction of blood pressure, modulation of immune cell functions, and regulation of nerve functions. However, food-derived proteins and peptides also play important roles in the intestinal tract before being absorbed. For example, some of the proteins and peptides can regulate the activity of digestive enzymes in the intestinal tract, thereby modulating the nutrient absorption in the intestines. These proteins and peptides have been used for functional foods with blood glucose- and blood cholesterol-lowering effects. Enhancement of the intestinal calcium absorption by casein-derived peptides is another example, such peptides being used as functional food ingredients. We have recently observed that certain milk peptides might stimulate the calcium transporter in intestinal epithelial cells. Carnosine, a dipeptide contained in skeletal muscles, was observed to suppress the secretion of inflammatory cytokines by intestinal epithelial cells that had been exposed to oxidative stress. Understanding the behavior of dietary proteins and peptides in the intestines is important for designing functional foods with physiological functions.

Sequential release of milk protein–derived bioactive peptides in the jejunum in healthy humans

“…This protein material is hydrolyzed by luminal gastric and pancreatic enzymes and epithelial brush border membrane peptidases into a complex mixture of oligopeptides, dipeptides, tripeptides, and free amino acids that transit and are progressively absorbed along the small intestine. Different studies have suggested that bioactive peptides released from dietary protein during digestion could exert metabolic and physiologic actions by acting on specific targets at the digestive level or after absorption (2)(3)(4)(5), and some studies have particularly identified potential bioactive peptides in the sequence of milk proteins (6).…”

“…Accordingly, this study aimed to characterize digestion products and, particularly, peptides released in the jejunum after ingestion of either milk casein or whey proteins (WPs) 5 in healthy human subjects. We used a gastrointestinal tube technique to collect effluents as well as mass spectrometry (MS) to extensively identify and quantify milk protein-derived peptides.…”

Whey Proteins as Source of Bioactive Peptides Against Hypertension

“…Tests encompassing hypertensive animals and human clinical trials have shown that certain sequences can lower blood pressure; however, it is difficult to establish a direct link between the ability to inhibit ACE in vitro and the actual antihypertensive activity in vivo. Knowledge of the mechanism of action of such bioactive peptides is obviously crucial before manufacture of functional foods with physiological properties is in order [268].…”

New insights into the immunological effects of food bioactive peptides in animal models of intestinal inflammation

“…In addition, a group of peptides can also act as biocarriers for Ca and other minerals, increasing their bioavailability (8,9) . The activities of milk peptides and products containing them have been recently reviewed elsewhere (1,2) .…”