Orally Available Collagen Tripeptide: Enzymatic Stability, Intestinal Permeability, and Absorption of Gly-Pro-Hyp and Pro-Hyp

Collagen-derived small peptides, such as Gly-Pro-Hyp (GPH) and Pro-Hyp (PH), play a role in various physiological functions. Although collagen degrades in the gastrointestinal tract randomly and easily, it is not readily cleaved into bioactive peptides. To increase the bioavailability of bioactive peptides, a collagen tripeptide (CTP) was prepared from fish scales by the digestion method using collagenase from nonpathogenic Bacillus bacteria. It was demonstrated that Hyp-containing peptides GPH and PH were better absorbed and reached higher plasma levels after the oral administration of CTPs in rats compared to high molecular weight collagen peptide (H-CP). GPH and PH were stable in gastrointetiiial:fluid and rat plasma for 2 h, and GPH was able to be transported across the intestinal cell monolayer. These results suggest that :the ingestion of CTP is an efficient method for taking bioactive peptides orally due to the enzymatic stability and intestinal permeability of GPH and PH.