Bioactive Collagen Peptides in Veterinary and Biomedical Science—Part II: The Gut–Collagen Peptide Axis, Bile Acid Signaling, and Translational Therapeutic Applications

Abstract

Simple Summary Collagen supplements are usually thought of as joint or skin remedies, but the small collagen fragments released during digestion reach far more of the body than the joints alone. This review, the second of two parts, follows these fragments from the gut outward. In the intestine they help seal the gut lining, shift the balance of gut bacteria, and alter bile, the digestive fluid made by the liver. Through these routes they can influence appetite, blood sugar, fat tissue, the liver, and even the brain. We sort the evidence carefully, separating proven clinical results from promising early findings. The firmest veterinary evidence supports collagen fragments for joint disease in dogs and horses, and dietary taurine—a different nutrient that also works through bile—for a reversible form of heart-muscle disease in certain dog breeds. Newer laboratory work points to effects on fat-burning, memory, and blood clotting, but these still need confirmation in animals before any clinical claim. The practical message is that diet shapes a shared gut–bile signalling system, and that collagen and taurine act on it as separate dietary inputs, with real relevance for companion animals, horses, and livestock.