Nexus of Whey Proteins, Gut Dysbiosis, and Colonic Health

The gut microbiota is essential for colonic health, and its imbalance (dysbiosis) is linked to conditions like inflammatory bowel disease and metabolic disorders. Whey proteins (WPs), including β-lactoglobulin, α-lactalbumin, glycomacropeptide, and lactoferrin, possess antimicrobial, immunomodulatory, and prebiotic-like properties that may help restore microbial balance. Beyond modulating the microbiome, WPs play a significant role in reinforcing intestinal barrier integrity and regulating host metabolism. This review summarizes evidence from in vitro, in vivo, and clinical studies showing WPs can enhance beneficial bacteria (e.g., <i>Bifidobacterium</i>, <i>Lactobacillus</i>) while suppressing harmful ones. Furthermore, WP supplementation has been shown to alleviate dysbiosis-related conditions such as colitis, obesity, and allergies by improving microbial diversity, enhancing short-chain fatty acid production, strengthening the mucosal barrier, and modulating immune responses. However, the effects vary depending on WP composition, processing, and individual microbiota. Despite encouraging results, knowledge gaps remain regarding optimal dosing and long-term impacts. Overall, WPs show promise as functional food components and potential therapeutic agents for promoting colonic health, metabolic homeostasis, and gut barrier function, but more research is needed to refine their clinical application.