Protein conjugates and probiotic interactions of dairy products for innovative and future functional foods

This review critically assesses the strategies and mechanisms underlying interactions between protein conjugates and probiotics in dairy foods, aiming to detail how these conjugates stabilize probiotics, facilitate gut colonization, and stimulate immunomodulation. Protein–based carriers and complexes play key roles in improving probiotic protection, adhesion, and metabolic activity. Notable strategies include developing milk proteins (e.g., casein and whey proteins), plant–derived protein conjugates, and advanced encapsulation techniques for polysaccharide– protein complexes. The protein shell in conjugates protects probiotics from harsh conditions, enables targeted intestinal release, enhances mucosal adhesion, and contributes to enhanced antioxidant and anti–inflammatory effects. Such strategies also can improve probiotic survival and colonization and reduce inflammation (with increased IL–10 and decreased tumor necrosis factor–alpha), enhance mucus secretion (with a rise in mucin 2 [MUC2]), and elevate beneficial gut microbes. Advancements in probiotic research have enabled more precise and targeted applications using protein conjugates and encapsulation systems. These approaches form part of integrative nutrition strategies that deliver precision, protection, and personalization in the design of functional foods, contributing to food nutrition improvement. Moreover, protein conjugates are increasingly recognized as active modulators of probiotic function and immune signaling, rather than passive carriers, thereby offering new avenues for food production.