Yogurt as a modulator of gut and beyond gut: Mechanisms, health effects, and clinical translation.

Yogurt, a fermented dairy food, has been increasingly recognized for its potential to modulate gut microbiota and promote host health. Accumulating evidence suggests that yogurt consumption influences gut microbial composition, diversity, and functional activity. In this narrative review, we synthesized the findings on yogurt-related effects on the gut microbiota, intestinal barrier, microbial metabolites, immune responses, and selected extra-intestinal outcomes. We distinguished traditional yogurt, probiotic yogurt, synbiotic yogurt, fortified yogurt, and non-dairy or regional yogurt-like fermented products, and then organized proposed mechanisms into a hierarchical framework that separated direct yogurt-derived inputs, including starter cultures, added probiotic strains, fermentation-derived compounds, and dairy matrix components, from resident microbiota-mediated secondary metabolites and host downstream responses. Importantly, limitations and controversies, such as variability in yogurt formulations, strain-specific effects, and inter-individual responses, were critically evaluated. Finally, we highlighted future research directions that emphasize standardized study designs, defined endpoints, long-term randomized controlled trials, and integrative multi-omics approaches to support the development of personalized dietary strategies. Together, this review provides a structured framework for understanding the complex interactions between yogurt, gut microbiota, and host physiology, while outlining key steps needed to translate evidence into actionable nutritional recommendations.