Probiotics for mitigating diarrhea in yak calves: Mechanisms, efficacy, and future perspectives

Yak calves are a vital economic asset within high-altitude pastoral ecosystems; however, diarrhea continues to pose a significant threat to their health and growth, leading to substantial financial losses. In recent years, probiotics derived from plateau environments have attracted growing interest as sustainable alternatives to conventional antibiotic therapies. These beneficial microorganisms act through multiple mechanisms, including restoration of gut microbiota equilibrium, enhancement of intestinal barrier integrity, modulation of immune responses, and suppression of pathogenic colonization. This review systematically consolidates current evidence on the efficacy of probiotics in both preventing and treating diarrhea in yak calves and critically evaluates the underlying biological mechanisms. Additionally, we address challenges associated with product viability, formulation design, and host-specific applicability, while proposing future research directions to refine these interventions and facilitate their integration into practical veterinary use. By providing a comprehensive theoretical foundation and actionable insights, this review seeks to advance the development of effective probiotics strategies that enhance yak calf health and productivity within sustainable livestock operations.