Managing Gut Dysbiosis: Clinical Evidence and Perspectives on Saccharomyces boulardii CNCM I-745 for Diarrhoeal Conditions in Adults and Children

The human gut microbiota plays a key role in health and disease across the lifespan and is shaped by complex intrinsic and extrinsic factors. Dysbiosis is increasingly recognized as a contributor to a wide range of clinical conditions, with diarrhoea—particularly antibiotic-associated diarrhoea—representing an early clinical marker of microbiota disruption. This narrative review summarizes current evidence on the probiotic yeast Saccharomyces boulardii CNCM I-745 and its clinical applications in both paediatric and adult populations. Available clinical data support its safety and efficacy in the prevention and management of gastrointestinal disorders, particularly diarrhoeal conditions, and suggest a potential role in promoting microbiota resilience. Key mechanisms of action, safety considerations, and findings from randomized controlled trials and meta-analyses are discussed. However, current data remains limited by heterogeneity among studies and a lack of long-term, mechanistic data, highlighting the need for further well-designed studies to clarify its role across different clinical settings.