Effects of Fat-Soluble Vitamins on Gut Microbiome Composition: A Scoping Review.

As the gut microbiome emerges as a key player in human health, numerous studies have reported its close association with various diseases. Consequently, increasing attention has been given to exploring whether fat-soluble vitamins can modulate gut microbiome composition as a potential strategy to maintain microbial balance. This scoping review aimed to investigate whether interventions with fat-soluble vitamins (vitamins A, D, E, and K) could alter gut microbiome composition and, in turn, improve health outcomes. A total of 17 human studies and 47 animal studies were identified across 4 databases. Most studies reported that fat-soluble vitamins effectively altered gut microbiome composition; however, evidence linking these changes to consistent improvements in health outcomes remains limited. Overall, this review maps the potential link between vitamin-driven microbiome modulation and health benefits, while highlighting current research gaps to guide future investigations.