Fructooligosaccharides and immune health: immunomodulatory effects via gut microbiota and direct molecular mechanisms

Fructooligosaccharides, a prebiotic oligosaccharide, are gaining attention for their beneficial effects on immune health. These benefits are often linked to their ability to promote the growth of beneficial gut bacteria, which produce metabolites such as short-chain fatty acids with immunomodulatory properties. In addition, FOS may have direct immunomodulatory roles by interacting with carbohydrate-binding receptors on epithelial and immune cells, including monocytes, macrophages and dendritic cells. These interactions can initiate distinct downstream responses, such as suppressing pro-inflammatory cytokine production,and inducing immune tolerance. In this review, we will discuss recent findings on the mechanisms of immune modulation following FOS supplementation and their potential applications in various disease settings. Additionally, we aim to present current evidence supporting the direct immunomodulatory effects of FOS on immune and epithelial cells. Finally, we will identify existing knowledge gaps and propose future research directions to advance our understanding of FOS in immune health.