Th17 immune response in inflammatory bowel disease: Future roles and opportunities for lactic acid bacteria and bioactive compounds released in fermented milk

Background: Evidence have shown that Th1-and Th17-related cytokines are often elevated in inflammatory bowel diseases (IBD). Hence, targeting Th17 cells or their effector cytokines represents an attractive alternative for treatment IBD. In this context, recent evidence have indicated that fermented dairy products, with specific lactic acid bacteria, selectively targeting the Th17 lineage, suggesting their effectiveness in preventing and treating IBD. Scope and approach: This review aims to present an overview of the available information on the role of Th17 in inflammatory bowel diseases, and on the potential of fermented milk in the prevention and management of IBD, by modulating this response. Key findings and conclusions: Recent evidence has shown that fermented milks may contain specific bacteria and/ or bioactive compounds (e.g., peptides, exopolysaccharide, free amino acids, organic acid and vitamins) released during fermentation, capable to downregulate the production of pro-inflammatory cytokines related to Th17 cells, including IL-17, IL-10, IFN, IL-6, IL-23, and TGF-beta, by modulating TLR signaling and differentiation of native Th cells into Th1, Th2 or Th17 effector cells. Hence, such fermented milks represent a promising alternative for the treatment of IBD. However, further studies are required to elucidate the molecular mechanisms of bacteria and bioactive components responsible of such anti-inflammatory effects.