Host-microbiota interactions in inflammatory bowel disease

Key studies published in 2019 highlight novel concepts regarding the pathogenesis of inflammatory bowel disease: the emerging role of host-microorganism interactions and the regional microbiota as disease drivers, and the identification of new therapeutic targets. These findings suggest new avenues for research and define important hallmarks for clinical diagnosis and therapy. Key advances Specific microbial pathways control intestinal epithelial cell and barrier function and determine responsiveness to anti-TNF therapy, suggesting that targeting of these pathways is relevant for inflammatory bowel disease (IBD) therapy3; increased , , , Lachnospiraceae, and taxa are related to successful outcome (clinical response or remission) of anti-TNF therapy in Crohn's disease. BifidobacteriumCollinsellaLachnospiraRoseburiaEggerthellaMany defined microbial metabolites are depleted in individuals with IBD versus control individuals, indicating that loss of metabolic diversity occurs with dysbiosis and loss of taxonomic diversity in the IBD microbiome4. The transcription factor c-MAF is a key factor in gut regulatory T cells that maintains host-microorganism homeostasis and prevents gut inflammation5.