Oral microbiome and inflammatory bowel disease: New understanding and call to action.

The oral microbiome is the second largest microbial community in the human body after the gut microbiome. It includes an array of fungi, bacteria, amoebae, flagellates, archaea, and viruses, all of which are potential pathogens. This microbiome can act as a facilitator not only for protection but also for aggravation when dysbiosis occurs. Although conventional thought is this is primarily in terms of oral health issues, such as dental caries and gingival disease. The systemic effects of the oral microbiome however, are relevant to both gastrointestinal (GI) disease and non-GI disease. These systemic risks occur for several reasons, including upregulation of cytokines, adhesion cell-like processes, toll-like receptors, reactive oxidative species or generation of mutation inducing DNA changes. Additionally, there is translocation risk of potential active pathogens or their metabolic byproducts. There is a substantial and growing body of evidence that the oral microbiome influences diseases including Barrett's esophagus, metabolic-associated steatosis liver disease, and GI cancers. Additionally, there is burgeoning evidence of a causal association with systemic inflammatory diseases, including inflammatory bowel disease. This report discusses the most recent evidence of this association and highlights new approaches to potentially enhance our "best practice" strategies for optimal care of patients with inflammatory bowel disease.