Metabolome and inflammasome in inflammatory bowel disease

Inflammatory bowel disease (IBD) encompasses several chronic inflammatory disorders leading to the damage of the gastrointestinal tract. The 2 principal forms of these disorders are ulcerative colitis (UC) and Crohn's disease (CD). Bacteria are involved in the etiology of IBD. Many microorganisms have been put forward as causative factors in IBD, but the primary etiologic agents are still not known. The underlying genetic, environmental, and lifestyle issues can affect the individual's predisposition to these diseases. Immune factors identified in IBD are: dysregulation of the innate and adaptive immune system directed against luminal bacteria or their products found in the intestinal lumen and inappropriate immune responses to organisms in the intestine that normally do not elicit a response, possibly because of intrinsic alterations in mucosal barrier function. However, recent advances in basic science research revealed new insights into the role of specific immune cells and their mediators in intestinal inflammation. The inflammatory mediators known as "inflammasome" are a consequence of the metabolic products (metabolom) of cells and commensal or pathogenic bacteria. Elucidation of inflammasome and metabolom has led to the development of biomarkers specific for each disease that are involved into management strategies targeted at altering specific pathogenic mechanisms that have the potential to modify or change the natural course of these disease entities. The review discusses the potential role of biomarkers in monitoring the inflammasome and therefore the severity of intestinal damage. The microbial ecosystem in the human gut in different microhabitats and metabolic niches contribute to the bowel metabolome.In addition, this review will focus on our expanding understanding of microbial factors associated with both the initiation and maintenance of IBD. New insights acquired from murine genetic models of inflammatory bowel disease will also be discussed.