Normally in health, the commensal gut microbiota lives in a perfectly symbiotic relationship with the host. Initial bacterial colonization occurs through the maternal vaginal/fecal flora and oral feeding. When this symbiotic relationship is lost due to several factors, the condition is known as “dysbiosis.” Dysbiosis is associated with the pathogenesis of intestinal disorders, such as inflammatory bowel disease, irritable bowel syndrome (IBS), and coeliac disease, but recent studies have shown that it has also been implicated in extraintestinal disorders, such as allergy, asthma, cardiovascular disease, obesity, autoimmune diseases, inflammatory diseases, and some mental disorders and cancers. The proposed mechanism for the development of such disorders is disruption of the pivotal mutual relationship between the gut microbiome, the metabolic products produced by them, and the host immune response. In this review article, we would like to highlight the role of gut microbiota in the development of extraintestinal diseases.
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