What does irritable bowel syndrome share with non-alcoholic fatty liver disease?

Abstract

Non-alcoholic fatty liver disease (NAFLD) and irritable bowel syndrome (IBS) are two very common diseases in the general population. To date, there are no studies that highlight a direct link between NAFLD and IBS, but some recent reports have found an interesting correlation between obesity and IBS. A systematic PubMed database search was conducted highlighting that common mechanisms are involved in many of the local and systemic manifestations of NAFLD, leading to an increased cardiovascular risk, and IBS, leading to microbial dysbiosis, impaired intestinal barrier and altered intestinal motility. It is not known when considering local and systemic inflammation/immune system activation, which one has greater importance in NAFLD and IBS pathogenesis. Also, the nervous system is implicated. In fact, inflammation participates in the development of mood disorders, such as anxiety and depression, characteristics of obesity and consequently of NAFLD and, on the other hand, in intestinal hypersensitivity and dysmotility.

Keywords: Non-alcoholic fatty liver disease; Irritable bowel syndrome; Low grade chronic inflammation; Cytokines

Core tip: The link between non-alcoholic fatty liver disease (NAFLD) and irritable bowel syndrome (IBS) should be carefully evaluated in future research, representing an intriguing field of investigation. A better understanding of the role of systemic inflammation and activation of the immune system may be necessary to clarify obscure points of NAFLD and IBS pathogenesis, and therefore it can be helpful in the development of new therapies.