The Gut-Brain Connection: The Association Between Gut Microbiota Composition and the Pathogenesis of Multiple Sclerosis Among Adults

Abstract

Background: Multiple Sclerosis (MS) is a chronic autoimmune disease of the central nervous system characterized by demyelination and axonal damage. It is estimated that approximately 2.5 million people in the world are living with the disease. Despite a great deal of research, little is known on the cause of MS. The human gut contains trillions of bacteria and has been shown to play a major role in health and disease. Thus, the role of the gut microbiota has emerged as an area of interest in the pathogenesis of MS.

Objective: The aim is to review the literature to assess whether or not there is an association between gut microbiota composition and the pathogenesis of MS among adults aged 18 years or older.

Method: A structured literature review was conducted by searching PubMed and Scopus databases. Keywords searched were: “Multiple Sclerosis”, “gut bacteria”, “gut microbiome”, “gut microbiota” and “dysbiosis”. Studies included were limited to those available in English language, published in the past 10 years, and to those including participants aged 18 years or older.

Results: After assessment of the relevance and eligibility of the articles retrieved, a total of 6 studies were selected. Selected studies were case-control design and they mostly found that the gut microbiota composition of MS cases had significant differences in comparison to controls.

Conclusion: The findings suggest that there may be an association between altered gut microbiota composition and the pathogenesis of MS. However, because the studies were limited to small sizes and were subject to confounding effects, it is not possible to definitively conclude an association between the two. Further studies are required and should be larger-scale and longitudinal, as well as focus on implementing methods to adjust for potential confounders such as diet, genes, age, sex, ethnicity, etc.