A review of research studies and clinical cases in Japan suggests role of gut environment in development of multiple sclerosis

Key Points

• Gut environment can influence central nervous system.
• Western-style dietary habits are potentially risk factor for MS development.
• Changes in gut microbiome possibly affect development and severity of MS disease.

Summary

Gut is the largest immune organ with vast number and variety of immune cells residing in it. It is thought that gut-residing immune cells move to central nervous system (brain and spinal cord) and can affect neurological conditions like multiple sclerosis (MS). In a recent review published in the journal “Neurochemistry International” (published May 2019, https://pubmed.ncbi.nlm.nih.gov/31152766/, authors took into consideration various type of studies including epidemiological, clinical cases and microbiome studies and pointed out the role of environmental factors especially dietary changes in development of MS.

Epidemiological studies show high prevalence of MS in North America, Europe and Australia but low prevalence in Asia, South America and Africa. Immigration studies suggest that place of residence during young age and age of immigration affects the future risk of developing MS which indicates role of environmental factors. Number of MS cases in Western countries are increasing. Interestingly, Japan has seen almost 20-fold increase in MS cases between 1980 and 2014. Such dramatic increase cannot be explained by genetic changes and raises the question about effects of environmental factors in development of MS.

One of the authors observed Japanese cases where individuals developed MS during their stay (more than one year) in North America or Europe. Additionally, many patients reported irregular eating habits and constipation at time of onset of disease. Some patients experienced control in disease activity by changing diet from Western type to traditional Japanese. Along with MS, Japan has seen increase in inflammatory bowel disease with high fat diet being the risk factor. Based on above findings authors hypothesized that change in diet at population level has made people in Japan more susceptible to diseases like MS and inflammatory bowel disease.

Other evidence supporting role of gut-environment comes from microbiome studies. Microbiome is bacteria living in our gut, and studies show that microbiome in MS patients are different from healthy individuals. When microbiome from MS patient is introduced in mice model of the disease, mice develops more severe disease symptoms compared to when microbiome of healthy individuals is introduced.

Thus our suggestion is to eat a more diverse diet with a goal of 200 different plant species which may shift your microbiome to a healthier mix of microbes. Pick up a handout for the diet that we have used in our clinics and clinical trials at https://terrywahls.com/diet/ .