May 22, 2017
421 Fiber and Auto-Immune Disease [22 May 2017]
We’ve always known that dietary fiber is important for regular bowel movements. In a few previous articles [#140 November 2011 and #276 July 2014] I wrote about the benefits of soluble and insoluble fiber to balance blood sugar and maintain a healthy weight. Now scientists have discovered a link between dietary fiber, our immune system, and auto-immune diseases. How does that work?
Rhonda Patrick, in December 2015, interviewed Drs. Justin & Erica Sonnenburg who run a lab at Stanford University looking at “the profound impact gut bacteria has on our entire body” (Justin). They found that dietary fiber is essential for a healthy microbiome, described as “an incredibly complex and dynamic ecosystem of microbes” (Erica). In this 40 minute interview (which I encourage you to watch for yourself) Drs. Sonnenburg describe the connections between gut bacteria and our body's immune system.
The average American eats 10-15 grams of fiber daily, short of the government recommended 30-35g, and far short of the 100-150g consumed by traditional hunter-gatherer populations (who have a much greater diversity in their gut microbiomes and a significantly lower incidence of auto-immune disease).
The microbes in the colon rely on complex carbohydrates (fiber) for food, metabolizing it into short chain fatty acids (SCFAs) and other beneficial compounds. These SCFAs then feed the epithelial cells of the colon wall. SCFAs also increase the T regulatory cells which have an anti-inflammatory effect, calming the immune system. When fiber is lacking, the microbes attack the mucus lining of the colon and in turn are attacked by the immune cells in the intestinal wall, creating an inflammatory effect. Without adequate T regulatory cells, this can lead to auto-immune conditions like allergies, inflammatory bowel disease, rheumatoid arthritis and MS.
Many of these auto-immune diseases have previously been linked to gut microbiome disruptions – this provides a likely explanation. Taking this further, heart disease, metabolic disorders, some cancers, and even aging are all increased by inflammation so could also be reduced with a healthy gut microbiome.
So how to improve our gut microbiome? Feed them a variety of complex carbs from fruit, vegetables, whole grains, and legumes. The more types of fiber, the more diverse the bacterial populations they will support; fiber supplements often have only one or two sources. Use probiotic supplements and foods (like yogurt, sauerkraut and fermented vegetables) to help repopulate the gut following a round of antibiotics or whenever you suspect it needs a boost.
For more information on this topic, see the Sonnenburgs' book The Good Gut - Taking Control of Your Weight, Your Mood and Your Long-term Health or visit their Facebook page.
For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.