Since my diagnosis of celiac disease I’ve been interested in all aspects of the science about gluten, the trigger for bowel damage and other problems in those of us with this disease.
Web searches are often a clue to the popularity of different approaches. The top hit on Google for “gluten, microbiome” was by Dr. David Perlmutter, author of Grain Brain, whose work I have discussed in earlier blogs. Dr. Perlmutter discusses early gluten exposure and increased type 1 diabetes and mouse studies showing microbiome changes with development of diabetes associated with gluten exposure. He emphasizes the importance of the microbiome for a well functioning immune system and health.
What does a review of the scientific literature show?
1- Change to a gluten free diet produces a modest change to the microbiome which mainly is a decrease in “healthy” bacteria and an increase in “unhealthy” bacteria. One investigator hypothesized that this might be due to less dietary fiber since gluten containing grains are a major healthy fiber source for many.
2. Change to a whole food plant based diet produces a radical change in the microbiome with the opposite effect to a gluten free diet.
3. There is large variation in the microbiome between different populations and even in the same individual from week to week. Some is probably genetic but other variation is due to diet, exercise, sleep and other lifestyle factors.
4. A recent extensive review noted “there is misconceived perception that this diet (gluten free) is healthier.” The reviewer goes on to say that gluten containing foods provide many other important nutrients.
5. A cardiologist whose website is “glutenfreecardiologist” offers a reasonable approach: try a gluten free diet for a few weeks; if you feel better continue, but be sure to get lots of fiber and other nutrients from other sources (limit meat, dairy, sweets in favor of other whole grains, legumes and plant food.)