HIGH FIBER MEDITERRANEAN DIET PROMOTES HEALTHY GUT BACTERIA & BETTER HEART HEALTH

Numerous studies have found the Mediterranean diet and other plant-rich dietary patterns are beneficial to heart health.  The Mediterranean diet is plentiful in fruits, vegetables, legumes, nuts and whole grains; moderately high in olive oil and fish; and low in red meat, sweets, and dairy products.  An interesting recent study reveals one way that Mediterranean-style diet is beneficial is that it boosts gut bacteria production of short-chain fatty acids (SCFA’s).  These are the preferred fuel of our intestinal cells and higher levels have been found to decrease systemic inflammation and improve immune function.  SCFA’s are associated with better cardiovascular and metabolic health, lower rates of insulin resistance and diabetes, decreases in the risk for autoimmune diseases, and decreases in the risk of colon cancer.

The study of 153 adults tracked dietary intake and levels of gut bacteria and their metabolites in stool and urine.  Researchers found a clear pattern of higher SCFA levels in those who consumed more fiber-rich foods, especially those consuming plenty of beans. Participants whose diet most closely resembled the Mediterranean diet, whether vegan, vegetarian, or omnivore, had the highest levels of SCFA production.  Interestingly, vegan diets were the diet that most frequently resembled the Mediterranean diet.   

The study also showed that vegans or vegetarians had the lowest levels of a gut bacterial metabolite called trimethylamine oxide (TMAO).  Eggs, beef, pork and fish are the primary sources of carnitine and choline--compounds that are converted by gut microbes into trimethylamine, which is then processed by the liver and released into the circulation as TMAO.  TMAO levels appear to increase heart disease risk.  Among non-vegetarians, people who adhered to the Mediterranean diet also had relatively low TMAO levels.  

What to do:  Eat more fiber rich foods.  Fruits, vegetables, whole grains, nuts, and beans are all fantastic sources of dietary fiber.  Typically, our first consideration when planning a meal is the protein option (usually fish, chicken, or meat).  Instead, try meal planning by first considering the vegetable component.  Aim to make half your plate vegetables.  Also, beans and nuts are easily added to a variety of dishes, so mix things up a bit and add them in your favorite dishes to give your fiber intake a healthy boost.

Sources:

Filippis F, Pellegrini N, Vannini L, et al.  High-level adherence to a Mediterranean diet beneficially impacts the gut microbiota and associated metabolome. Gut.  2015, published online ahead of print September 28, 2015. DOI: 10.1136/gutjnl-2015-309957

Den Besten G, Van Eunen K, Groen AK, et al.  The role of short-chain fatty acids in the interplay between diet, gut microbiota, and host energy metabolism.  Journal of Lipid Research. 2013;54(9):2325-2340. DOI:10.1194/jlr.R036012.

Adapted from articles available at:

http://www.sciencedaily.com/releases/2015/09/150929070122.ht

http://consumer.healthday.com/vitamins-and-nutrition-information-27/dietary-fiber-health-news-308/high-fiber-foods-gut-release-batch-1955-703617.html