Ask The GI

Is A Plant-Based Diet Good For My Gut Health?

Google+ Pinterest LinkedIn Tumblr

Is a plant-based diet good for my gut health? The resounding answer is YES! Multiple studies have shown that diet is a driving force in shaping our individual gut microbiota. The food that you choose to eat will leave an imprint on your gut microbial makeup in less than 24 hours. And when we compare what happens on the most basic level between a plant-based diet and an animal-product diet we observe radical differences. 

Notably, that less than five days on an animal-based diet results in:

  • Increased growth of inflammatory bacteria – Alistipes, Bilophila, and Bacteroides – and decreased growth of anti-inflammatory bacteria – Roseburia, Eubacterium rectale, and Ruminococcus bromii.
  • Dramatic increases in Bilophila wadsworthia, a bacteria strongly associated with the development of inflammatory bowel disease like Crohn’s and ulcerative colitis.
  • Significantly lower levels of short chain fatty acids like butyrate and acetate.
  • Increased antibiotic resistance in the gut.
  • Production of more secondary bile salts, which are known to cause colon and liver cancer.

None of the changes that occur with the animal-based diet are good for gut health. If anything, they suggest that a meat-heavy diet predisposes us to dysbiosis, which some refer to as “leaky gut.” 

How do we prevent dysbiosis? The answer also lies in the study above – short chain fatty acids, or SCFAs. SCFAs like butyrate, acetate and propionate have healing effects throughout our body. They strengthen the good gut microbes, and weaken the inflammatory bad ones. They also close the holes in our colon that some call “leaky gut”, optimize our immune system, lower cholesterol, regulate blood sugar, protect us from killers like heart disease, stroke and cancer, and even cross the blood brain barrier to improve brain function.

We want all those benefits, so where do we get them? There’s only one way – prebiotic fiber. And there’s only one place you can get fiber from. Plants! Yes, plants have cornered the market on fiber and SCFAs. There are some out there who may claim that you can find butyrate, one of the SCFAs, in high fat dairy (like butter) or in a supplement. Just to set the record straight, ingested butyrate is not the same as butyrate produced by our microbes. When you eat your butyrate, it’s absorbed almost immediately in the small intestine without ever reaching the large intestine where we need it. This is why all of the studies I’m referencing about the benefits of SCFAs come from the consumption of fiber, and there is no evidence that butter or a supplement is able to adequately recreate these benefits.

But let’s take a step back for a moment here… I’ve just told you that SCFAs that come from dietary fiber strengthen the healthy anti-inflammatory microbes, suppress the unhealthy inflammatory microbes, reverse leaky gut and have healing effects through the body. 

No question, fiber is our most essential nutrient for gut health. But beyond fiber, we also know that every single fruit, vegetable, whole grain, seed, nut and legume has a unique mix of vitamins, minerals and phytochemicals, which are healing chemicals that you find exclusively in plants. And if you’re looking for that last piece of evidence, a groundbreaking study involving more than 11,000 human participants around the world revealed that the single greatest predictor of a healthy gut microbiome was the diversity of plants in the diet.

The benefit of plant fiber for a healthy gut is more than theory – it’s biology. This is deeply ingrained through three million years of microbial and human co-evolution. We need our microbes, they need us. When we feed them fiber, they feed us with short chain fatty acids. It’s an essential and mutually beneficial relationship.

In my book, Fiber Fueled, we take a deep dive into the gut microbiome, showing how our 21st century lifestyle has left us overfed, undernourished, and hyper-medicated. The full healing effects of fiber and SCFAs are explained, and the path to healing and optimizing your gut is revealed.

For those of you who don’t feel so great when eating a plant-based diet, I have an entire chapter on how to handle food sensitivities, as well as a four week plan with more than 75 recipes, laid out in a structured program so that you can gently ease your gut into this newfound healing lifestyle.

I look forward to helping you discover the incredible gut-healing benefits of a Fiber Fueled lifestyle.

Dr. Will Bulsiewicz

Will Bulsiewicz, MD, is a board-certified gastroenterologist in clinical practice in Charleston, SC. He is an internationally recognized gut health expert, a trained epidemiologist, and the author of the new book Fiber Fueled and more than 20 scientific papers. A graduate of Georgetown University School of Medicine, he trained in internal medicine at Northwestern Memorial Hospital and gastroenterology at The University of North Carolina Hospitals. He also earned a Master of Science in clinical investigation (MSCI) from Northwestern University and a certificate in nutrition from Cornell University.

Comments are closed.