3 Reasons Eliminating Grains May Be Harmful For Gut Health

Will Bulsiewicz, M.D., is a go-to source when it comes to questions surrounding gut health. Board-certified in both internal medicine and gastroenterology and published in America's top gastroenterology journals, he's seen hundreds of cases surrounding our most common gut health complaints. Additionally, he earned a Master of Science in clinical investigation (MSCI) from Northwestern University, as well as a certificate in nutrition from Cornell University. When it comes to the gastroenterology and the microbiome, Bulsiewicz is nothing short of a seasoned professional.

Highly processed grains—think white flour, breakfast cereals, and pastries—are definitely the culprits for gas pains and stomachaches. However, those minimally processed, whole grains are on the good side of gluten that Dr. B definitely stands behind. He mentions that although people may experience inflammation or bloating when consuming these whole grains, it's less about what we're eating that causes the reaction and more about the damage already done to our microbiome. 

"There definitely are people having gas, bloating, and some sort of reaction to the consumption of these foods," Dr. B tells me. "But believe it or not, it is not the gluten necessarily. It is actually a component of the grain, which is called a fructan. Fructans are one of the FODMAPs, if you have heard of the low-FODMAP diet. And so for someone who has damage to their microbiome or has underlying irritable bowel syndrome, that's what's going to cause that feeling that they get—the gas, bloating, GI distress—changes in their bowel habits. And it's not necessarily inflammation from grains."

When we eliminate a food group entirely, we're reducing the diversity of our microbiome and making it more susceptible to harmful bacteria. Meaning, our microbiomes become weaker and make us more susceptible to bloating and gas pain.

"When we eliminate grains of any variety, we see that there is a loss of diversity within the microbiome," he adds. "And it makes sense to me, because when we do categorical elimination of plant foods that feed the microbiome in a unique way, then we should expect that all of the bacteria that thrive off the consumption of those foods are going to fall off." 

With not enough of this "good" bacteria, the harmful bacteria overpower the microbiome, which can lead to increased intestinal permeability and inflammation. He asserts that a diverse, plant-based diet is the most important component for a healthy eating plan that will ensure a diverse and strong microbiome.  

Plant-based foods—including grains!—contain fiber, which is essential for a healthy gut microbiome, according to Dr. B. 

"Ninety-seven percent of Americans are not getting the minimal amount of fiber that's recommended to them, which is 25 grams for women and 37 grams for men," Dr. B reveals. Because most of the country is deficient in fiber, our gas, bloating, and leaky gut issues could be a result of this lack of critical bacteria. 

So, cutting grains from your diet could contribute to this lack of fiber, which, in turn, can cause most of our common gut health issues: "Fiber is critical in terms of the microbiome. It feeds the healthy bacteria. They multiply. They thrive. And then what they do is they actually pay us back. They transform the fiber into short-chain fatty acids called butyrate, acetate, and propionate. And these short-chain fatty acids are then released right there in the colon and fix things like leaky gut." 

So for a healthy gut, opt for a diversity of plants—think fruits, vegetables, nuts, and seeds—and don't skip out on the complex carbohydrates, as if you needed another reason to pile on the quinoa.