There’s no question that modern, processed diets are bad for your gut. Because of the vast majority of agricultural subsidies that go to producers of corn, wheat and soy, the prices of the foods containing these plants (many of which are high in sugar and refined carbohydrates and poor in vitamins, minerals, micronutrients and contain fiber) have gone down – they’re cheap and easily available to consumers.
Dietary fiber – found in vegetables, fruits, and a variety of whole grain products – promotes the microbial biodiversity of the intestine and nourishes beneficial bacteria in the digestive tract. In fact, these “good” bugs use fiber to make gut-healthy, anti-inflammatory compounds called short chain fatty acids (SCFAs). But the average American is only getting 15 grams of fiber a day while we should be getting at least 25 to 30 grams. “Part of the problem we see today could be due to three to four generations of progressively reduced fiber consumption,” says gastroenterologist Will Bulsiewicz, MD, author of Fiber-powered, Referring to a groundbreaking 2016 study in nature by Stanford University microbiome researcher Justin Sonnenburg, Ph.D.
For the study, the researchers fed mice on a low-fiber diet for several generations. After a generation, there was a decrease in microbial biodiversity in the gut, which was reversible when foods rich in fiber were resumed. But with each successive generation there was a progressive loss of biodiversity that was more difficult (and impossible) to reverse Completely turning back).
“Compared to the Hadza in Tanzania, some of the last remaining hunter-gatherer communities, people in the US have about 40% less microbial diversity in their gut,” says Bulsiewicz. “This leads us to believe that we have essentially lost 40% of what we should have as humans. It is reversible to some extent, but this study shows that we may be in a place where we are impaired from the start. “-Walk.”
Excessive consumption of animal products (especially in the absence of high-fiber foods) can also have a negative effect on the intestinal microbiome. This was illustrated in a 2014 study by Harvard researchers that put the same group of people on two drastically different diets – an animal-based diet containing foods like bacon, eggs, salami, and pork skin; and a vegan diet with foods like rice, tomatoes, lentils, squash and fruits – and the effects of each one measured. What they found: In animal nutrition, there was a significant increase in bile-tolerant intestinal microbes, which are necessary for fat breakdown, but are also associated with inflammatory processes.
In addition, excessive consumption of refined carbohydrates and sugars has been shown to decrease microbial biodiversity and feed bad microbes. “Someone who eats way too much sugar becomes fertile ground for yeast to grow in their gut,” says Vincent Pedre, MD, integrative physician and author of Happy good.