A doctor says our gut microbiome affects our hormones. He shared 3 things he avoids to stay healthy.

• Hormonal balance is one of the many benefits of having a healthy gut microbiome, a doctor said.
• Dr. Max Nieuwdorp, a hormone specialist, researches how the gut affects our hormones.

A scientist and doctor who researches the role of the gut microbiome in our body's hormonal processes shared three things he avoids for his gut health.

Gut health is a buzzy topic with mounting research finding that a healthy gut microbiome, the trillions of microbes that live in the colon lining, is linked to copious health benefits, from smoother digestion to improved mood and immunity. It's no surprise, then, that the global gut health supplement market has been valued at $12 billion.

In his latest book, "The Power of Hormones," Dr. Max Nieuwdorp, an endocrinologist, internist, and researcher based in the Netherlands, highlights yet another benefit of looking after your gut: hormonal health.

Nieuwdorp writes that gut bacteria play a crucial role in maintaining a healthy hormonal balance. They are involved in the release and production of dozens of different hormones and can influence the brain via the central nervous system, according to his book.

"The microbiome can really talk to the body by producing specific substances from the diet that are good or bad for you," Nieuwdorp told Business Insider. Bacteria and the substances they release during the digestive process can affect the function of hormones, he said.

Hormones are sophisticated substances released from glands that act as messengers throughout the body, Nieuwdorp said. They essentially tell parts of the body to do certain jobs. For example, the pancreas produces the hormone insulin, which allows glucose to enter cells to be used as energy. The adrenal gland, meanwhile, releases cortisol, a stress hormone, to wake us up in the morning.

Other than eating a healthy diet, exercising, easing stress, and sleeping enough, experts don't know what specific lifestyle choices people can make to boost their hormone function yet, Nieuwdorp said.

However, given the strong links between gut health and hormones he has learned of through his research, he's made some lifestyle changes to support his gut health and, in turn, his endocrine system.

Here are three things he avoids for his gut microbiome.

Red meat

Nieuwdorp has cut down on how much red meat he eats. "I try to not eat meat every day," he said.

This is because it changes the composition of the microbiome. When we eat red meat, the bacteria in the gut make "dangerous" metabolites when digesting it, he said.

Experts used to think that the increased cardiovascular disease risk associated with red meat came from the meat's high saturated fat content. But newer evidence suggests it might be linked to this microbiome response, according to 2022 study published in the American Heart Association journal Arteriosclerosis, Thrombosis, and Vascular Biology.

High blood levels of Trimethylamine N-oxide, or TMAO, a metabolite produced by gut bacteria to help digest red meat, may be associated with a higher risk of cardiovascular disease, chronic kidney disease, and Type 2 diabetes, the study said.

Ultra-processed foods

After reading some compelling research on the negative health effects of food processing, Nieuwdorp always checks nutritional labels to see how food has been processed. He tries to avoid ultra-processed foods and eat more fresh foods.

A diet high in UPFs has been linked to an increased risk of many health problems including gut diseases such as inflammatory bowel disease and colorectal cancer. However, the way most nutritional research is conducted makes it difficult to pinpoint whether the UPFs themselves are the cause, although the evidence is compelling.

However, food additives commonly added to UPFs, such as emulsifiers, sweeteners, and colors, appeared to affect the gut microbiome, intestinal permeability, and intestinal inflammation in a 2024 article published in Nature.

Antibiotics

Although antibiotics are crucial for treating infection and save millions of lives every year, they also disrupt the gut microbiome.

Taking a course of antibiotics decreases the number of microbes in the colon, and reduces the diversity of those microbes, according to UCLA Health.

"They drive dysbiosis in the gut," Nieuwdorp. For this reason, he tries to avoid taking them unless absolutely necessary.