Imagine a busy city on a weekday morning, with sidewalks packed with people rushing to get to work. Now, imagine this at a microscopic level and you’ll understand what the microbiome looks like inside our bodies. It has trillions of microorganisms of thousands of different species, including not just bacteria but also fungi, parasites, and viruses.

These “bugs” coexist peacefully in a healthy body, in fact, recent research is showing that they influence a lot of bodily processes. They’re also largely influenced by what we eat. Processed and fried food can damage the gut equilibrium, while vegetables and fruits help maintain it. Now, researchers found that adding a daily teaspoon of herbs and spices and an ounce of peanuts to the diet can also have a positive impact on your gut.

Microbiome and diets

“Research has shown that people who have a lot of different microbes have better health, and a better diet, than those who don’t have much bacterial diversity,” Penny Kris-Etherton, a professor of Nutritional Sciences at Penn University, and one of the researchers behind the two new studies on microbiome health, said in a statement.

In their first study, Kris-Etherton and her colleagues compared the effects of snacking 28 grams (one ounce) of peanuts per day versus a higher carbohydrate snack (like cheese bits or pretzels for instance). At the end of six weeks, those who ate peanuts had an increased abundance of Ruminococcaceae — a bacterium linked to healthier liver metabolism.

A total of 50 participants completed the study, with the researchers assessing fecal bacterial diversity. Nuts (including tree nuts, peanuts, and nut butter) are usually recommended as part of healthy dietary patterns. Peanuts are the most consumed nut in the US. But this was the first study to look at their effect on microbiota composition.

In the herbs and spices study, the researchers analyzed the impact of adding blends of herbs and spices (such as ginger, cinnamon, cumin, turmeric, rosemary, oregano, basil, and thyme) to the diets of participants at risk of cardiovascular disease. Herbs and spices have been previously associated with a healthy gut, but not actually investigated.

The researchers looked at three doses — about 1/8 teaspoon per day, a little more than 3/4 teaspoon per day, and about 1 1/2 teaspoon per day. By the end of the four-week experiment, participants had an increase in gut bacteria diversity, including an increase in Ruminococcaceae, especially those eating the highest doses of herbs and spices.

“It’s such a simple thing that people can do,” said Kris-Etherton in a statement. “Everyone could benefit by adding herbs and spices. It’s also a way of decreasing sodium in your diet but flavoring foods in a way that makes them palatable and, in fact, delicious! Taste is really a top criterion for why people choose the foods they do.”

Scientists are still learning about the connection between gut microbiota and a range of health factors, from blood pressure to weight. A lot more research is still needed, said Kris-Etherton. In the meantime, we can all start looking at our diets and think of ways to make changes. It’s never too late to start eating a healthier diet.

The two studies were published in the Journal of Nutrition and the Journal of Clinica Nutrition.