Studies show that our gut microbes convert the food we eat into thousands of enzymes, hormones, vitamins and other metabolites that influence everything from your Mental Health and immune system to your probability of to gain weight and develop chronic diseases.
Gut bacteria can even affect your mental state by producing mood-altering neurotransmitters like dopamine, which regulates pleasure, learning, and motivation, and serotonin, which plays a role in happiness, appetite, and mood. sexual desire. Some recent studies to suggest that the composition of your gut microbiota may even play a role in the quality of your sleep.
But the wrong mix of microbes can produce chemicals that flood your bloodstream and build a plate in your coronary arteries. The hormones they produce can influence your appetite, blood sugar levels, inflammation, and your risk of developing obesity and type 2 diabetes.
The foods you eat, as well as your environment and lifestyle, seem to play a much bigger role in shaping your gut microbiome than genetics. In fact, genes have a surprisingly small effect. Studies show that even identical twins share only a third of the same gut microbes.
Your “good” microbes feast on fiber and variety
In general, scientists have found that the more diverse your diet, the more your gut microbiota. Studies show that a high level of microbiome diversity is correlated with good health and that low diversity is linked to higher rates of weight gain and obesity, Diabetes, rheumatoid arthritis and other chronic diseases.
Eating a wide variety of fiber-rich plants and nutrient-dense foods appears to be particularly beneficial, said Tim Spector, professor of genetic epidemiology at King’s College London and founder of the British Gut Project, a crowd-sourced effort to map thousands of individuals. microbiomes.
Even if you already eat lots of fruits and vegetables, Spector advises increasing the variety of plant foods you eat each week. A quick way to do this is to start using more herbs and spices. You can use a variety of leafy greens rather than just one type of lettuce for your salads. Adding a variety of fruits to your breakfast, adding several different vegetables to your stir-fry, and eating more nuts, seeds, beans, and grains is good for your microbiome.
These plant foods contain soluble fiber that passes through much of your gastrointestinal tract unaffected until it reaches your large intestine. There, gut microbes feast on it, metabolizing and converting the fiber into beneficial compounds such as short-chain fatty acids, which can reduce inflammation and help to regulate your appetite and blood sugar levels.
In one study, scientists followed more than 1,600 people for about a decade. They found that people who had the highest levels of microbial diversity also consumed higher levels of fiber. And they even gained less weight during the 10-year study, which was published in the International Journal of Obesity.
Clusters of ‘bad’ microbes thrive on junk food
Another important measure of gut health is the ratio of beneficial microbes to potentially harmful microbes. In a study of 1,100 people in the US and Britain published last year in natural medicine, Spector and a team of scientists from Harvard, Stanford and other universities identified clusters of “good” gut microbes that protected people against cardiovascular disease, obesity and diabetes. They also identified clusters of “bad” microbes that promoted inflammation, heart disease and poor metabolic health.
While it’s clear that eating lots of fiber is good for your microbiome, research shows that eating the wrong foods can tip the balance in your gut in favor of disease-promoting microbes.
The Nature study found that “bad” germs were more common in people who ate lots of highly processed foods that were low in fiber and high in additives such as sugar, salt and artificial ingredients. This includes soft drinks, white bread and white pasta, processed meats, and packaged snacks like cookies, candy bars, and potato chips.
The findings were based on an ongoing project called the Zoe Predict study, the largest personalized nutritional study in the world. It’s run by a health sciences company that Spector and his colleagues created called Zoe, which allows consumers to have their microbiomes analyzed for a fee.
Add more spices, nuts, herbs and fermented foods to your diet
Once you start increasing the variety of plant foods you eat each day, make it a goal to try eating around you. 30 different plant foods a week, says Spector. It may seem like a lot, but you’re probably already eating a lot of these foods.
The sample menu shows how, in just three meals during the week, you can easily eat 30 different plant foods.
- One day, start your day with a bowl of plain yogurt topped with sliced bananas and strawberries, a pinch of ground cinnamon, and a handful of mixed nuts (containing almonds, pecans, cashews, hazelnuts and peanuts). Meal count: 8 plant foods
- Another day, eat a leafy salad with at least two mixed greens, tomatoes, carrots, broccoli and peppers. Add Herbes de Provence, a seasoning that typically contains six herbs, to grilled chicken or fish. Meal count: 12 plant foods
- Later in the week, eat chicken seasoned with pesto (it contains basil, pine nuts and garlic) and enjoy a bowl of brown rice with onions and kidney beans and a side of sautéed vegetables with green and yellow squash, mushrooms and shallots. Meal count: 10 plant foods
Another way to feed your gut microbiota is to eat fermented foods like yogurt, kimchi, sauerkraut, kombucha, and kefir. The microbes in fermented foods, known as probiotics, produce vitamins, hormones and other nutrients. When you eat them, they can increase the diversity of your gut microbiota and boost your immune health, said Maria Marco, a professor of food science and technology who studies microbes and gut health at the University of California, Davis.
In a study published last year in the cell reviewStanford researchers found that when they asked people to eat fermented foods every day over a 10-week period, it increased their gut microbial diversity and reduced their levels of inflammation.
“We are increasingly developing a very rich understanding of why microbes are so good for us,” Marco said.
Have a question for Anahad about healthy eating? E-mail EatingLab@washpost.com and we may answer your question in a future column.