Your gut health plays a big role in your overall health. That’s because about 70-80% of your immune cells live in your gut, so your gut microbiome influences your overall immune function.
Your gut microbiome is the community of microorganisms (such as fungi, bacteria, and viruses) that live in your gut. Your gut microbiota—the specific microbes in your gut—change in response to factors like diet and exercise.
Your gut also directly communicates with your brain, and vice versa, via the gut-brain axis. This connection means that your brain can influence intestinal activities (such as having nervous diarrhea) and in turn your gut can influence your mood, cognition, and mental health—positively or negatively.
In addition, a weakened gut can allow bacteria and inflammatory substances to be absorbed from your gut into your bloodstream. This can trigger illnesses and full-body inflammation, which is linked to an increased risk of chronic disease.
Therefore, what you feed your gut is crucial to your physical and mental well-being. Here are foods and food groups that maximize the functioning of your gut and its microbiome, and a short list of foods to minimize for optimal gut health.
Pulses support good gut health. In addition to their plant protein and polyphenol antioxidants, pulses contain non-digestible carbohydrates (NDCs), including soluble and insoluble fiber.
NDCs act as prebiotics, which means they serve as food sources for beneficial, health-protective microbes in the gut. When NDCs are fermented by bacteria in the gut, anti-inflammatory compounds called short-chain fatty acids (SCFAs) are produced. Polyphenols from pulses also have anti-inflammatory effects and serve as additional prebiotics.
The anti-inflammatory impact of pulses in the gut has been shown to improve the health of the digestive tract, improving its strength as a barrier between the gut and the bloodstream.
A healthy gut barrier selectively allows beneficial substances into the blood, like nutrients and water. An impaired or weak intestinal barrier can allow harmful substances into your blood circulation that can result in systemic or full-body inflammation, which is linked to illnesses and disease. SCFAs in particular play a key role in maintaining the health of your intestinal barrier.
Pulses include:
Beans
Chickpeas
Dry peas (like split peas and black-eyed peas)
Lentils
Probiotics are live microorganisms that have been shown to help reshape the makeup of your gut microbiota in ways that can enhance your immune function, help reduce obesity and diabetes risk, promote overall wellness, and improve multiple bowel diseases. Probiotics change the gut environment in ways that decrease the ability of harmful bacteria to grow and allow healthful bacteria to flourish.
Probiotics may be found in non-pasteurized fermented foods, such as raw sauerkraut. Multiple studies have shown that microorganisms in fermented foods can survive digestion and reach the colon, where they can help support immune function.
A 2021 Stanford University study assessed 36 healthy adults who were randomly assigned to 10-week diets that included either fermented foods or high-fiber non-fermented foods. Compared to the high fiber eaters, those who consumed fermented foods experienced greater benefits, including positive immune status changes and reductions in levels of 19 inflammatory proteins, including one called interleukin 6, which has been linked to conditions such as rheumatoid arthritis, type 2 diabetes, and chronic stress.
Researchers concluded that the study results suggest that fermented foods may have a powerful impact on immune function and may help combat non-communicable chronic diseases (NCCDs), such as obesity and diabetes, which are largely driven by chronic inflammation.
Probiotic foods may include:
Fermented vegetables
Kefir
Kimchi
Kombucha
Miso
Sauerkraut
Tempeh
Yogurt
Prebiotics help feed probiotic bacteria in your gut by boosting the growth of “good” bacterial strains, including Bifidobacterium and Lactobacillus. They also shift the intestinal pH, which prevents harmful microbes from growing, such as Clostridium perfringens and Escherichia coli.
These changes result in reduced gut inflammation and are thought to increase the production of a hormone called intestinal glucagon like peptide 2 (GLP2), which is known to reinforce the strength of the gut lining. In addition, the fermentation of prebiotic fibers, which leads to the production on SCFAs, has been shown to reduce hunger and improve the post-meal regulation of blood sugar and insulin levels. SCFAs have also been shown to reduce inflammation and have a positive impact on cholesterol regulation.
A typical Western diet, which is typically low in vegetables, fruits, and whole grains, provides only 1-4 grams of prebiotics per day compared to the 5.5-20 grams per day shown to offer benefits in research studies.
Food sources of prebiotics include:
- Asparagus
- Bananas (especially when less ripe)
- Barley
- Chicory
- Garlic
- Jerusalem artichokes
- Leeks
- Onions
- Wheat bran