You probably know about probiotics, the friendly bacteria in your gut that promote good health. But you may not know much about prebiotics, the nutritional compounds in your diet that are the food supply for probiotics. Getting more prebiotics into your daily diet is one of the most important actions you can take for better health and healing.
Your colon is the primary home of a complex ecosystem of 100 trillion bacteria collectively called the gut microbiome. Many of those hundreds of species of bacteria are probiotics—friendly, health-giving bacteria that aid digestion, strengthen the immune system, improve metabolism, and energize the brain. Other gut bacteria are unfriendly and health-threatening, like C. difficile, which can multiply after the use of antibiotics, causing diarrhea, stomach cramps, kidney damage, and, in the most severe cases, death.
When unfriendly gut bacteria dominate the gut microbiome, you have a condition called dysbiosis—an intestinal imbalance that sparks chronic inflammation throughout the body.
Scientific research shows that dysbiosis plays a key role in causing or contributing to many inflammation-linked conditions and diseases, including high blood pressure, cardiovascular disease, type 2 diabetes, autoimmune disease, asthma, allergies, glaucoma, depression and anxiety, and cognitive decline.
Prebiotics are the food for the microbiome. Having more prebiotic-rich foods in your diet can prevent or clear up dysbiosis—making them one of your best nutritional tools for preventing, treating or reversing inflammation-based health problems.
The probiotics in your gut are picky eaters, with a diet that consists mainly of fiber (like the inulin found in asparagus, chia seeds, and bananas), unrefined carbohydrate (like the oligosaccharides found in kale and pears), and polyphenols (like the colorful chemicals found in blueberries and tomatoes). When these compounds reach the colon, they are gobbled up by the gut microbes. Simultaneously, the plant polyphenols and other colorful substances in food decrease inflammation and signal our genes that all is well. As the well-nourished probiotics grow and thrive, they generate short-chain fatty acids (SCFAs)—a biochemical superstar that nourishes the health of the gut, cooling chronic inflammation throughout the body. There are three main SCFAs: butyrate, propionate, and acetate:
A scientific paper published in Advances in Immunology summarizes the importance of SCFAs: “Given the vast effects of SCFAs, and that their levels are regulated by diet, they provide a new basis to explain the increased prevalence of inflammatory disease in Westernized countries.”
In other words: Eat more prebiotic-
rich foods if you want to reduce inflammation and be healthier.
The most effective way to balance the gut microbiota and generate plenty of SCFAs is with prebiotic-rich whole foods. On the other hand, ultra-
processed foods, with added sugar, salt, fat, starches, and artificial colors, flavors, and preservatives, cause dysbiosis.
Fortunately, a wide variety of foods supply prebiotics: artichokes, asparagus, avocados, bananas (under ripe), barley, beet root, bran, burdock root, chia seeds, chicory, Chinese chives, cocoa, cottage cheese, dandelion greens, eggplant, flax seeds, fruit, garlic, green tea, honey, Jerusalem artichokes, jicama, kefir, leeks, legumes, lentils, maple syrup, nuts and seeds, onions, peas, plantains, potatoes, radishes, root vegetables, rye, sea vegetables, soybeans, herbs and spices, sweet potatoes, tomatoes, vegetables, Yacon root, yams, and yogurt.
Choose the foods from the list that you like, and eat seven to eight servings a day. But don’t start eating all those servings tomorrow. Most of these foods are fiber-rich, and the gut does best slowly adjusting to a higher intake of fiber.
To avoid gas and bloating, start with two to three servings daily. Add one to two servings per week, taking two to three weeks to reach eight daily servings. Each day, try to get one to three tablespoons of fresh (or one to two teaspoons of dried) herbs and spices. For example, you could grow mint on the windowsill and drink mint tea daily. Or add rosemary, thyme, sage, or parsley to stews, casseroles, and soups. Put a sprinkle of cinnamon on your oatmeal. Make a smoothie with ginger and fresh turmeric.
There’s plenty of evidence that these prebiotic-rich foods are doing their job. One scientific study showed that dandelion greens stimulated the growth of 14 strains of probiotics. Scientists at Louisiana State University Health Sciences Center found that walnuts increased the diversity of probiotics like Lactobacillus. Researchers at the University of Massachusetts Amherst found that xyloglucan—a prebiotic in cranberries—is a favored food of bifidobacteria, a probiotic.
“We already know we have beneficial microbes in our guts, so let’s feed them,” said David Sela, PhD, the lead researcher in the cranberry study. “Let’s give them the things that they like.”
Prebiotics are available in supplement form, often packaged with probiotics in a supplement called a synbiotic. But supplements aren’t the best way to get your prebiotics. That’s because the prebiotics found in supplements are extracts from food—compounds like fructans, galacto-oligosaccharides, and glucose-derived oligosaccharides. While helpful, they don’t supply the diversity of prebiotics you get when you eat a variety of food. For example, ginger delivers more than 300 bioactive compounds. Which of these are the best to help feed probiotics and balance the gut microbiome? No one really knows. It’s far better to rely on food itself to supply your body with the prebiotics it needs.
However, some health conditions may benefit from targeted supplementation with a synbiotic supplement. Nearly 1,000 clinical studies have been conducted on the power of prebiotics to heal disease. Studies conducted in just the last year show that prebiotics (often in a synbiotic supplement) can improve three common conditions:
Parkinson’s disease. Researchers from Rush University Medical Center in Chicago treated 20 Parkinson’s patients—10 newly diagnosed and not on medication and 10 who were receiving medication—with prebiotics. After 10 days, the study participants had less dysbiosis (a characteristic of Parkinson’s disease, according to the researchers), more SCFAs, less inflammation, and lower levels of a protein biomarker for neurological damage. They also had less severe symptoms of the disease.
Irritable bowel syndrome (IBS). This digestive problem affects an estimated one in seven Americans, with symptoms including constipation and/or diarrhea, abdominal pain and cramping, bloating, flatulence, depression, and lower quality of life. In a study published in Gut and Liver, researchers gave 67 IBS patients either a synbiotic (a combination of probiotics plus prebiotics) or a placebo. After four weeks, those taking the synbiotic had significantly less abdominal pain and more psychological well-being than the placebo group.
Stress. Chronic stress can cause a wide range of physical and mental health problems. In a study published in Molecular Psychiatry in February 2023, researchers studied 45 people, dividing them into two groups. One group was given a diet rich in prebiotics and probiotics (fermented foods), and the other ate their standard diet. After four weeks, the group eating the prebiotic/probiotic diet had a 32 percent reduction in perceived stress, compared with a 17 percent reduction in the control group.
Studies from the past year show many health problems can be improved by increased prebiotic or synbiotic intake:
