A healthy gut plays an important role in maintaining a strong immune system and preventing disease. Otherwise known as the microbiome, your gut contains millions of bacteria and other microbes that can influence your health in complex ways. The key to maintaining a healthy gut microbiome is to balance the ratio of good bacteria and bad bacteria.
According to the esteemed scientific journal Microorganisms, the right balance is different for every individual, as each person maintains their own personal microbiome profile that is influenced by many factors, including birth gestational date, type of delivery, methods of infant milk feeding and the weaning period. Additionally, there are several other influences on the health of your microbiome, including antibiotic usage, what microbes are currently inhabiting your gut, exercise, diet, and other lifestyle choices.
According to the scientific journal Nutrients, the foods you eat have a direct impact on the makeup of the bacteria in your gut. A healthy gut microbiome can help mitigate the effects of chronic diseases like heart disease and cancer, while reducing inflammation, keeping your brain healthy and helping you maintain a healthy weight. Various studies have also concluded that a healthy microbiome can even help people cope with depression and anxiety.
For those individuals interested in making an immediate dietary change, switching from a mostly animal-based diet to a mostly plant-based diet (and vice versa) can alter the makeup of your gut microbiome in as little as 24 hours. In short, to improve your gut microbiome: eat more probiotics, prebiotics, fiber, polyphenols and fermented foods and eat less artificial sweeteners, red meat, processed foods and alcohol. Below, we break down each category of food and endeavor to explain the role and effects of each.
Probiotics & Gut Health
Probiotics are beneficial (good) bacteria that are commonly found in fermented foods like sauerkraut, kimchi, miso and yogurt. Eating foods that are naturally abundant in probiotics introduces good bacteria to your gut. The most common examples of good bacteria are Lactobacillus and Bifidobacterium. In addition to balancing your gut bacteria and helping prevent chronic disease, probiotics can help relieve the effects of diarrhea, boost your immunity and keep your heart and skin healthy.
Sauerkraut is a simple food, comprised of cabbage and salt. During the fermentation process, microorganisms digest the sugar present in cabbage and produce carbon dioxide and acids. The probiotics created during fermentation process assist with digestion and introduce good bacteria to your gut microbiome. One cup of raw cabbage provides 36% of the recommended daily intake of vitamin C, and 56% of the recmmmended daily intake of vitamin K. Sauerkraut is a hihgly versatile food that can be enjoyed on a sausage or hot dog, it can be substituted for pickles on a sandwich or hamburger, it can be added to potato salad, or you can put it on a cheese plate and serve it to your friends and family.
Kimchi, another type of fermented cabbage, is the spicy Korean alternative to sauerkraut. Often times, it can have scallions, radishes and shrimp added to it to give it more intense flavor. It can be found in the refrigerated section at your local grocery store near the sauerkraut, other Asian sauces and pickled vegetables. Kimchi is especially delicious when added to a fried rice bowl, along with with vegetables and a scrambled egg.
Kefir is not unlike a drinkable yogurt. Kefir is produced when kefir grains (colonies of yeast and lactic acid bacteria) ferment the sugars found in milk, resulting in a slightly thicker consistency and a rather tart flavor. Similar to yogurt, kefir is jam packed with healthy probiotics. It is recommended to buy plain kefir (rather than flavored kefir) to avoid added sugars, or you can make your own kefir at home. Due to the fermentation process, kefir has a slightly tart and acidic taste, which makes it a flavorful addition to a healthy breakfast smoothie. Alternately, you can try substituting kefir for milk when making overnight oats for a healthy combination of probiotics and fiber.
Kombucha is a tart, fizzy tea made by adding a symbiotic colony of bacteria and yeast (SCOBY) and sugar to green or black tea, which is then fermented for a week or two. During fermentation process, alcohol and gases are produced, giving the kombucha it’s natural carbonation. The amount of alcohol in kombucha is generally less than 0.5% alcohol by volume, but some homemade kombucha’s have been found to have closer to 2-3%. To keep the alcohol levels low in your homemade kombucha, make sure to keep it refrigerated and shorten the fermentation time. You could also try making kombuncha with a different type of tea. One study in the scientific journal Nutrients determined that kombucha made with rooibos tea had lower levels of ethanol (which is a type of alcohol) and acetic acid concentrations compared with kombucha produced with black or green tea. Additionally, kombucha made from green tea has the added benefit of various antioxidant properties. Keep in mind that some kombuchas, like those made from black tea, do contain caffeine, while others have artificial sweeteners which can negatively alter gut bacteria, so we recommend reading the labels closely or making your kombucha at home.
Miso is a fermented paste derived from soybeans, barley or rice. Similar to other fermented foods, beneficial (good) bacteria are produced during the fermentation process. You’ll also get some protein in yoour diet if you consume miso made from soybeans. If you’re cooking woith miso, a little bit goes a long way, as miso is high in sodium. Miso is great when added to sauces, dressings and soup bases, or you can try it on Miso Maple Salmon.
Tempeh is similar to tofu in that it’s made from soybeans. However, unlike tofu, tempeh is a fermented food, so it contains a high concentration of probiotics. Tempeh is made when soybeans are fermented and then pressed into a cake, after which it can be grilled, sautéed or baked. Tempeh is also high in protein, making it a viable option for vegetarians and vegans. It’s also packed with vitamin B, calcium, manganese, zinc and copper. Consider marinating and then grilling tempeh, or you can add it to a salad, or even make a tempeh grain bowl.
Yogurt is hands-down the most popular probiotic, and for good reason. It’s made when good bacteria is added to milk, where it metabolizes lactose to form lactic acid and other beneficial microbes. At the grocry store, look for yogurt that includes live and active cultures which contains upwards of 100 million probiotic cultures per gram. A quick review of the ingredients list will show you if there are bacteria in the yogurt. Also note, the probiotics in yogurt help digest some of the lactose (milk sugar) in your gut, so if you’re lactose-intolerant, you may be able to consume yogurt and kefir. Additionally, many companies now produce dairy-free and vegan yogurts that contain high concentrations of probiotics.
Prebiotics & Gut Health
Once good bacteria has become more established in your gut microbiome, you’ll need to feed them so they can flourish and continue producing more and more good bacteria. Prebiotics, fibers that feed the beneficial probiotics in your gut, include galactooligosaccharides, fructooligosaccharides, oligofructose, chicory fiber and inulin. Fructans and cellulose are two other imortant prebiotic fibers, but don’t get caught up in the scientific names, as you won’t most of these compounds listed on food labels. This is because they are present in foods like fruits and vegetables, which do not have labels. Instead, focus on a variety of whole foods by eating plant-based foods as often as possible and ensuring that you ingest the recommended 30 grams of fiber each day. The best probiotic foods include apricots, dried mango, artichokes, leeks, almonds, pistachios and legumes. Additionally, polyphenol-rich foods such as blueberries, strawberries, prunes, apples, flaxseed, olives and extra-virgin olive oil, are very high in prebiotics.
Commonly known as Jerusalem artichokes, this tuberous vegetable isn’t an artichoke at all. Rather, this veggie is part of the sunflower family, also known as sunchoke, sunroot, or wild sunflower, with an appearance similar to ginger root. One cup of Jerusalem artichokes contains 3 grams of protein, 2.5 grams of fiber, 25% of the recommended daily intake of thiamin, and 28% of the recommended daily intake of iron, according to the USDA. According to the esteemed publication, Annals of Agricultural and Environmental Medicine, over 80% of the carbohydrates in sunchokes is comprised of inulin, a prebiotic fiber that provides a source of food for the good bacteria in your gut. Jerusalem artichokes are also a good source of Thiamin, a B vitamin that supports healthy hair, skin and nails, and iron whoch helps form red blood cells. Try roasting sunchokes with olive oil and garlic or you can eat them raw in a leafy green salad.
Leeks are very high in fructans, which are very important for optimal gut health. One cup of leeks has 35% of the recommended daily intake of vitamin K and 12% of the daily recommended daily intake of vitamin C. Vitamin K plays an important role in blood clotting, and vitamin C is a well-known and effective antioxidant. Leeks can be added to almost any recipe, so consider adding them to an omelet or sauteing them to mix with roasted potatoes. Alternatively, you can rub whole leeks with oil and grill them ever-so-briefly, then toss them with your favorite vinaigrette. Oven-braised Leeks are delicious and simple to make, requiring only 15 minutes of preparation.
Onions are an excellent source of natural insulin, fructans and fructooligosaccharides. Fructooligosaccharides are an important prebiotic that aids in the development of gut flora, but they can also help to improve a number of health conditions, including diarrhea, osteoporosis, atherosclerosis, gastrointestinal disorders, cardiovascular disease and type 2 diabetes. Onions are a highly versatile vegetable that can be used in almost any meal; they can be added to soup or salad, they can be grilled and put on top of a hamburger or veggie burger, or they can be roasted with herbs and served as a side dish.
Per the USDA, one cup of raspberries contains an impressive 8 grams of fiber, about one-third of the daily recommended intake. Raspberries are also an excellent source of polyphenols, which are potent antioxidants that your gut microbes love to consume. According to the academic journal, Neural Regeneration Research, polyphenols act as prebiotics by enhancing the growth of beneficial bacteria and inhibiting the growth of pathogens. Raspberries are delicious when eaten fresh, but are equally nutritious when purchased frozen and tossed into a smoothie or bowl of yogurt, oatmeal or your favorite high-fiber cereal.
Beans and Legumes
Many people avoid eating beans for fear of farting, but flatulence is a sign that your gut bacteria are hard at work. When beans and legumes, such as black beans, chickpeas, peas, lentils and white beans, reach the large intestine, they are generally still intact. It’s in the large intestine, or colon, that gut bacteria feed on beans and legumes, and (as you know) this process is called fermentation. And what is the byproduct of fermentation? Yes, that’s right; gas. While experiencing gas may be uncomfortable and awkward, you can feel ok about it because it’s a sign that your gut microbes are hard at work and doing what they’re supposed to. Canned beans are a highly versatile food that can be used to make a simple three-bean salad, or you can add black beans on top of your favorite tacos. Lentils are also highly nutritious and they are delicious in soups. Dried lentils take only 15-20 minutes to cook, and they make for a quick and easy addition to your favorite soups and stews.
Asparagus is a powerful prebiotic for the gut microbiome, due to the presense of fructans, insulin and fructooligosaccharides. According to a recent study in the journal Metabolites, asaparagus is also a source of antioxidants, which are natural chemicals that fend off free radicals and other inflammatory compounds. Roasted asparagus takes just 15 minutes to cook. Simply toss the asparagus spears in olive oil, salt and pepper and roast at 400°F for 10-15 minutes. Alternately, you can enjoy raw asparagus over a leafy mixed green salad. Asparagus is also delicious and nutritious when added to pasta or an omelet.
Garlic has been known to help reduce the risk of heart disease, due to it’s anti-inflammatory properties. Insulin and fructooligosaccharides are the two primary fibers in garlic, providing a powerful prebiotic combination. According to the scientific journal Antioxidants, garlic also has shown great promise in the treatment and management of cancer, cardiovascular disease, metabolic disorders, blood pressure and diabetes. This is due, primarily, to it’s antioxidant, anti-inflammatory and lipid-lowering properties. Garlic has a powerful taste and smell, and it can be used to season almost any dish you can imagine, so feel free to saute it with onions and mix it into your favorite stir-fry or pasta dish.
Green bananas (Yes, the unripened ones) are very good for gut health because they contain resistant starch, a type of indigestible fiber that increases the production of beneficial bacteria when your gut microbes feed on it. Resistant starch can also be produced by cooking grains and allowing them to cool before eating them, due to a naturally-occurring process called retrogradation. Ripe bananas are an excellent source of fiber too, so you can enjoy bananas with peanut or almond butter for a tasty snack high in protein, healthy fat and fiber. You can also add them to overnight oats, greek yogurt or your favorite high-fiber cereal.
Pears are a prebiotic fruit that is really good for the gut microbiome, but they also contain pectin, a compound that is known to lower cholesterol. One medium-sized pear is roughly 100 calories, but it contains over 5 grams of fiber. You can add a dash of cinnamon to fresh pear slices for a tasty snack, you can bake a pear crisp, or you can mix diced pear pieces into oatmeal for additional cholesterol-lowering benefits, thanks to the beta-glucan fiber in the oatmeal.
Watermelon is a delicious fruit that is naturally high in fructan. One cup of this tasty, juicy fruit has 14% of the daily recommended intake of vitamin C, an antioxidant that fights inflammation, provides the building blocks of collagen (for healthy skin) and helps increase your body’s absorption of iron. While watermelon is a summertime favorite that is tasty on its own, you can also make a refreshing beverages with it, or mix it with feta cheese and mint leaves for a fresh, summer salad.
Polyphenols are a type of plant chemical that gut microbes thrive upon, and they can be found in berries, apples, artichokes, onions, tea, chocolate and many other fruits and vegetables. Gut bacteria feed on polyphenols and produce beneficial substances, which can have a positive effect on a number of health conditions, including cancer, diabetes, cardiovascular diseases, and the effects of old age.