1. Cook With Garlic, Onions, Shallots, Scallions, and Leeks
Vegetables in the allium family, like garlic, onions, shallots, scallions, and leeks, all contain fructans, a type of prebiotic fiber. Humans lack the enzymes necessary to break down fructans, so they end up in the colon, where our good microbes use them as nourishment and break them down through fermentation. As a by-product, short-chain fatty acids are produced, which are compounds demonstrated to lower inflammation, promote a healthy weight, and improve insulin sensitivity, according to research published in March 2020 in the journal Nutrients. Additionally, short-chain fatty acids make the gut environment more acidic, which increases mineral absorption. By feeding good gut microbes and increasing short-chain fatty acid production, fructans are thought to increase our absorption of calcium and improve bone density, according to research published in February 2021 in the International Journal for Vitamin and Nutrition Research.
Alliums also stimulate the growth and activity of beneficial gut bacteria, such as lactobacillus and bifidobacterium, while decreasing the growth and activity of harmful bacteria, as outlined in a review published in August 2021 in the journal Foods. These gut microbiome shifts may help ward off chronic disease like inflammatory bowel disease and obesity.
To add more alliums to your meals and reap the benefits of fructans:
- Cook with a generous amount of sauteed garlic and onion.
- Add leeks to soups and stews.
- Sprinkle sliced scallions onto salads and stir-fry dishes.
- Season with garlic and onion powder. (When selecting a garlic or onion powder, look for brands containing only dehydrated garlic or onion, to reap their full benefits and avoid consuming unnecessary additives.)
2. Blend Underripe Bananas Into Smoothies
While it may sound strange to seek out underripe bananas instead of ripe ones for your morning smoothie, underripe bananas are actually higher in prebiotic fiber compared with their ripe counterparts, according to research published in 2021 in the journal PLoS One. Underripe bananas contain resistant starch, a type of starch that resists digestion in our upper gastrointestinal tract and then makes its way to the colon, where it acts as a prebiotic to selectively feed good gut microbes. As a banana ripens, this resistant starch is converted into simple sugars, which do not have the same prebiotic effects.
Resistant starch consumption may also aid in weight management and obesity prevention due to its positive influence over the gut microbiome, as well as its ability to promote satiety and stable blood sugar levels, according to research published in June 2019 in the journal Nutrients.
To start your day with a healthy dose of prebiotics, try making a flavorful morning smoothie by blending a frozen, slightly underripe banana with plain Greek yogurt, 1 tablespoon each of peanut butter, chia seeds, and cacao powder, a date for sweetness, and just enough unsweetened almond milk to blend.
It is worth noting, however, that if you are allergic to latex, you may need to avoid consuming underripe bananas, which contain proteins with a similar structure to latex and may provoke an allergic reaction in susceptible individuals.
3. Add Chia Seeds and Flaxseed to Yogurt, Oatmeal, and Smoothies
Chia seeds and flaxseed are best known for their nutrient density, but they also happen to be excellent sources of prebiotics. Research published in June 2019 in the journal Nutrients demonstrates that chia seed consumption is linked to reduced markers of inflammation in those with type 2 diabetes, and their prebiotic fiber content likely plays a role.
Flaxseed, on the other hand, may reduce risk for certain cancers, including breast cancer, according to a review published in May 2019 in the journal Nutrients. Study authors attribute this to the lignan content of flaxseed. Lignans, which are a prebiotic, are fermented by good gut microbes and, through the fermentation process, transformed into compounds that are linked to both reduced breast cancer risk and decreased breast cancer mortality.
Both chia seeds and flaxseed may lend a slight nutty flavor to foods. To compliment this, sprinkle them over fruit such as berries on top of yogurt or oatmeal, or blend with a banana into a smoothie. Additionally, chia seeds may change the consistency of foods due to their high soluble fiber content, which forms a viscous gel when exposed to moisture. You can take advantage of this gelling property by using it to thicken your oatmeal, making it more filling. When added to yogurt, chia seeds form a consistency similar to rice pudding — just add flavoring of your choice, such as cinnamon, vanilla extract, and a drizzle of honey, for a delicious chia seed pudding.
4. Swap Meat for Beans and Legumes a Few Times a Week
Beans and legumes such as chickpeas, black beans, and lentils are not only excellent plant-based proteins, they’re also rich sources of a type of prebiotic fiber called galactooligosaccharides (GOS). According to research published in March 2021 in the journal Biomolecules, this specific type of prebiotic fiber increases beneficial bifidobacteria in the gut, which have been studied for their ability to improve the blood lipid profile, as outlined in research published in 2019 in Jornal Vascular Brasileiro. Additionally, a clinical trial published in January 2022 in the journal Nutrients demonstrates that GOS can improve constipation in adults, likely as a result of increasing bifidobacteria in the gut.
Incorporating a few plant-based meals featuring beans and legumes into your weekly rotation can do wonders for your health. In fact, a study of over 40,000 U.S. men published in 2020 in the British Medical Journal, demonstrates that replacing meat with plant-based proteins such as prebiotic-rich beans and legumes reduces risk for coronary heart disease.
Try whipping up a vegetarian chili incorporating a few bean varieties, experiment with black bean tacos, use lentils in a Bolognese sauce, or prepare baked falafel with chickpeas. You can also increase the prebiotic content of any of your favorite recipes by swapping out some or all of the meat for an equal volume of beans and legumes.
5. Satisfy Your Sweet Tooth With Dark Chocolate
As if we need another reason to eat chocolate, cocoa contains polyphenols, naturally occurring antioxidant compounds that are poorly digested by our bodies but fermented by our good gut microbes. Research published in June 2020 in the journal Nutrients demonstrates that cocoa polyphenols increase beneficial gut bacteria like lactobacillus and bifidobacterium while decreasing harmful bacteria like Clostridium perfringens. These gut microbiome shifts are associated with reductions in inflammation and enhanced immune function.
Not all chocolate is equal, however. The higher the percentage of cocoa that chocolate contains, the more potent its prebiotic effects. Opting for a dark chocolate bar with a cocoa content of 70 percent or greater is your best bet when it comes to fostering a healthy gut microbiome.
