What is a prebiotic diet? Though this question would not likely have been asked of Hildegard of Bingen medicine, Hildegard of Bingen herself could not have overstated the importance of healthy digestion. In our posts on probiotics and digestion and intestinal health we covered the digestive process and the role of “good” gut bacteria in overall health. Now, a little about prebiotic foods.
Prebiotic Diet for Gut Health
A prebiotic diet includes healthy foods that possess properties to encourage the natural growth of beneficial gut bacteria. Foods with these qualities are called Prebiotics, as opposed to foods (or supplements) that actually contain the live bacteria strains, which are called Probiotics. For a list of healthy foods that contain probiotics, see Fermentation for Health Foods.
Aside from their high nutritional content, the probiotic foods on our list all contain substances that support natural gut flora by either directly or indirectly encouraging bacterial blooms in the beneficial strains of gut bacteria. When in doubt, the primary benefit usually comes down to the presence of fiber.
8 Prebiotic Diet Foods
Most of these foods are readily available year-round – and taste great. So there is no reason to keep those tummy bugs underfed. Get your gut health on track with these seven prebiotic foods.
1. Jerusalem artichokes
Prebiotic Diet Qualities: High in inulin.
Inulin is an insoluble fiber (carbohydrate), which means it does not attract or react to water, thus survives primary digestion largely intact. It travels through the large intestine into the colon where the bacteria there feed on it, reproduce, and release important enzymes that help protect the digestive tract.
The artichoke is an odd plant, in that it is 80% carbohydrate, in the form on inulin. It has very little protein, but also very little starch and no oil. Over time, the inulin will convert into its component, fructose, so it often has a slightly sweet taste.
Note: Jerusalem artichokes may cause some digestive distress to people with sensitive digestive tracts, so it is advisable to consume small amounts at first.
Prebiotic Diet Qualities: Good source of inulin, potassium and magnesium content may reduce inflammation.
Bananas are great sources of potassium, magnesium, B vitamins, and some Vitamin C. The fibrous quality of bananas helps to soothe the gut membrane, but these natural fibers also promote good bacteria growth. Unfortunately, the high starchy fiber content is why they may cause some mild digestive distress. As bananas ripen, however, the starchy fiber is converted to sugar, which makes for easier digestion, so if you are sensitive, choose more ripe ones.
3. Cruciferous vegetables (Broccoli, Kale, Cabbage, Cauliflower)
Prebiotic Diet Qualities: Glucosinolates.
Cruciferous vegetables are part of the Brassica genus of plants, which includes common plants like cauliflower, broccoli, cabbage, arugula, Brussels sprouts, and kale. These vegetables are high in vitamins, minerals, and fiber, but also contain sulfur-containing metabolites, known as glucosinolates.
In the digestive tract, bacteria break glucosinolates down, which releases other bioactive compounds that have been shown to inhibit the growth of cancer. Glucosinolates are also anti-inflammatory.
Prebiotic Diet Qualities: Fiber, short-chain fatty acids (SCFA) that strengthen your intestine cells, improve absorption of micronutrients, and help with weight loss.
Beans are nutritionally dense. They are high in fiber, protein, B vitamins, and folate. The high fiber content of beans provides an ideal food source for the healthy gut bacteria, which break down the carbohydrates into component parts, including short-chain fatty acids that our body uses for many important functions, including boosting your immune response.
5. Allium Vegetables: raw garlic, raw onion, leeks, and scallions.
Prebiotic Diet Qualities: High in inulin and sulfur compounds.
Allium is derived from the Greek word for garlic. Onions, leeks, shallots, and chives are also members of the allium family. Allium vegetables are high in beneficial organo-sulfur compounds, which are what gives them their distinctive flavor and aroma, but are also what makes them anti-inflammatory, anti-cancer, and protective against cardiovascular disease. They are also a great source of inulin and antioxidants.
Garlic is also high in allicin, which is naturally antimicrobial, so garlic not only promotes good bacteria growth but also helps eliminate “bad” microbes.
Prebiotic Diet Qualties: Fiber, polyphenols.
Blueberries are a superfood, which means they are already well known for their dense nutritive and anti-oxidant qualities. In fact, they are one of the highest anti-oxidant foods available. Blueberries are rich in polyphenols, which have an antimicrobial and antioxidative effect. These unique, beneficial compounds have shown to have neuro-protective, anti-inflammatory, and anti-aging properties. They are also good for your skin, and enhance immune function.
The Fiber in blueberries have been shown to enhance the digestive flora. Research out of Sweden indicated that the fiber contained in blueberries could even alleviate and protect against intestinal inflammations, such as ulcerative colitis.
7. Corn Polenta
Prebiotic Diet Qualities: Fiber
A staple of northern Italy, this coarsely ground cornmeal can be a great way to bolster your gut flora and get B vitamins, vitamin A, and fiber. While we wouldn’t typically promote corn due to its overrepresentation in the western diet, in the case of prebiotic benefits, this high-fiber, complex carbohydrate has a fermentable component that many different strains of healthy bacteria consume.
The insoluble fiber in polenta travels directly to the colon, where multiple strains of bacteria ferment it into enzymes, sugars, and other beneficial compounds.