Your intestinal tract is home to trillions and trillions of microbes, the vast majority of them residing in your large intestine. Collectively, these bacteria, yeasts and fungi make up what’s called your microbiota.
Your gut microbiota extracts energy and nutrients from fibre, synthesizes certain vitamins, activates disease-fighting phytochemicals, regulates immune function and protects the lining of the gut. Growing evidence suggests this microbial community also plays a role in inflammatory bowel disease, mental health, weight control, even food cravings.
The key to a healthy microbiome is nourishing it by eating the right foods, called prebiotics.
What are prebiotics?
Prebiotics are fibrous, non-digestible carbohydrates that, once consumed, make their way to the colon where they fuel the growth of beneficial, probiotic bacteria (e.g. Bifiodobacteria and Lactobacilli). Feeding probiotic bacteria in the gut is believed to promote better overall health.
Certain strains of probiotic bacteria are thought to to enhance the immune system, treat traveller’s diarrhea, ease lactose intolerance, reduce the severity of inflammatory bowel disease and, possibly, lower the risk of colorectal cancer.
The idea that gut bacteria also play a role in weight control is being increasingly recognized by scientists.
When bacteria feed on prebiotics, compounds called short chain fatty acids (SCFAs) are formed in the process. Certain SCFAs have been shown to increase the release of appetite-suppressing hormones in the gut and reduce calorie intake.
Studies conducted in obese rodents have demonstrated the ability of SCFAs to increase calorie-burning and improve insulin sensitivity.
Foods that feed gut bacteria
The most common type of prebiotics are called fructans, carbohydrates found in artichokes, asparagus, bananas, chicory, dandelion root, garlic, jicama, leeks, onions and whole grains (barley, rye, wheat).
Inulin, a fructan extracted from chicory root, is added to many food products such as breads, pastas (e.g. Catelli Smart Pasta), fruit juices and yogurt to boost fibre content.
Another member of the prebiotic family are galacto-oligosaccharides, or GOS, carbohydrates that occur naturally in breast milk and can also be produced from the milk sugar lactose. Fermented dairy products such as yogurt, buttermilk and kefir contain GOS prebiotics.
6 prebiotics to add to your diet
To keep helpful gut bacteria flourishing, include these foods in your diet – they also deliver important nutrients and phytochemicals. (Prebiotics are not destroyed by cooking.)
High in prebiotic carbohydrates called fructans, asparagus delivers plenty of potassium, vitamin A, vitamin K and anti-inflammatory phytochemicals.
It’s also one of the best food sources of folate, a B vitamin that keeps DNA in cells in good repair. Eight asparagus spears contain almost half a day’s worth of the vitamin (179 mcg). Adults need 400 mcg of folate per day.
Enjoy asparagus steamed, sautéed, grilled or roasted. Add it to stir-fries, pasta dishes, risotto, soups, omelettes, frittatas and vegetable platters.
Not truly artichokes, these small brown-skinned tubers are packed with fructans and potassium, a mineral that helps keep blood pressure in check.
Prepare Jerusalem artichokes like you would parsnips. Enjoy them roasted or sautéed or added them to stir-fries. Puree roasted artichokes with chicken or vegetable stock to make soup.
Or add julienned slices of Jerusalem artichoke to salads and coleslaw.
This inulin-containing root vegetable, cultivated in Central and South America, is a good source of fibre and vitamin C. It also offers small amounts of B vitamins and minerals
Pronounced “hicima”, jicama looks a bit like a turnip although the two vegetables aren’t related.
Its mild flavour and crisp texture make raw jicama a good addition to green salads, bean salads, salsas and crudité. It can also be added to stir-fries or sautéed on its own as a side dish.
In addition to prebiotic galacto-oligosaccharides, kefir serves up a hefty does of probiotic cultures – typically three times the amount found in yogurt. It’s also a good source of protein and calcium.
Drink kefir on its own, pour it over cereal and granola, or blend it with fruit to make a smoothie. Choose an unflavoured product to reduce added sugars.
A milder-tasting member of the onion family, leeks deliver prebiotics along with vitamin A, flavonoids and organosulfur compounds, phytochemicals thought to have anti-cancer properties.
Toss finely chopped leeks into salads. Add sliced leeks to omelettes and frittatas. Stir-fry leeks with other vegetables for a side dish. Stir sautéed leeks into soups and stews for extra flavour.
100 per cent whole wheat, whole grain rye and hulled (dehulled) barley are good sources of prebiotic fibres, protein, magnesium and manganese, a mineral that’s needed for normal brain and nerve function and to regulate blood sugar.
Serve a side of cooked wheat berries, bulgur (a whole grain wheat) or hulled barely as a change from rice or quinoa. When buying rye bread, look for rye berries, whole rye or rye meal on the ingredient list to be sure you’re getting whole grain rye.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.