For many people, excess weight creeps on slowly.
While the usual culprits – too much food, too little exercise – account for most weight gain, research suggests that a diet lacking prebiotic-packed foods can also contribute to excess pounds over time.
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).
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).
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.
For the new study, published in November 2015, Spanish researchers followed 8,569 normal weight adults, average age 37, for nine years to evaluate the link between prebiotic consumption and the risk of becoming overweight.
People with the highest intake of prebiotics – both fructans and GOS – were significantly less likely to become overweight over time than those who consumed the least, even after adjusting for diet and lifestyle factors related to weight gain (e.g. physical activity, sleep hours, daily calorie intake, fast food consumption).
Evidence mounting that gut bacteria linked to weight control
These findings suggest that eating more prebiotic-containing foods can mitigate adult weight gain, presumably by altering the composition of gut bacteria.
These results add to other research findings suggesting a connection between the foods you eat, your gut microbiota and body weight. Studies have shown that eating a diet low in fibre and high in fat and refined carbohydrates disrupts the make-up of gut bacteria in favour of weight gain.
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.
While more studies are needed to confirm the role of prebiotic-rich foods in weight regulation, there’s no reason not to add these nutritious foods to your diet.
6 nutrient-dense foods that feed “good” gut bacteria
The following foods contain prebiotics, non-digestible fibres that feed beneficial probiotic bacteria in the colon. 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.