Did you know that if your gut is in a rut, chances are your health is out of sorts, too?

The gut, also known as the gastrointestinal (or GI) tract, hosts trillions of bacteria that can have profound effects on digestive health and overall wellness, which is why it’s a good idea to consume prebiotics and probiotics—dietary dynamos that work in concert to populate the gut with “microflora” that keep you healthy.

Eating a variety of prebiotic-rich vegetables and probiotic fermented foods every day may improve mood, reduce cholesterol and promote weight loss. Martina M. Cartwright, PhD, RD, adjunct faculty member at the University of Arizona and biomedical consultant, author and nutrition counselor, sheds light on this topic.

Prebiotics: Fuel for Your Flora

Prebiotics are naturally occurring nondigestible carbohydrates, or soluble fibers, that nourish the growth of specific beneficial bacteria. All prebiotics are fiber, but not all fibers are prebiotics. When prebiotics ferment in the intestines, they release fuel that enables friendly bacteria like Lactobacilli and Bifidobacteria to thrive.

The most common prebiotics are in the inulin-type fructan family. About 5–8 grams a day of inulin prebiotics is enough to support growth of all Bifidobacteria species (Slavin 2013). The health benefits of prebiotics are still being investigated, but studies suggest they can

  • reduce the prevalence and duration of infectious, traveler’s and antibiotic-associated diarrhea (Slavin 2013);
  • reduce inflammation and symptoms of inflammatory bowel disease (Slavin 2013); and
  • protect against colon cancer (Slavin 2013).

Probiotics: Alive and Well

Probiotics are live, active bacteria and/or yeasts. The most common strains of probiotic bacteria are the Lactobacillus and Bifidobacteria families, which use lactose to prevent harmful bacteria growth, compete with bad bugs for nutrients, and alter intestinal pH to tackle bacterial villains (like diarrhea-producing Clostridium difficile) that thrive in a neutral pH environment. Friendly bacteria also stimulate the immune system (Sommer & Bäckhed 2013).

Weight loss and prevention of obesity are linked to consumption of probiotics (Million et al. 2013). Beneficial bacteria may also improve athletic performance (West et al. 2009) and reduce anxiety (Tillisch et al. 2013).

What to Eat

Prebiotic Foods

These foods are the richest in prebiotics. The lead-in has the percentage of prebiotic fiber by weight (%) and the ounces you’d need to consume to get about 6 g of prebiotics (Van Loo et al. 1995).

Raw chicory root (64.6%, about 0.33 ounce). Used as a coffee replacement, this root provides the most prebiotic of any food.

Jerusalem artichoke (31.5%, about 0.6 ounce). Also called “sunchokes,” these tuber-like veggies have a potato-like texture and look like ginger roots.

Raw dandelion greens (24.3%,1 ounce). Available from organic markets, these greens have a bitter taste and can be tossed into a salad.

Raw leeks (11.7%; 1.8 ounces). Similar to onions, leeks are a great addition to salads.

Raw onions (8.6%; 2.5 ounces). Inulin content may vary with the variety of onion.

Probiotic Foods

Cultured or fermented foods have a wide variety of friendly microbes.

Yogurt. Only yogurts stamped with the “Live & Active Cultures” seal are guaranteed to contain beneficial bacteria like Lactobacillus and Bifidobacteria.

Sauerkraut. Fermented cabbage is a great source of probiotics. Look for the unpasteurized type, as pasteurization kills some friendly bacteria.

Miso. This fermented soy bean paste, popular in Japanese soups, is thought to contain over 160 bacterial strains that boost probiotic diversity in the gut.

Kombucha tea. This highly acidic fermented tea has a vinegar taste and smell with a slight fizz.


Million, M., et al. 2013. Gut bacterial microbiota and obesity. Clinical Microbiology and Infection, 19 (4), 305-13.

Slavin, J. 2013. Fiber and prebiotics: Mechanisms and health benefits. Nutrients, 5 (4), 1417-35.

Sommer, F., & B├ñckhed, F. 2013. The gut microbiota— masters of host development and physiology. Nature Reviews Microbiology, 11 (4), 227-38.

Tillisch, K., et al. 2013. Consumption of fermented milk product with probiotic modulates brain activity. Gastroenterology, 144 (7), 1394-1401.

Van Loo, J., et al. 1995. On the presence of inulin and oligofructose as natural ingredients in the Western diet. Critical Reviews in Food Science and Nutrition, 35 (6), 525-52.

West, N.P., et al. 2009. Probiotics, immunity and exercise: A review. Exercise Immunology Review, 15, 107-26.

IDEA Authors

Leave a Comment

When you buy something using the retail links in our content, we may earn a small commission. IDEA Health and Fitness Association does not accept money for editorial reviews. Read more about our Terms & Conditions and our Privacy Policy.