Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In




What you need to know now for optimum health.

Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.

There are many pros of probiotics—those microscopic bugs that populate our guts play a big role in overall health. Probiotics boost your immune and digestive systems, and protect your gut’s lining. These beneficial bacteria may also help treat diarrhea, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), ulcers, lactose intolerance, and recolonize the gut’s “good” bacteria after a course of antibiotics.

Stress, medications, poor diet, and even age give the “bad” bacteria a chance to gain a foothold in the gut—and thereby compromise immunity, digestion, and more. “Now more than ever, we are giving the bad guys a chance to get active with stress and the over-usage of antibiotics,” says Shekhar K. Challa, board-certified gastroenterologist and author of Probiotics for Dummies. “There’s also evidence that as we age, we lose more and more of the good guys.” Taking a probiotic supplement is a good defense. “We have around 100 trillion bacteria in our colon, and as long as the ‘good guys’ are 90 trillion or above, the ‘bad guys’ behave,” says Challa.

New Findings

Promising research is looking into how probiotics may prevent and treat obesity, mental health issues, autism, asthma, certain types of cancer, and even heart, liver, and kidney disease. “I strongly believe that the benefits of probiotics go beyond digestive and immune health,” says Challa. Intriguing recent research suggests a link between gut flora composition and body weight. “The microbial populations in the gut of obese and lean people are different,” explains Challa. “When obese people lose weight, their gut flora changes to become like that of lean people, clearly suggesting that obesity may have a microbial element.”

A healthy balance of gut flora could also benefit the mind. A recent UCLA study, published in Gastroenterology, shows that changing probiotic bacteria balance through diet affects brain function. “One of the most interesting findings I’ve seen lately links gut bacteria and mental health,” says Jeff Cox, author of The Essential Book of Fermentation: Great Taste and Good Health with Probiotic Foods.

What’s Best for You?

Most probiotic supplements contain two or more strains that work synergistically. Probiotic supplements can contain 15,25, 30, 50, 100, 200, 400 billion—or more—live cultures. Some common probiotic strains:

1. L. acidophilus: A Lactobacillus species that lives in the intestine and aids in digestive health.

2. L. rhamnosus and L. fermentum: These Lactobacillus species, along with L. acidophilus, have successfully treated and prevented vaginal yeast infections. 

3. L. casei: In a recently published double-blind study, 46 patients with rheumatoid arthritis (RA) took L. casei supplements daily for eight weeks. Researchers concluded that the L.casei supplement improved inflammatory status in RA patients, calling for further studies.

4. L. plantarum: Two studies of elderly participants, published in Nutricion Hospitalaria, showed that this Lactobacillus strain enhanced their immunity and improved overall health.

5. L. reuteri and Streptococcus thermophilus: Research shows that these probiotic strains (along with others) can be effective in preventing or treating gastroenteritis—also known as the stomach flu.

6. B. animalis: This strain of Bifidobacteria helps regulate bowel movements, plus reduce intestinal inflammation and harmful bacteria. In addition, the gut microbiota of obese research participants was depleted in B. animalis, researchers reported in the International Journal of Obesity.

7. B. breve:  This Bifidobacteria strain, which lives in the gut and vagina, can ward off E. coli and yeast infections. It helps your body absorb nutrients and digest fiber.

8. B. lactis and B. longum: These good bacteria strains improve digestion and boost gut health and immunity. They also can help address inflammation, allergies, and high cholesterol. B. longum shows promise as a cancer fighter.

What Exactly are Prebiotics?

Did you eat a banana today? This common food contains prebiotics—special fibers that stimulate your gut’s good bacteria to grow and become active. Prebiotics and probiotics work together for your digestive health.

Prebiotics can be found in many foods including artichokes, flaxseeds, garlic, onions, soybeans, and wheat. Yacon root, a prebiotic food, has been used for centuries in Peru to make a natural, low-glycemic sweetener, says David Wolfe, author of Superfoods: the Food and Medicine of the Future.

A Shopper’s Guide

You’ll find probiotic supplements specially formulated for infants and toddlers, children, men, women, seniors, and even pets. Some supplements are specifically formulated for immune support, digestive balance, bowel regularity, or other health challenges, and blended with enzymes, vitamins, or prebiotics. Also look for raw, heat-resistant, vegetarian, vegan, gluten-free, dairy-free, and allergen-free formulas.

There are a variety of convenient forms available. Choose the one that’s best for your lifestyle and health needs:

Liquids: Look in your store’s refrigerator case for probiotic drinks and shots. These liquid formulas can be particularly helpful for folks who have trouble swallowing pills.

Capsules: Many probiotic capsules are designed to resist breakdown by stomach acids so they reach the intestines intact.

Pearls: Small pearl capsules are particularly easy to swallow and convenient to carry in your purse or when traveling.

Tablets: Many tablet supplements are time-released, so you only need one daily dose.

Chewable tablets: Yummy natural flavors make it easy for kids (and adults) to take their daily probiotic supplement.

Sprays: Sprays may combine homeopathic remedies and probiotic strains to provide intestinal discomfort relief.

Mints: What could be simpler than popping a mint in your mouth? They also support tooth and gum health, and help whiten teeth and freshen breath.

Probiotic soaps: Help to balance skin bacteria topically, and are suitable for oily and dry skin.

In addition to supplements, other probiotic sources include yogurt, kefir, miso, and other fermented foods, says Cox. Look for “live and active cultures” on food labels.

Our Product Picks

GARDEN OF LIFE RAW Probiotics—available in women’s, men’s, and kids’ formulas—combine a comprehensive blend of whole-food derived, uncooked, and unadulterated bacterial strains
guaranteed to “arrive alive.”

JARROW FORMULAS Jarro-Dophilus EPS 25 Billion, with eight beneficial probiotic strains, is shelf-stable at room temperature and enteric coated to ensure safe delivery to the intestinal tract.

NATURE’S WAY Primadophilus Reuteri features the unique Lactobacillus strain (reuteri) found in human breast milk, one of the first defenses a nursing mother passes to her child. Safe for infants and toddlers.

RENEW LIFE Ultimate Flora Critical Care 50 Billion is specially formulated to relieve occasional constipation, gas and bloating—and each capsule includes 50 billion live cultures.

THE VITAMIN SHOPPE Ultimate “10” Probiotic blends 10 different beneficial bacterial species to support a healthy balance of intestinal microflora—along with the prebiotic FOS.