Most adults have probably heard of probiotics, even if all their knowledge is from Activia commercials. Probiotics replenish stores of beneficial bacteria depleted by antibiotics or missing from lack of eating a balanced diet -- a critical element of digestive health.

Yogurt may be the best-known source of probiotics, but fermented foods including sauerkraut, certain pickles and cheeses, buttermilk, soy sauce, miso, and wine are excellent sources of these gut-health-enhancing bacteria too.

Probiotics vs. Prebiotics

Don’t confuse probiotics with prebiotics. While probiotics help keep us healthy, prebiotics help keep those friendly bacteria in the probiotics healthy. Prebiotics are compounds such as polyols and inulin that you ingest, but don’t digest. Instead, the good bacteria gobble them up. 

When you consume prebiotic-rich foods like artichokes, bananas, beans, garlic and oats, you aren’t just feeding your body -- you’re also feeding your body’s beneficial bacteria. Prebiotics are the yen to probiotics’ yang; both are essential for optimal digestive health.

Probiotics and Health

Thanks to Jamie Lee Curtis and those Activia commercials, most folks know that probiotics combat bloating, diarrhea, constipation, and overall abdominal malaise. Probiotics also help crowd out harmful bacteria, because there's limited surface area for bacteria in your intestines. If you load your body with good bacteria, there’s less space for harmful bacteria to stake claim.

Optimizing digestion is just one benefit of probiotics. Studies indicate that probiotics may reduce ailments like high blood pressurelung diseasetooth decay. They may even give your memory a boost. They also regulate vaginal bacterial, combating yeast infections and bacterial vaginosis -- ailments that especially plague pregnant women. Speaking of pregnancy, studies show that pregnant women who consume probiotics give birth to babies with lowered incidence of allergies.

Probiotics and Performance

Can probiotics improve your athletic prowess? The answer may be yes. One Iranian study tracked how eating probiotic-rich yogurt affected competitive female swimmers after a 400-meter freestyle swim. Researchers concluded that swimmers who consumed probiotics suffered fewer respiratory infections and less shortness of breath. As a result, their VO2max improved. 

A systematic review published by the American College of Sports Medicine concluded that probiotics also accelerate fatigued athletes’ immune systems, helping them recover more quickly.

Probiotics and Body Composition

Want to lose belly fat? Grab a fermented treat and dig in. So suggests a study published in the British Journal of Nutrition. Researchers studied 210 people who consumed varying degrees of a specific probiotic strain. Subjects who consumed the most probiotics lost the most fat: 3 percent of belly fat in 12 weeks (compared to 1 percent for people who consumed fewer probiotics).

There’s no need to sweat too much about exactly how probiotics are beneficial; just know that they're good for you, and that you should consume them through your food or supplements. If you choose supplements, make sure to research the brand so you know you’re getting a quality product.