Your Complete Probiotics Guide
Lists of probiotics are touted on yogurt labels and bottles of probiotic supplements line vitamin aisles. Learn why this "good bacteria" is one of the biggest recent food trends—and discover if you should be adding more probiotic foods to your menu.
Wild but true: While most of us are vigilant about disinfecting the germiest items in our homes and squirt on hand sanitizer countless times a day, we're actually made of mostly bacteria ourselves.
"Your body actually has more bacterial cells than human cells," says Katie Goldberg, MCN, RDN, owner of Katie Goldberg Nutrition.
Probiotics are one of the most-discussed forms of this healthy bacteria that keeps our systems running at peak condition. We spoke with nutrition experts to get the real probiotic definition and to score the dirty truth about whether we need to worry about including more probiotic foods and probiotic supplements to our routine.
What are Probiotics, Exactly?
Probiotics are beneficial live bacteria in our digestive system, or "gut." There, they impact digestion, of course.
"A healthy gut has also been linked to the prevention of many health conditions such as skin conditions like eczema, autoimmune disorders, and even obesity and diabetes, so the benefits extend far beyond good digestion," says Sarah Gold Anzlover, MS, RDN, registered dietitian nutritionist and owner of Sarah Gold Nutrition.
Research has also linked probiotics to boosted immunity, mental health, and mood.
According to the Journal of Probiotics & Health, dozens more studies are in the works to see if probiotics can also impact:
- Reduce incidence of colds and the flu
- Treat kidney stones
- Prevent gum disease and teeth issues
- Combat antibiotic-resistant bacteria
- Fight cancer
Do I Need to Add Probiotics to My Diet?
"Most people can benefit from including probiotics in their diet and many of us don't get enough," Anzlover says. "Stress, our environment, our diet, and antibiotic use can all deplete the good bacteria in our gut and results in an even greater need for consuming probiotics. If you've recently taken antibiotics, you may benefit from a greater dose from supplements to restore the good bacteria."
Related: 11 Sneaky Habits Harming Your Health
Increased consumption of probiotic foods is often recommended for those recovering from food poisoning or other infections that require treatment via antibiotics. As the name suggests, these medications kill off good and bad bacteria, says Tanya Freirich, MS, RDN, registered dietitian nutritionist and owner of Tanya B Nutrition.
"Generally healthy people will also have little probiotic side effects from consuming these foods, most often a little bit of gas," Freirich says.
Just as important as consuming probiotics is eating prebiotics, "a non-digestible component found in vegetables, whole grains, and some fruits, which acts as food to foster the growth of more probiotics naturally," Anzlover adds.
What are the Best Probiotic Sources?
According to our nutrition pros and the Journal of Probiotics & Health, the best probiotic food include:
- Miso soup
- Natto (fermented soybeans)
If something has been fermented, it likely contains at least a small amount of probiotics. For the biggest health benefits, include a mix of these foods several times each week.
"Getting a variety of these foods as well as keeping processed sugars to a minimum is key to keeping your microflora flourishing," says Emily Henry, RDN, registered dietitian nutritionist for MealShare, a mindful eating app that connects consumers to dietitians.
Do I Need a Probiotic Supplement?
"People with compromised immune systems and pregnant women may want to avoid certain fermented foods for food safety reasons, and steer clear of probiotic supplements since supplements are not well regulated," Anzlover says.
In fact, while Americans spent $2 billion on probiotic supplements in 2017, research published in the Annals of Internal Medicine has found that safety of these supplements is far from guaranteed.
"Check with your doctor or a dietitian that specializes in your condition to see what is safe for you and to get his or her recommendation for the healthiest probiotic supplement options," Anzlover recommends.