What Are Probiotics & What Do They Do? (2024)

What are probiotics?

Probiotics are live microorganisms (microbes) that can have beneficial effects on or inside your body. Every human body is home to trillions of microorganisms that live with us and help support our bodily functions and health. Not all of the microbes we may carry are helpful to us — some types (germs) can be harmful. But beneficial microbes, like probiotics, help to control the potentially harmful types.

Probiotic products contain select, beneficial types of microbes to add to the populations already living in your body. Many probiotics are oral supplements designed to be ingested into your gastrointestinal tract. Others are topical products that you can apply to your skin or to the mucous membranes inside your body cavities, like your nose or genitals. These are all places where beneficial microbes commonly live.

What do probiotics do?

Probiotics are food and health products that contribute live, beneficial microbes to the populations within your gut and elsewhere, in order to strengthen those communities. They’re meant to prevent and treat dysbiosis — an imbalance or a deficit of beneficial microbes in your microbiome. When they work, the microbes take up residence on or in your body, adding to the populations already living there.

Not all probiotics are alike, though. Different types of microbes function differently within your body, so different types might be better or worse for your condition. Probiotics also aren’t regulated by the FDA, so manufacturers don’t have to prove the quality or even the contents of their products. It’s a good idea to consult a knowledgeable healthcare provider about which probiotics might work best for your needs.

When are probiotics recommended?

If you have symptoms of dysbiosis, in your digestive system or elsewhere, your healthcare provider might recommend probiotics to help bring your microbiome back to balance. If you’ve recently had an illness or treatment that weakened your microbiome, your provider might suggest probiotics to help rebuild it. For example, they might suggest taking or using probiotics after finishing a course of antibiotics.

Some people take a daily probiotic supplement to maintain their general wellness. You might want to do this if you’re prone to gut health issues and you notice it helps. A healthy gut microbiome can boost your overall immunity, reduce inflammation and help keep your bowels regular. Everyday things like stress and food choices can diminish your gut microbiome, and probiotics are one way to help restore it.

Which probiotics are effective?

For a probiotic to have any benefit to your health, it must:

• Be of a variety that has proven benefits for your body.
• Be in a form that’s safe to consume or apply to your body.
• Contain viable microbes that have survived the commercial process.
• Be able to survive the journey through your digestive tract (if it’s an oral probiotic).

Some of the most frequently studied and recommended probiotics include:

• The Lactobacillus genus, including L. acidophilus, L. rhamnosus, L. casei and L. plantarum.
• The Bifidobacterium genus, including Bifidobacterium longum and Bifidobacterium breve.

Acidophilus (L. acidophilus) may be the most well-known probiotic on the market today, possibly because it has so many different applications. Acidophilus is found naturally in your mouth, gut, stomach, lungs, vagin* and urinary tract, and it can help restore balance in all of these microbiomes.

These products are all available over the counter (OTC), in grocery stores, drug stores and health and wellness stores. They come as dietary supplements (capsules, liquids or powders) or as topical lotions or creams for different uses. Your healthcare provider can help you select a good one to try for your needs.

You can also get probiotics in less concentrated quantities from fermented foods and drinks, including:

• Yogurt and kefir.
• Cottage cheese.
• Miso soup.
• Kombucha.
• Sauerkraut or kimchi.
• Pickles and pickle juice.

Fermented foods and drinks are one way to get more probiotics into your GI tract. Food processing can sometimes destroy these natural probiotics, though, so check the labels for “live and active cultures”.