A gut-health expert explains the probiotics that are worth taking — and how to increase your intake of 'good' bacteria through food

A gut-health expert explains the probiotics that are worth taking — and how to increase your intake of 'good' bacteria through food
A gut health expert said most adults can get the probiotics they need through fermented foods like yogurt.Insider Inc.
  • A gut-health expert said certain probiotic species could help treat disorders like IBS and eczema.
  • Alexandra Shustina said most adults should eat a probiotic- and fiber-rich diet for good gut health.

Navigating the vast number of probiotic supplements on the market can be tricky.

Probiotics are bacteria that live inside our bodies and are also found in fermented foods like yogurt, cottage cheese, buttermilk, and pickles preserved in saltwater.

There are thousands of strains of probiotics. Each one plays a role in maintaining equilibrium in our bodies, from gut and vaginal health to mental health. Many of these strains are available for purchase in supplement form, but the majority lack research on whether they improve gut health, Insider previously reported.

Despite the lack of research, the $60 billion probiotic-supplement industry is expected to grow 9% every year until at least 2028.

Dr. Alexandra Shustina, a board-certified gastroenterologist and internist, as well as the founder of Whole Gut Health, told Insider researchers still had a lot to learn about how probiotic strains affect the body. Above all, eating a balanced diet with fermented foods offers the most benefits for your gut, Shustina said.


"I don't believe supplements are necessary for healthy people if they are getting what they need from their diet, which is absolutely possible, but they need to be educated on what to eat," Shustina said.

That said, for those who could benefit from a boost — such as people with irritable bowel syndrome — here are Shustina's tips on how to make decisions when shopping for probiotic supplements:

Certain strains of probiotics can treat digestive issues and other disorders

In her practice, Shustina said she commonly saw patients with irritable bowel syndrome. IBS is a disorder that affects 10 to 15% of adults and causes diarrhea, constipation, gas, bloating, and abdominal pain.

Shustina said some of the probiotic strains used to treat IBS were lactobacillus rhamnosus GG, lactobacillus plantarum, and bifidobacterium bifidum.

Certain probiotic strains can help people who are taking antibiotics to treat an infection. That's because as they try to kill the bad bugs causing the sickness, antibiotics can inadvertently kill off the "good bugs" that live in our body, too. Reintroducing the saccharomyces boulardii organism can mitigate those side effects.


Probiotics can also alleviate the symptoms of eczema, a common skin condition that causes red, itchy flare-ups. Shustina said lactobacillus species of probiotics, particularly lactobacillus rhamnosus GG, could help people with eczema.

Fermented foods provide the body with diverse and plentiful probiotic strains

For most adults, Shustina said the best way to keep your gut healthy was through a probiotic- and fiber-rich diet.

Fiber is sometimes called a "prebiotic" because humans cannot digest it, but bacteria can. Bacteria can use the fiber as fuel to live longer inside of the gut, helping the body with immunity and digestion.

Sourdough bread, sauerkraut, kimchi, and yogurt are foods that contain enough probiotic strains for a healthy gut. The doctor also said people who don't like those foods could easily ferment their own veggies in saltwater.

Sleep, exercise, and stress maintenance also help maintain a healthy microbiome, Shustina said.


The strains to look out for when shopping for probiotic supplements

If your diet is low in probiotic-rich foods, and you're struggling to up your intake, Shustina said to look for supplements containing many types of lactobacillus strains, including lactobacillus acidophilus and bifidobacterium strains.

"You want to have a robust microbiome and diverse microbiome," she said. "You don't want to have certain groups more than there are supposed to be."

Since the supplement industry is largely unregulated, illegitimate sellers may offer pills that do not contain what's listed on the bottle, Shustina said. She recommends asking a doctor, health coach, or holistic-medicine practitioner about professional-brand probiotic supplements or ones with good data to back up what's in the product.

"Natural products in some ways are similar to pharmaceutical products — you have to know what you're doing," she said. "If you are not sure, food as medicine is always safer. So using food as medicine, especially if you're healthy, is usually to be the first line."