Risks and How To Take Them Safely

Probiotics, helpful bacteria that can support gut health, are typically safe to take. Risks are generally more common in people with severe illnesses. Others may develop minor side effects, such as bloating or gas.

These bacteria are mostly found in foods like yogurt and kimchi. Probiotic supplements and products include drinks and shots, cereal, chips, and chocolates.

Probiotics are generally safe to consume in adults. Side effects are usually minor, such as symptoms like bloating or gas.

Is it possible to overdose on probiotics? “Generally not,” Matthew Ciorba, MD, professor of medicine in the gastroenterology division at the Washington University School of Medicine, told Health.

“One may experience [gastrointestinal] distress or bloating if taking too high of an amount, depending on the probiotic,” said Dr. Ciorba. This would not be considered an overdose.

Few studies have examined the safety of probiotics in detail, especially over a long period. It’s likely safe to include probiotic foods, like live-culture yogurt, in your diet. However, you should ask a healthcare provider before starting probiotic supplements.

Risk factors that increase the likelihood of complications from taking probiotics include:

• Severe illnesses, such as HIV
• Recent surgery
• Weak immune system, such as from chemotherapy

The use of probiotics has caused blood infections in some people who were severely ill or had a weak immune system. Probiotic use should be medically supervised for these groups.

Only strains with proven benefits for a person’s condition should be used. Remember that probiotic use is not a substitute for conventional therapy.

Probiotics are live bacteria that can have benefits when you consume them. Many of the probiotics found in products are similar to or the same as those naturally found in your digestive system.

Probiotics include Lactobacillus and Bifidobacterium. These bacteria benefit your body in various ways. Some probiotics help digest food or produce vitamins. Others kill off cells that cause disease.

Probiotics may also stop the growth of harmful gut bacteria and protect the gut barrier, or the walls of the gastrointestinal tract. It prevents compounds like toxins from being absorbed into the bloodstream.

One review found that probiotic supplements may have other benefits, such as:

• Improve stool consistency
• Promote regular bowel movements
• Strengthen the immune response
• Support female reproductive health and increase helpful vaginal bacteria

Probiotics are found in many forms but may not be in some of the foods you associate with them. Many people assume fermented foods or beverages—made through the controlled growth of bacteria—always contain probiotics. The bacteria must offer a benefit for the food to be considered a probiotic by the Food and Agriculture Organization.

Not all fermented foods include bacteria that have proven benefits. The bacteria may not remain alive in your gut after you digest it. Heat or pasteurization sometimes kills live bacteria.

Fermented foods that may contain live microbes include:

• Fermented vegetables, such as unpasteurized sauerkraut
• Traditional kimchi
• Yogurt or kefir that says “contains live cultures” on the label

The dose needed for probiotics depends on the bacteria strain and product. It’s not possible to state a general dose. It should be based on human studies showing a benefit. The type and dose should match the research for a particular disease.

Studies provide some guidance on probiotic species, strains, and doses that might alleviate symptoms of specific conditions. There are currently no government guidelines about the use of probiotics, including types or amounts.

There is also no standardization of products. You can find many supplements with various types and amounts of bacteria and products that contain probiotics. The quality of probiotic products depends on the manufacturer.

Although the risks are minimal for healthy adults, Dr. Ciorba noted that people who take probiotics for their digestive health should weigh whether they are seeing any benefit. It might not be worth the money if not. 

There are no definitive guidelines for the precise types and amounts of probiotics to take, including how much is too much. Ask a healthcare provider for guidance, particularly regarding a probiotic supplement. Listen to your body to identify potential side effects like gas.