Probiotics are healthy bacteria that we introduce into our microbiome, or digestive system, to boost the healthy bacteria that already lives there. Studies show that probiotics can benefit certain cancer patients, such as those experiencing gastrointestinal problems. However, each patient is different—therefore, probiotics are not recommended for everyone.

Probiotics can be found naturally in foods like Greek yogurt, cheese, kimchi, and pickles; they also exist in supplement and powder form. Taking probiotics can boost some of the healthy bacteria already in your gut, which works at its best when it has a balance of “good” and “bad” bacteria. A balanced gut is an important part of your body’s overall wellness.

Evidence shows that probiotics can help with long-term symptom management for cancer patients following treatment, including chemotherapy-related diarrhea. A 2014 study investigating the effects of administering probiotics to colorectal cancer survivors for 12 weeks saw a significant decrease in symptoms for patients suffering from irritable bowel symptom, ultimately improving quality of life for those patients.

Another randomized trial, conducted with 150 patients, found that patients who underwent chemotherapy and received probiotics experienced significantly less grade three and four diarrhea and also required fewer hospitalizations and dose reductions due to bowel toxicity. However, this group also had a higher number of neutropenic complications—meaning a lower-than-normal number of neutrophils, a type of white blood cell, in the blood. This can result in an infection.

In addition to alleviating  symptoms of diarrhea, probiotics can be beneficial for some patients who have pre-existing health problems such as irritable bowel syndrome and those experiencing other gastrointestinal issues like constipation, gas, or bloating, according to Stacy Kennedy, MPH, RD, a senior clinical nutritionist in Nutrition Services at Dana-Farber/Brigham and Women’s Cancer Center. Kennedy also recommends that these patients regularly change the types of probiotics they consume to get the benefit of a variety of probiotic strains.

Probiotics are not the only way to maintain a healthy gut or to improve gastrointestinal problems, Kennedy says. Fiber from fruits and vegetables, nuts, and whole grain foods can maintain and improve overall gut health. Gastrointestinal issues that patients may experience, such as gas, can also be chalked up to beverages such as soda, so switching your source of hydration can be helpful.

“Probiotics can definitely be helpful and they can serve a purpose in some cases,” Kennedy says. “It’s also important to look at individual cases to look at small changes that you can make, which can have big effects.”

There are also some patients who Kennedy would not recommend probiotics to, including patients who are on clinical trials with dietary restrictions, and patients who are neutropenic. It is important to speak with a doctor or nutritionist before adding probiotics to your diet during or after cancer treatment.

This article was originally published on February 16, 2018, by Dana-Farber Cancer Institute. It is republished with permission.