Can Probiotics Cause Gas? Functional MDs Explain The Side Effect

Most people buy probiotics to support their digestive needs.* So, what happens when you start taking them and notice yourself becoming a little more gassy? Well, you might be a little peeved, or at the very least confused.

We get it...it stinks. So, to help make sense of this potential, unexpected side effect, mbg dug into the research and chatted with functional medicine doctors. Here's what they have to say. (Curious about other potential side effects of probiotics? Check out our guide.)

Can probiotics cause gas?

The short answer is: sometimes. One study on probiotics states that flatulence and bloating are, in fact, two of the most common side effects1. Yet, "probiotics are generally considered safe and well tolerated," the authors note.*

Why do probiotics sometimes cause gas?

"Many people can get gas or bloating in the first week or two [of starting a probiotic]," functional medicine doctor and mbg Collective member Amy Shah, M.D., once told mbg. This happens because "it's a new bacteria for your ecosystem," she explains.

According to integrative medicine doctor Bindiya Gandhi, M.D., "Everyone's microbiome is always changing." If you're suddenly introducing a new bacteria to the environment—even if it's a good bacteria—the microbiome will have to adjust. "This usually happens when someone has a gut imbalance of good and bad bacteria," Gandhi adds.

Can you do anything to help?

If you're experiencing gas after starting a probiotic, try lowering your daily intake. Start by taking "one pill every three days and slowly come back to the recommended dose," integrative gastroenterologist Marvin Singh, M.D., once recommended.

Additionally, it may be helpful to eat foods rich in prebiotics, which can help the probiotic bacteria flourish. "Prebiotics are largely nondigestible fibers that provide nourishment for beneficial bacteria," Singh writes for mbg. "Think of prebiotics as fertilizer for the good guys."

If the side effects don't subside after a few weeks of taking probiotics, visit a doctor or gastroenterologist. "Definitely talk to your functional or integrative doctor because that is a telltale sign something else is going on underneath," Gandhi says. In the meantime, you may need to stop taking the probiotic you're currently on and find one with targeted strains that meet your specific digestive needs.*

Bottom line.

Probiotic supplements contain living bacteria, which are meant to help balance the gut microbiome.* However, the introduction of new bacteria might temporarily unsettle your gut microbiome, leading to side effects like gas. After a few weeks, however, probiotics have been shown to support various aspects of digestive health.* If the symptoms haven't gone away by then, check in with your doctor.