Though probiotics are generally safe, those who are critically ill or have a compromised immune system should avoid them. When the immune system is weakened, introducing new bacteria may trigger infections.
Providers disagree about whether those with SIBO should take probiotics. Morra advises these patients to avoid them: “If you have SIBO and take probiotics, you’re potentially just adding fuel to the fire.”
Still, Rountree and Ruscio take a different view, noting that a number of studies suggest probiotics are beneficial for treating SIBO. Ruscio says one study showed probiotics to be more effective than an antibiotic in combating digestive symptoms in people with the condition.
“Probiotics can actually be antibacterial,” he explains. “And probiotics don’t colonize, which is probably why they don’t increase bacteria in the small intestine.”
He suspects probiotics may compete with SIBO bacteria for food, helping starve them, and stimulating intestinal motility, which can help sweep the hostile bugs away.