Many folks with HIV—including those on antiretroviral (ARV) treatment—frequently experience disorders in their gastrointestinal tract, a prime location for viral replication. Consequently, scientists continue to study how probiotics can help regulate the bacterial imbalances in the gut that can cause such health problems.

Previous findings have shown that high-quality probiotic supplements can help to relieve the diarrhea and nausea that affect some people with HIV. In addition, some of these products were shown to support bacterial balance and reduce inflammation in the gut, a side effect of the virus and ARVs.

But these good microorganisms aren’t all equally effective, explain researchers. Their benefits seem to depend on the strain of bacteria involved as well as how each person responds to the microbes. For instance, results from a recent study show that while some people’s guts welcome the miocroorganisms, others expel them.

“Probiotics should not be universally given as a ‘one-size-fits-all’ supplement,” cautions one expert. “Instead, they could be tailored to the needs of each individual.”

Researcher Stuart D. Federman, PharmD, the medical science liaison at Bristol-Meyers Squibb, says it’s key for people with HIV to track their nutritional intake and to keep their digestive tract healthy. “The best way to do this is to increase the natural gut flora through probiotics,” he suggests.

But more investigations are needed to provide a clear understanding of how probiotics work to alleviate intestinal inflammation, normalize mucosal function in the gut and regulate allergic reactions for those living with the virus.