Probiotics Do Not Reduce Superbug Colonization in Gut

Probiotics don’t stop superbugs from colonizing in very ill patients’ intestinal tracts, according to a recent study published in the journal Infection Control and Hospital Epidemiology.

Researchers from the Washington University School of Medicine in St. Louis observed 70 patients admitted to the ICU at Barnes-Jewish Hospital in St. Louis in order to determine if the probiotic Lactobacillus rhamnosus GG was able to prevent the intestinal colonization of superbugs.

The probiotics are live microorganisms believed to maintain balance in the gut and boost resistance to harmful germs. The superbugs the researchers monitored for were Clostridium difficile (C. diff), vancomycin-resistant Enterococcus (VRE) and Pseudomonas aeruginosa.

Patients received either probiotics and routine care or only routine care for the duration of the observation period. Probiotics were administered to the patients twice daily for up to two weeks. The researchers then evaluated whether the superbugs were able to colonize the patients’ intestinal tracts. The investigators noted that the colonization is the first step for patients who develop full-fledged infections.

The drug resistant superbugs were able to colonize in 10% of the patients in the routine care plus probiotic group. That number grew to 15% of patients in the routine care only group. However, the researchers said this difference was not statistically significant.

“Probiotic use is an intriguing topic,” explained lead author Jennie H. Kwon, DO, clinical researcher in the Division of Infectious Diseases, in a press release. “With fewer therapies available to treat multidrug resistant organisms, innovative methods to prevent or eliminate gastrointestinal colonization are necessary.”

There were limitations in conducting this study, the researchers noted. For example, there was a small sample size, a short period of patient follow up, and use of a single dose of probiotic. The researchers also said that the study was confined to only gastrointestinal bacteria — the study did not examine the impact of probiotics, if any, on preventing the superbug colonization in the stomach or upper respiratory system.

“Although our findings suggest that probiotics do not help prevent gastrointestinal colonization with drug resistant organisms in critically ill patients, further study is necessary in this field,” Kwon concluded. In the future, the researchers hope to examine the effects of probiotics on hospitalized patients, though not those admitted to the ICU.