Probiotic safely reduces S. aureus colonization in human trial
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A probiotic safely reduced Staphylococcus aureus colonization in a phase 2 human trial without harming other gut microbiota, suggesting a potential approach to preventing infection without using antibiotics.
Study participants who received the probiotic Bacillus subtilis were found to have significantly lower levels of S. aureus colonization than those given a placebo, according to a study published in The Lancet Microbe.
“The probiotic we use does not ‘kill’ S. aureus, but it specifically and strongly diminishes its capacity to colonize,” Michael Otto, PhD, a senior investigator at the National Institute of Allergy and Infectious Diseases, said in a press release. “We think we can target the ‘bad’ S. aureus while leaving the composition of the microbiota intact.”
A 2015 analysis of twins and whether genetics affect the risk for S. aureus colonization suggested that probiotics could be used to prevent or reduce S. aureus, as well as prevent MRSA infections.
“S. aureus decolonization strategies have generally used antibiotics, which are inherently problematic because of the dangers associated with the destruction of the natural microbiota and the spread of antimicrobial resistance,” Otto and colleagues noted in the new study.
Previously, Otto’s research group found that B. subtilis can prevent a sensing system in S. aureus from functioning, which prevents its ability to colonize. To test this, Otto and colleagues conducted a single-center, double-blind trial of the probiotic, recruiting 115 people in the Songkhla region of Thailand between Jan. 29, 2021, and June 30, 2021, who had been colonized by S. aureus either in the intestine (84), nose (50) or both (19).
In all participants, researchers determined the composition of their intestinal microbiome before and after treatment.
Participants in the trial group were given doses for 7 days of treatment, returning weekly for 3 weeks to receive a week’s worth of doses until the fourth visit, when they received eight doses. After completing this 30-day treatment, the researchers took nasal swab and fecal samples the next day.
The researchers found those given the probiotic B. subtilis had a 96.8% reduction of S. aureus in stool and a 65.4% reduction in the nose.
Overall, the researchers reported that the probiotic eliminated more than 95% of S. aureus in participants without altering their gut microbiota.
“Intestinal S. aureus colonization has been evident for decades but mostly neglected by researchers because it was not a viable target for antibiotics,” Otto said in the press release.
“Our results suggest a way to safely and effectively reduce the total number of colonizing S. aureus, and also call for a categorical rethinking of what we learned in textbooks about S. aureus colonization of the human body.”
References:
- Probiotic blocks staph bacteria from colonizing people. https://www.nih.gov/news-events/nih-research-matters/probiotic-blocks-staph-bacteria-colonizing-people. Published Feb. 7, 2023. Accessed Feb. 8, 2023.
- Piewngam P, et al. Lancet Microbe.2023;doi:10.1016/S2666-5247(22)00322-6.