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A secondary analysis of a randomized clinical trial found that a probiotic supplement had only a minor and transient effect on the gut microbiome composition of children during and after antibiotic treatment, researchers reported late last week in JAMA Network Open.
The trial, which involved 350 children and was conducted at three hospitals in the Netherlands and two in Poland, found that a multispecies probiotic given to participants within 24 hours of initiating antibiotics had no effect on antibiotic-associated diarrhea (AAD), but did reduce the overall risk of diarrhea during and for 7 days after antibiotic treatment compared with placebo. For the secondary analysis, to better understand the underlying protective mechanism of probiotics, the investigators collected stool samples from 88 children in the trial (44 from the probiotics group and 44 from the placebo group) at four predefined times and conducted microbiota analysis.
Minimal effect on bacterial diversity
The stool samples were collected and analyzed at inclusion in the trial, on the last day of antibiotic use, on the last day of the study intervention, and 1 month after the intervention. Alpha diversity did not significantly differ between the probiotic and placebo groups during the first three collection times, and Beta diversity was not significantly different at any of the collection times. Shannon diversity (mean, 3.56 vs 3.09) and inverse Simpson diversity (mean, 3.75 vs –1.31) indices were higher in the placebo group compares with the probiotic group 1 month after intervention.
While the analysis did find that three of five bacterial genera contained in the probiotic—Ligilactobacillus, Lactiplantibacillus, and Lactobacillus—were more abundant in children from the probiotic group than the placebo group during supplementation, the difference between the groups disappeared after 1 month.
"It therefore remains debated whether probiotics have beneficial effects on antibiotic-induced microbiota composition aberrations," the study authors wrote. They add that future studies are needed to assess whether the observed transient effects on taxonomic composition and on diversity play any role in preventing AAD and other adverse effects from antibiotics.