The impact of long-term levofloxacin on the bacterial gut microbiome of young South African children

Abstract Disruptions to gut microbial communities in early life can have lasting effects on metabolism, immune function, and resistance to infections. Antibiotics, including levofloxacin, can alter gut microbiota composition, potentially leading to long-term dysbiosis. The long-term impact of levofloxacin on the gut microbiota, especially in young children, remains poorly understood. This study investigated the effects of prolonged levofloxacin therapy over 6 months on gut microbiota in children and the stability of these changes after treatment cessation. This work used samples that were collected as part of a cluster-randomized, double-blind, placebo-controlled trial that investigated the efficacy and safety of levofloxacin for multidrug-resistant (MDR) tuberculosis (TB) preventive treatment in healthy children under the age of five years exposed to MDR-TB in the home. Levofloxacin or placebo were administered daily for 24 weeks following randomization, and stool samples were taken at baseline, and at 24- and 48-week follow-up visits. Bacterial 16S rRNA sequencing was performed on the Illumina MiSeq platform and the changes in bacterial gut microbiota composition and diversity were assessed at different time points and compared between the levofloxacin and placebo arms for different age group. Changes in the functional potential of the gut microbiome were predicted based on the observed taxonomy. Gut microbiota analysis was stratified into three age groups: 0 to