Temporal effects of lascufloxacin on human gut and salivary microbiota: Analysis using next-generation sequencing method.

Introduction: Antimicrobial treatment disrupts human microbiota. The effects of lascufloxacin (LSFX), a new fluoroquinolone, on human microbiota remains unknown. Therefore, in this study, we aimed to evaluate the effects of LSFX administration on the gut and salivary microbiota of healthy participants and those with pneumonia.

Methods: LSFX (75 mg, once a day, orally) was administered to healthy adults (healthy group) and adult patients with pneumonia (pneumonia group), and fecal and saliva samples were collected at five time points (Days 0, 3, 7, 14, and 28). Using the collected samples, α- and β-diversity indices, as well as bacterial composition of the gut microbiota and salivary microbiota were analyzed using next-generation sequencing.

Results: In the healthy group, α-diversity indices of the gut and salivary microbiota were reduced and the lowest values on Day 3. For the gut microbiota, the Chao1 index (richness) recovered on Day 28, whereas the Shannon index (evenness) did not. In the salivary microbiota, the Chao1 and Shannon indices did not recover within the 28 day period. The β-diversity indices changed after LSFX administration and subsequently recovered on Day 28. After LSFX administration, the abundance of the Lachnospiraceae family decreased in the gut microbiota, and the abundance of Granulicatella, Streptococcus, Prevotella, Absconditabacteriales(SR1), and Saccharimonadales decreased in the salivary microbiota. In the pneumonia group, the α-diversity indices were lowest on Day 14 after LSFX administration.

Conclusions: We elucidated that LSFX administration differentially affected the gut and salivary microbiota; however, the richness and beta diversity recovered within 28 days.