Probiotic effects of Clostridium cellabutyricum against Pseudomonas aeruginosa infection in an antibiotic-induced gut microbial dysbiosis mouse model.

OBJECTIVE: Gut microbiota dysbiosis induced by antibiotic use weakens its colonization resistance against opportunistic pathogens, increasing the risk of invasion and infection. While probiotics have the potential to restore the impaired gut microbial structure and prevent respiratory tract infections, the effectiveness of specific strains and the underlying mechanisms remain largely unexplored. In this study, the preventive effects of a novel butyrate-producing bacterium, Clostridium cellabutyricum YQ-FP-027against Pseudomonas aeruginosa infection after antibiotic exposure were investigated in antibiotic-pretreated mice model. METHODS: Phenotypic characterizations including the bacterial load in the lung, the assessment of gene expression of immune factors in lung tissue using qPCR, and detection of gut microbial composition using 16S rRNA sequencing were conducted. Pulmonary bacterial load and expression levels of immune factors of lung tissue, and gut microbial composition were evaluated. RESULTS: Our results demonstrated that YQ-FP-027ameliorated lung tissue integrity, significantly reduced pulmonary bacterial burden, and decreased the expression of interleukin-1β and TNF-α, while enhancing the expression of interleukin-10 and cathelicidin-related antimicrobial peptide. Furthermore, YQ-FP-027increased the abundance of Lachnospiraceae in the gut and reduced the abundance of opportunistic pathogens such as Enterococcaceae and Helicobacteraceae. CONCLUSIONS: These results suggest YQ-FP-027exerts probiotic effects by restoring gut microbiota balance, enhancing intestinal barrier function, and positively influencing pulmonary immune responses through the gut-lung axis. This study reveals the preventive potential of YQ-FP-027against P. aeruginosa infection in the context of gut microbiota dysbiosis, offering a novel preventive strategy.