Disrupted gut microbiota promotes the progression of chronic kidney disease in 5/6 nephrectomy mice by Bacillus pumilus gavage.

BACKGROUND

Our previous study identified differences in the gut microbiota between patients with chronic kidney disease (CKD) and healthy individuals. We observed that antibiotic-treated mice exhibited symptoms similar to those of patients with CKD after receiving a gut microbiota transplant from patients with CKD. Bacillus pumilus (B. pumilus), an alien microorganism to both human and mouse gut microbiota, possesses antibiotic properties that can alter the microbial community structure. Therefore, this study aimed to explore how changes in the gut microbiota structure induced by the oral gavage of B. pumilus affect the progression of CKD. We sought to identify the gut microbes and metabolic pathways associated with CKD to lay the groundwork for future clinical probiotic applications in patients with CKD.

METHODS

We constructed sham-operated and 5/6 nephrectomy mice as the sham control (SC) and CKD models, respectively. CKD models were divided into a control group (CG) and an intervention group (IG). After 16 weeks of normal feeding, the IG were treated with B. pumilus by oral gavage, while SC and CG were treated with PBS once daily, 5 days per week, for 7 weeks. Fecal samples were collected for 16s rRNA sequencing and metabolomic analysis, kidneys were harvested for histological examination, and the colon was used for RT-PCR analysis.

RESULTS

B. pumilus intervention exacerbated gut microbial homeostasis in CKD mice and increased serum creatinine and urea nitrogen levels, further aggravating kidney damage. 16s rRNA and metabolomic analysis revealed that Parvibacter and Enterorhabdus were probiotics related to kidney function, while Odoribacter was associated with kidney injury. Metabolomic analysis showed that glycerophospholipid and lysine metabolism were upregulated in CKD model mice, correlating with kidney damage.

CONCLUSION

This study shows that changes in the gut microbiota can affect the kidneys through gut metabolism, confirming that the lack of probiotics and the proliferation of harmful bacteria leading to gut microbiota dysbiosis are drivers of CKD progression. Our findings provide a basis for clinical interventions using gut microbes and offer a reference for targeted probiotic therapy.