1120-OR: The Pain-Relieving Effect of Bifidobacterium longum -pNZ44-Oxyntomodulin Engineered Probiotics on Painful Diabetic Neuropathy

Introduction and Objective: Painful diabetic neuropathy (PDN) is a prevalent diabetic complication associated with gut microbiota dysbiosis, though the exact mechanisms remain unclear. Oxyntomodulin (OXM), a gut hormone and dual agonist of GCGR/GLP-1R, has therapeutic potential but is limited by a short plasma half-life, requiring continuous intravenous infusion for efficacy. This study aimed to develop a novel oral delivery system for OXM and its analog using engineered Bifidobacterium as a carrier for PDN treatment. Methods: An OXM gene expression vector pNZ44-OXM for the Bifidobacterium longum probiotics was constructed (denoted as Bl-OXM). Human OXM sequence was fused with the signal peptide from Bifidobacterium longum ATCC15707 under the control of the p44 promoter. The recombinant plasmid pNZ44-OXM was introduced into ATCC15707 by electroporation, and transformants were selected using MRS plates containing 12.5 μg/mL chloramphenicol. Streptozotocin induced PDN mice were treated with Bl-OXM to investigate the effects on painful diabetic neuropathy in mice by oral administration. Gut microbiota analysis was used to detect changes in the intestinal flora of mice following probiotic treatment. Results: We demonstrated that administration of Bl-OXM effectively alleviated pain, reversed nerve fiber lesions, and restored neuronal hyperexcitability. Gut microbiota analysis revealed that Bl-OXM restored gut homeostasis disrupted in PDN mice, as indicated by the increased abundance of Lactobacillus and Bifidobacteriales genera in response to Bl-OXM treatment. Furthermore, probiotics treatment inhibited the activation of the TLR4/MyD88/NF-κB signaling pathway and reduced proinflammatory cytokines in the sciatic nerve of the PDN mice. Conclusion: Collectively, the intestinal microbiota regulation and pain-relieving effect of the engineered strain Bl-OXM presents a promising approach for PDN management.