A Probiotic Mixture Decreases Neuropathy and Oxidative Stress Markers in Diabetic Rats

Diabetic neuropathy (DN) is a type of nerve damage caused by long-term hyperglycemia in diabetes mellitus (DM). The gut microbiota alters in DM. Therefore, improvement of the gut flora may affect neuropathic pain and oxidative biomarkers' responsiveness to the probiotic treatment. The present study aimed to assess the effects of probiotic supplementation on neuropathic pain and oxidative stress biomarkers in diabetic rats’ serum. Forty-eight rats (200-250 g) were randomly divided into four groups (n = 12 per group) to examine the effects of the probiotics mixture as follows: the control group (CO), and the diabetic groups received 1 ml probiotics mixture (DP) containing <em>Lactobacillus rhamnosus</em>, <em>Lactobacillus acidophilus</em>, <em>Lactobacillus delbrueckii</em>, <em>Lactobacillus plantarum</em>, and <em>Bifidobacterium bifidum</em> (10<sup>9</sup> CFU of each), 100 mg/kg Gabapentin (DG), or normal saline (DM) daily. The study used animals with plasma glucose concentrations between 70 and 100 mg/dl. Behavioral tests, including mechanical allodynia, cold allodynia, and thermal hyperalgesia, were used to evaluate the pain on days 1, 4, 7, 14, and 21 of the study. After that, the serum's biochemical analysis was completed. Taking the probiotics mixture decreased mechanical and cold allodynia as well as thermal hyperalgesia. The probiotics group also showed significant reductions in lipid peroxidation levels and increases in total antioxidant capacity (TAC) and glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities compared to the DM group. Our results showed that supplementation with the probiotics mixture could reduce pain-related behaviors in diabetic rats by enhancing the antioxidant capacity in their serum.