Oral Lactobacillus reuteri LR06 or Bifidobacterium BL5b supplement do not produce analgesic effects on neuropathic and inflammatory pain in rats.

Jiangju Huang,Jian Wang,Wangyuan Zou,Qulian Guo,Chuanlei Zhang

doi:10.1002/brb3.1260

Abstract

BackgroundPrevious studies have reported that certain bacteria exert visceral antinociceptive activity in visceral pain and may also help to relieve neuropathic and inflammatory pain. Objective: The aim of this study was to explore the analgesic effect of Lactobacillus reuteri LR06 (LR06) or Bifidobacterium BL5b (BL5b) in chronic pain in vivo.DesignRats were randomly assigned into four groups: sham, Chronic Constriction Injury (CCI)/Complete Freund's Adjuvant (CFA) + control, CCI/CFA + LR06, and CCI/CFA + BL5b. Rats from the probiotic groups were treated with 1 x 109 cfu (LR06 or BL5b) daily through gavage for 14 days after a pain model was successfully established. Mechanical and thermal hyperalgesia were used to assess the analgesic effect of the probiotics. Iba1 was used to verify the microglial inflammatory reaction in the different groups.ResultsThe results showed that probiotics L. reuteri LR06 or Bifidobacterium BL5b had no significant antinociception effects in chronic pain rats. The chronic pain‐induced activation of microglia (Iba1) was not relieved by probiotics in CCI/CFA‐induced neuropathic or inflammatory pain rats.ConclusionOur results suggested that L. reuteri LR06 or Bifidobacterium BL5b had no antinociceptive effects on CCI‐induced neuropathic pain and CFA‐induced inflammatory pain in rats.

Highlights

Chronic pain is defined as continuous, long‐term pain lasting more than 12 weeks
In this study, we hypothesized that oral supple‐ mentation with Lactobacillus reuteri LR06 or Bifidobacterium BL5b can relieve Constriction Injury (CCI)‐induced neuropathic pain and Complete Freund's Adjuvant (CFA)‐induced inflam‐ matory pain in rats
Our data showed that the L. reuteri LR06 and Bifidobacterium BL5b have no effective pain relief in CCI‐induced neuropathic pain or CFA‐induced inflammatory pain

Summary

| INTRODUCTION

Chronic pain is common worldwide, with an esti‐ mated rate ranging from 8% to 60% (Phillips, 2009), and profoundly impacts the overall quality of life and mental health without effec‐ tive management (Breivik, Collett, Ventafridda, Cohen, & Gallacher, 2006). The clinical therapeutic potential of probiotic bacteria, particu‐ larly Lactobacilli reuteri and Bifidobacteria, is the focus of consider‐ able interest in many fields, with chronic pain treatment being no exception (Quigley, 2005). Few studies have focused on the re‐ lationship between probiotics and neuropathic and inflammatory pain. In this study, we hypothesized that oral supple‐ mentation with Lactobacillus reuteri LR06 or Bifidobacterium BL5b can relieve CCI‐induced neuropathic pain and CFA‐induced inflam‐ matory pain in rats

| MATERIALS AND METHODS

Findings

| DISCUSSION