Microbial Biotechnology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan.
Microbial Biotechnology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan.
Nutrition. 2023 Oct;114:112110. doi: 10.1016/j.nut.2023.112110. Epub 2023 Jun 5.
The aim of this study was to examine the effects of probiotic supplementation on extensor digitorum longus (EDL) regeneration after grafting in mice.
EDL muscles were ortho-transplanted in mice. The experimental group was given 1 × 10 colony-forming units/g body weight of Lactobacillus rhamnosus daily after EDL muscle transplantation surgeries. EDL muscle transplants were recovered after 3, 5, 7, and 14 d post-transplantation from the control as well as the experimental animals and processed for histologic analysis.
At day 3 post-transplantation, the inflammatory cells had infiltrated into the grafted EDL muscles and the central section of the grafted tissue contained necrotic fibers. At day 5 post-transplantation, the concentration of inflammatory cells increased further and degenerative muscle fibers were being replaced with centrally nucleated muscle cells. The average cross-sectional area non-grafted EDL and grafted muscle in the probiotic supplemented mice at day 7 increased to 48% and 23% (P = 0.002), respectively, compared with the respective values in the control animals. Whereas in non-grafted and grafted EDL muscle it could approach 8% and 36% (P = 0.008), respectively at 14 d compared with the corresponding values of the control EDL muscle transplants. The number of muscle fibers in the non-grafted and grafted probiotic-supplemented groups increased to12% and 20% (P = 0.045) at day 7 compared with the control EDL muscle. In non-grafted and grafted EDL muscle, the number of regenerated muscle fibers increased to 73% and 64% (P = 0.110) at day 14 compared with control EDL grafted muscle.
Results of the present study regarding better regeneration of skeletal muscle fibers in the probiotic-supplemented mice than the control grafts warrant further molecular-level investigation to understand the underlying mechanism mediating the process of skeletal muscle fiber regeneration. Probiotics possibly modulate the process of muscle fiber regeneration by adjusting the composition of gut microbiota.
本研究旨在探讨益生菌补充对移植后小鼠趾长伸肌（EDL）再生的影响。
将 EDL 肌肉在小鼠中进行异体移植。实验组在 EDL 肌肉移植手术后每天给予 1×10 菌落形成单位/g 体重的鼠李糖乳杆菌。从对照组和实验组的动物中回收 EDL 肌肉移植后 3、5、7 和 14 天的 EDL 肌肉移植，并进行组织学分析。
移植后第 3 天，炎性细胞已浸润移植的 EDL 肌肉，移植组织的中心部分含有坏死纤维。移植后第 5 天，炎性细胞浓度进一步增加，退行性肌纤维被中央有核肌细胞取代。与对照组相比，益生菌补充组在第 7 天的非移植 EDL 和移植肌肉的平均横截面积分别增加到 48%和 23%（P=0.002）。而在非移植和移植 EDL 肌肉中，分别在第 14 天接近 8%和 36%（P=0.008）。与对照组 EDL 肌肉移植相比，非移植和移植的益生菌补充组的肌纤维数量在第 7 天分别增加到 12%和 20%（P=0.045）。在非移植和移植 EDL 肌肉中，再生肌纤维的数量在第 14 天分别增加到 73%和 64%（P=0.110），与对照组 EDL 移植肌肉相比。
与对照组移植相比，益生菌补充组的骨骼肌纤维再生更好，本研究的结果表明，有必要进一步进行分子水平的研究，以了解介导骨骼肌纤维再生过程的潜在机制。益生菌可能通过调节肠道微生物群的组成来调节肌肉纤维再生过程。
