Microbial Symbionts Accelerate Wound Healing via the Neuropeptide Hormone Oxytocin
(a) Compression of the wound healing cascade in L. reuteri-treated mice results in neutrophil departure by day 6 and the beginning of collagen deposition showing advanced healing. Control animals wounds' remain populated with neutrophils and other innate immune cell infiltrates, indicative of a comparatively early stage of wound healing. (b) Histopathology of the granulation tissue in wounds of male mice. Early granulation tissue in control mice characterized by activated plump fibroblasts, (c) minimal amount of collagen, and (d) abundant neutrophils with (e) small numbers of Treg cells. The granulation tissue of mice fed L. reuteri is more mature with (b) elongated fibroblasts and a chronic inflammatory component (lymphocytes), (c) increased collagen deposition, and (d) small numbers of neutrophils and (e) abundant Treg cells. (6 day: Male: Control (n = 12), Control + LR (n = 12); Female: Control (n = 12), Control + LR (n = 12)). (b) Hematoxylin and Eosin. (b) Masson's Trichrome. (d) and (e) Immunohistochemistry: Diaminobenzidine chromogen, Hematoxylin counterstain. Scale bars = 50 µm.