Avaliação dos efeitos da administração oral do probiótico Bifidobacterium longum 51A na cicatrizaçao de feridas cutâneas excisionais em camundongos

Abstract

Skin tissue repair involves a cascade of events ranging from inflammation to the formation of fibrovascular tissue and remodeling of the new matrix. Our group has demonstrated that the skin's commensal microbiota influences the healing of skin wounds and that probiotics from the Lactobacillus genus promote skin health. The influence on healing of bacteria of the genus Bifidobacterium, however, is still unknown. The objective of this study was to evaluate the effects of oral administration of the probiotic Bifidobacterium longum 51A (BL51A) on the healing of cutaneous excisional wounds in mice. Male Swiss mice (8 weeks old) were used. The treated group received the probiotic BL51A, which was administered daily by gavage at a dose of 107 microorganisms for 14 days after creating the wounds. The control group received PBS vehicle (100 μL). The experimental model consisted of creating four skin wounds in the dorsal region and measuring the area throughout the experimental period using a digital caliper. Histomorphometric parameters were also evaluated (epithelial tongue length, granulation tissue area, scar tissue area), mast cell degranulation, activity of the enzymes myeloperoxidase/MPO and N-acetyl-b-D- glucosaminidase/NAG (for indirect analysis of the presence of neutrophils and macrophages, respectively), levels of inflammatory cytokines (TNF, CXCL-1,CCL-2) and angiogenesis parameters (VEGF, capillary density), analysis of total collagen and organization of collagen fibers in the wound bed. No difference was observed in the rate of wound closure between the treated and control groups throughout the experimental period, but the treated group had lower levels of TNF, a greater number of capillaries and the scar's collagen fibers appeared to be in a more intertwined arrangement. A larger inoculum of Bifidobacterium longum 51A (109 microorganisms per gavage) also did not change the rate of wound closure. Our data suggest that oral administration of Bifidobacterium longum 51A, despite not altering the speed of wound closure, favors processes that are important to stimulate successful healing, such as angiogenesis, control of inflammation and better organization of fibers of collagen.