Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB‐12 promote infected wound healing via regulation of the wound microenvironment

Abstract

Abstract Infected wounds can result in complex clinical complications and delayed healing, presenting a significant global public health challenge. This study explored the effects of topical application of two probiotics, Lactobacillus rhamnosus GG (LGG) and Bifidobacterium animalis subsp. lactis BB‐12, on the microenvironment of infected wounds and their impact on wound healing. LGG and BB‐12 were applied separately and topically on the Staphylococcus aureus (S. aureus)‐infected skin wounds of the rat model on a daily basis. Both probiotics significantly accelerated wound healing, demonstrated by enhanced granulation tissue formation and increased collagen deposition, with BB‐12 showing superior efficacy. LGG and BB‐12 both effectively inhibited neutrophil infiltration and decreased the expression of pro‐inflammatory cytokines tumor necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6). Notably, BB‐12 markedly reduced IL‐6 levels, while LGG significantly lowered TNF‐α, transforming growth factor‐β (TGF‐β) and vascular endothelial growth factor (VEGF). Additionally, both probiotics promoted macrophage polarization towards the anti‐inflammatory M2 phenotype. Microbiota analysis revealed that LGG and BB‐12 significantly decreased the abundance of pathogenic bacteria (e.g. Staphylococcus and Proteus) and increased the proportion of beneficial bacteria (e.g. Corynebacterium). Particularly, BB‐12 was more effective in reducing Staphylococcus abundance, whereas LGG excelled in promoting Corynebacterium growth. These findings suggest the ability of LGG and BB‐12 to modulate the wound microenvironment, enhance wound healing and provide valuable insights for the management of infected wounds.