Interleukin-8 production by polymorphonuclear leukocytes from patients with chronic infected leg ulcers treated with Lactobacillus plantarum

Bacterial infection impairs the healing process, promoting the chronicity of inflammation and wounds. Because antibiotics fail to eradicate bacteria, especially in biofilm form, new therapeutic modalities may be required. In the present study, the effectiveness of bacteriotherapy with Lactobacillus plantarum on infected chronic venous ulcers was investigated and its effects on interleukin (IL)-8 production by cells from the ulcer bed and neutrophils isolated from peripheral blood that were previously challenged in vitro with Pseudomonas aeruginosa and L. plantarum were studied. Topical application of L. plantarum culture to lesions (25–60 cm2) of 14 diabetic and 20 non-diabetic patients induced debridement, granulation tissue formation and total healing after 30 days in 43% diabetics and in 50% non-diabetics. No significant differences between the groups were observed. The cells from ulcer beds collected after treatment with L. plantarum for 10 days showed a decrease in the percentage of polymorphonuclear, apoptotic and necrotic cells and an enhancement of IL-8 production. IL-8 production by isolated neutrophils from these patients was compared with that in diabetics without ulcers, as well as normal subjects under basal conditions, and after infection of polymorphonuclear cells with P. aeruginosa preincubated either with or without L. plantarum. The basal values in diabetic and ulcer patients were higher than normal (p <0.001) and were increased by P. aeruginosa infection in normal, diabetics (p <0.001) and non-diabetics with ulcers (p <0.01). Preincubation with L. plantarum decreased IL-8 production in patients with ulcers non-diabetic and diabetic (p <0.001). Lactobacillus plantarum treatment reduced wound bacterial load, neutrophils, apoptotic and necrotic cells, modified IL-8 production and induced wound healing.