Comparative microbiome analysis of contracted breast capsules: a cross-sectional study.

[BACKGROUND] Despite the implication of bacterial biofilms in the etiology of capsular contracture, there is limited research on the microbial structure of the contracted capsule. Moreover, the potential role of the skin microbiome in capsular contracture remains undefined. Therefore, we conducted this study to characterize the microbiome of the breast capsular contracture by comparing it with the microbiome of biopsy without capsular contracture. We also investigated the associations between the microbial structures of the skin surrounding the breast and those of the breast capsule.

[RESULTS] We collected 25 capsules, including 14 samples without capsular contracture and 11 samples with capsular contracture. Beta diversity analysis demonstrated that the microbial structures in the breast capsules were distinctly different from those in the skin. The capsular microbiota was more influenced by individual variation than by the progression of the capsular contracture. Breast capsules with capsular contracture showed a higher relative abundance of Staphylococcus, correlating positively with total bacterial load.

[CONCLUSIONS] Capsular contracture is associated with an escalation in total bacterial load and an increase in the abundance of opportunistic pathogens, such as Staphylococcus. This comparative analysis of contracted breast capsules emphasizes the management of pathogens, considering bacterial load, in the occurrence of capsular contracture.