Breast Microbiome Dysbiosis in Plasma Cell Mastitis: A Ribosomal RNA Gene Sequencing Study.

Plasma cell mastitis (PCM) is a chronic breast condition with limited effective treatment options. Surgical intervention is a standard treatment approach but may be associated with postoperative complications. Recent studies suggest that alterations in the microbiome may be associated with the onset, progression, and recurrence of PCM. In this study, high-throughput 16S ribosomal RNA (rRNA) gene sequencing was used to compare the breast tissue microbiota of patients with PCM with that of the non-PCM control (NC) group. A total of 86 participants were enrolled. No significant differences were observed between the groups in age, body mass index (BMI), or lymphocyte count, whereas white blood cell (WBC) count, neutrophil count, prolactin level, and the prevalence of nipple inversion differed significantly between the groups. A total of 214 bacterial genera showed nominally significant differences in relative abundance between the two groups based on unadjusted P values. Staphylococcus and Bacteroides were more abundant in the PCM group, whereas Plesiomonas and Acinetobacter were more abundant in the NC group. These results indicate that the breast tissue microbiota differed between the PCM and NC groups. The findings demonstrate alterations in the breast microbiome associated with PCM and provide a basis for further investigation of their potential relevance to PCM and future treatment strategies.