Breast microecology improvement using probiotics following needle aspiration in patients with lactational breast abscess: a multi-center randomized double-blind controlled trial

Although oral probiotics can improve breast microecology and alleviate the inflammatory response, there are no data regarding cases with existing abscesses. We aimed to investigate the effect of Lactobacillus fermentum CECT5716 during needle aspiration in patients with lactational breast abscesses. Patients (aged 20–41 years) with lactational single-cavity breast abscesses (diameter 3–6 cm) from 12 hospitals were randomly assigned to the experimental (n = 51) and control groups (n = 50). Outcome measures included the abscess cure rate on treatment day-5, delactation rate, relieving pain rate, and number of needle aspirations until day-28. The experimental group’s 5-day cure rate (43.1%) was significantly higher (p < 0.05). Breastfeeding continuation on day-5 did not differ significantly (experimental group: 88.2%, control group: 96.0%, p = 0.269). In the experimental and control groups, 19.6% and 14.0% of patients experienced moderate to severe pain on day-5, respectively, with no statistically significant differences (p = 0.451). Four patients in each group developed diarrhea, with adverse reaction rates of 7.84% and 8.0%, respectively. No adverse reactions were reported in the infants. L. fermentum can shorten the healing time in patients with lactational breast abscesses. Trial registration This study was registered in the Chinese Clinical Trial Registry (http://www.chictr.org.cn), registration number: ChiCTR2000032682, registration date: 6/May/ 2020; first entry date: 11/May/2020.