Breast Microecology Improvement Using Probiotics Following Needle Aspiration in Patients With Lactational Breast Abscess: a Multi-center Randomized Double-blind Controlled Trial

Abstract Background: Studies show that oral probiotics can improve the breast microecology and thus alleviate the inflammatory response; however, there is a lack of experimental data corresponding to cases with existing abscesses. We aimed to investigate the effect of Lactobacillus fermentum CECT5716 during needle aspiration in patients with lactational breast abscesses.Methods: 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 day-5 of treatment, delactation rate, relieving pain rate, and the number of needle aspirations until day-28.Results: The experimental group’s 5-day cure rate (43.1%, 22/51) was significantly higher (p<0.05). The breastfeeding continuation on day-5 did not differ significantly (experimental group: 88.2%, 45/51; control group: 96.0%, 48/50; 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). The median number of needle aspirations up to day-28 was two in the experimental (1–3 times) and control (1–4 times) groups, with no statistically significant differences (Mann–Whitney U test, p=0.322). Four patients in each group developed diarrhea, with adverse reaction rates of 7.84% (4/51) and 8.0% (4/50), respectively. No adverse reactions were reported in the infants.Conclusion: 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: May 6, 2020.