Gut Microbiota Changes After Hormonal or Surgical Treatment for Endometriosis

Abstract Purpose Although studies have suggested a link between gut microbiota and endometriosis pathophysiology, the effects of treatment for endometriosis remain unclear. Methods In this prospective observational study, 27 patients with stage III/IV endometriosis and 17 healthy controls provided a total of 56 fecal samples. In endometriosis patients, gut microbiota profiles were analyzed before and after hormonal therapy or surgery to assess treatment‐related changes. 16S rRNA gene sequencing was used for microbiota analysis. Results No differences in α‐ or β‐diversity were observed between the endometriosis and control groups, although patients with endometriosis had high levels of Acidaminococcus, Lachnoclostridium, and Paraprevotella and low levels of Odoribacter (all p < 0. 05). Among the eight patients who received hormonal therapy, no significant changes in α‐ and β‐diversity were observed between the pre‐ and post‐treatment samples. A comparison of samples from the same individuals showed an increase in Blautia, which is associated with mental health stability, and a decrease in Sutterella, which is involved in regulating the intestinal barrier. In an exploratory analysis of patients without recurrence after surgery (n = 4), α‐diversity significantly increased (p = 0. 035), with stable β‐diversity. Postsurgical increases were observed in 10 genera, including six inflammation‐related taxa; five (Flavonifractor, Eubacteriumbrachygroup, Hungatella, IncertaeSedis, and Fournierella) are associated with anti‐inflammatory effects. Conclusions Hormonal therapy for endometriosis may help not only to control lesions but also to support mental health. Surgical treatment may alter the composition of inflammation‐associated gut bacteria; however, these exploratory results from a small cohort should be interpreted with caution. Further studies with larger sample sizes are warranted.