Gut microbiota in patients with recurrent deep infiltrating endometriosis

There are more and more publications on the role of the gut microbiota (GM) in the development of endometriosis in the current literature. However, the influence of GM and its composition on disease recurrence remains understudied. Objective. To study the characteristics of GM in patients with recurrent deep infiltrating endometriosis (DIE). Patients and methods. A prospective comparative study was conducted. The study group included 32 reproductive-aged patients with recurrent DIE, the comparison group – 51 patients without disease recurrence within one year after the first operation. Clinical and anamnestic analysis, questionnaires using a visual-analog scale to measure pelvic pain syndrome, and examination of GM composition by a real-time quantitative PCR were performed. Results. Patients with recurrent DIE were significantly more likely to report chronic pelvic pain (85.7%; 28/32 vs 66%; 34/52, p = 0.034), dyspareunia (40.6%; 13/32 vs 39.2%; 20/51; p = 0.004), dyschezia (18.8%; 6/30 vs 9.8%; 5/51; p = 0.024); they more often had chronic gastritis and irritable bowel syndrome, (71.9% (23/32) vs 51.3% (26/51); p = 0.006). Patients in the study group showed a significant decrease in taxonomic diversity (12.4(4.5) vs 14.0(2.7); p = 0.001), an increase in the Bacillota/Bacteroidota ratio (1.15(0.20) vs 0.48(0.15); p = 0.038), a decrease in GM spectrum of symbiont bacteria of the Bacteroidales family and Actinomycetota commensal microorganisms, which is associated with increased GM colonization by Bacillota type bacteria, as well as opportunistic facultative-anaerobic microorganisms. Conclusion. The recurrence of endometriosis is accompanied by functional gastrointestinal (GI) disorders, the manifestations of which persist after surgical treatment and are associated with a decrease in the species and taxonomic diversity of GM, an increase in the Bacillota/Bacteroidota ratio, the number of pathobionts, and a decrease in the number of commensal bacteria. The correction of functional GI disorders, aimed at harmonizing GM, can be considered as a preventive measure against disease recurrence. Key words: deep infiltrating endometriosis, gut microbiota, disease recurrence