Effect of synbiotics on radiation-induced reactions and intestinal microbiota during extenal beam radiation therapy in patients with prostate cancer

Background. External beam radiation therapy (eBRt) is one of the primary treatment modalities for patients with prostate cancer. Despite advancements in radiotherapy technology and planning, significant challenges in managing radiation-induced reactions remain. In this regard, the search and development of new drugs to mitigate side effects from radiotherapy is a critical research area. 
The purpose of the study was to evaluate the effect of synbiotics (VedaBiotic, Phytolysate Gastro, Phytolysate and urological) on the development of radiation-induced bladder and bowel reactions, as well as to study the state of gut microbiota during eBRt in prostate cancer patients. 
Material and Methods. The study included 15 patients diagnosed with stage t3–4n0M0 prostate cancer (adenocarcinoma) receiving eBRt at Radiotherapy Department of novosibirsk Regional Clinical Oncology Center. From november 2024 to December 2024, patients received 3D conformal radiation therapy delivered to the prostate, seminal vesicles, and pelvic lymph nodes at single doses of 2.5/2.5/1.8 Gy to total doses of 80/80/50 Gy in 28 fractions, respectively. Patients used synbiotics as the dietary supplement during radiation therapy in accordance with the instructions on the label. all patients underwent maximum androgen blockade including chemical castration with lHRH agonists. 
Results. A survey of patients showed reduction in nocturia to 2–3 episodes per night. there was also a decrease in urination discomfort and the absence of symptoms of flatulence. PCR analysis detected an increase in beneficial bacteria, namely lactobacillus and Bifidobacterium species (lacto-bifidobacteria), and Faecalibacterium prausnitzii, indicating a restoration of a healthy balance in the intestinal microflora. 
Conclusion. the results obtained show that the inclusion of synbiotics (VedaBiotic, Phytolysate Gastro, Phytolysate and urological) in the diet can reduce dysuric symptoms, flatulence, and help restore intestinal microflora balance in patients receiving eBRt to the prostate, seminal vesicles, and pelvic lymph nodes.

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