Microbiota-nutrition sequential therapy for refractory radiation proctitis: A case report

Abstract

BACKGROUND

Gut dysbiosis is closely associated with radiation-induced intestinal injury. This study aimed to preliminarily assess the efficacy and safety of fecal microbiota transplantation (FMT) combined with immunomodulatory enteral nutrition (IEN) for the treatment of refractory radiation proctitis.

CASE SUMMARY

A 49-year-old woman with prior cervical cancer treated by hysterectomy 4 years earlier presented with left inguinal lymphadenopathy. Following radiotherapy, the patient experienced lower abdominal pain, diarrhea, and hematochezia, diagnosed as radiation enteritis. The patient underwent two FMT with adjunctive IEN support. Symptoms alleviated from Common Terminology Criteria for Adverse Events grade 3 proctitis to grade 2 after the first FMT, and further to grade 1 after the second. Nutritional and immune indices improved obviously: Body mass index (20.28 kg/m²→24.34 kg/m²), total protein (63.7 g/L→73.7 g/L), albumin (35.8 g/L→40 g/L), lymphocyte count (0.94× 10⁹/L→1.37 × 10⁹/L) and lymphocyte percentage (18.2%→34.8%) rose, while procalcitonin dropped from 0.07 ng/mL to 0.03 ng/mL. The Vienna Rectoscopy Score declined from 25 to 16 post-FMT1 and 5 post-FMT2. Pro-inflammatory cytokines tumor necrosis factor-α (2.29 pg/mL→1.51 pg/mL), interferon (IFN)-γ (0.73 pg/mL→0.16 pg/mL) and interleukin (IL)-6 (9.40 pg/mL→3.60 pg/mL) decreased significantly, while anti-inflammatory IL-4 (0.97 pg/mL→1.16 pg/mL) and IL-10 (0.70 pg/mL→0.86 pg/mL) slightly increased. IL-2 and IL-1β rose mildly, and IL-8 elevated moderately. Sequential FMT restored gut Shannon diversity; principal coordinates analysis verified microbiota remodeling close to donor profiles, with reduced Escherichia-Shigella and enriched beneficial genera Faecalibacterium, Bacteroides and Ruminococcus.

CONCLUSION

In this patient, FMT combined with immunomodulatory nutrition was associated with restoration of gut microbiota, alleviation of symptoms, and improvement in nutritional and immune parameters in refractory radiation proctitis, suggesting a potential therapeutic strategy that warrants further validation.

Keywords: Radiation proctitis; Fecal microbiota transplantation; Gut microbiome; Immunomodulatory enteral nutrition; Gut barrier function; Case report

Core Tip: This case demonstrates that combining fecal microbiota transplantation (FMT) with immunomodulatory enteral nutrition can achieve sustained clinical remission in refractory radiation proctitis after only two FMT courses, outperforming previous FMT-alone reports that required 4-7 sessions. The concurrent restoration of gut microbiota diversity, enrichment of beneficial genera (Faecalibacterium, Ruminococcus, Bacteroides), and downregulation of pro-inflammatory cytokines suggest a synergistic effect of nutritional support and microbial reconstruction in radiation-induced intestinal injury. These preliminary observations, however, warrant confirmation in larger prospective studies.