Comparison of the effects of stent-based diversion technique versus prophylactic double-lumen ileostomy on intestinal flora in postoperative patients with rectal cancer

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• Picked for Microbiology (medical) (top studies of the week, 9 August 2026): Stent‑based diversion vs ileostomy alters postoperative intestinal flora

Abstract

BACKGROUND: The stent-based diversion technique (SDT), as a novel surgical approach for reducing anastomotic leakage (AL) following low anterior resection (LAR), achieving effective intestinal diversion while avoiding ileostomy and subsequent stoma reversal surgery. Although multicenter randomized controlled trials have demonstrated the safety of SDT, the alterations in postoperative intestinal microbiota following SDT remain inadequately characterized. METHODS: This study enrolled 40 patients with mid-low rectal cancer (21 SDT, 19 PDI). Rectal swab samples were collected preoperatively and at 3 weeks and 3 months postoperatively (n = 120) for metagenomic sequencing. α- and β-diversity analyses were performed to compare microbial community characteristics. LEfSe was used for differential analysis of species and KEGG functional pathways. Postoperative clinical outcomes including AL and anastomotic stricture (AS) were assessed. RESULTS: The SDT group showed a significantly lower incidence of AS compared with the PDI group (4.76% vs. 31.58%, p < 0.05). Preoperative α- and β-diversity were comparable between groups. Postoperatively, the SDT group exhibited higher microbial richness at both 3 weeks and 3 months (both p < 0.05). In the PDI group, the α-diversity showed a continuous decline from 3 weeks to 3 months postoperatively compared with the preoperative baseline (p < 0.05). However, the SDT group demonstrated no significant decrease in α-diversity at 3 weeks (p > 0.05), but did at 3 months (p < 0.05). Significant intergroup β-diversity divergence emerged from 3 weeks onward (both p < 0.05). The SDT group showed significant structural changes from 3 weeks to 3 months (p < 0.05), whereas the PDI group remained stable. At 3 weeks, opportunistic pathogens (e.g., Parvimonas micra) were enriched in the PDI group, while the SDT group enriched beneficial taxa (e.g., Akkermansia). By 3 months, the PDI group exhibited enrichment of oral/genitourinary-derived bacteria (Prevotellaceae, Porphyromonas, Fusobacterium), whereas the SDT group showed higher abundance of beneficial Bacteroidota (e.g., Phocaeicola vulgatus). Functionally, the SDT group enriched amino acid and carbohydrate metabolism pathways, while the PDI group enriched translation and energy metabolism pathways. CONCLUSION: We found that SDT better preserves postoperative gut microbiota diversity, promotes the restoration of beneficial bacteria, and influences microbial functional pathways, thereby establishing a more favorable microbiome environment for patients.

Abstract as published, via PubMed.