Abstract: Objective To understand the changes in the gut microbiota during small bowel obstruction, thereby providing a theoretical basis for guiding anti-infective therapy in affected patients.Methods From August 2022 to August 2024, 21 patients with small intestinal obstruction who were hospitalized and underwent nasal cannula insertion for intestinal obstruction.Intestinal fluid specimens of the small intestine were extracted through nasal intestinal obstruction catheters for 16S rRNA high-throughput sequencing to analyze the composition characteristics of intestinal flora in patients with small intestinal obstruction.Results (1)Streptococcus was the most prevalent genus (90.5%, 19/21), but Candida exhibited the highest mean relative abundance (75.9%).(2)A "fungal-bacterial" symbiotic pattern (Candida + Enterococcus/Klebsiella) was detected in 5 patients.(3)The elderly group (age ≥60 years) showed significantly higher abundances of Candida and Enterococcus versus the non-elderly group (P<0.05).(4)Genus co-occurrence analysis revealed: Strong positive correlation between Candida and Enterococcus (r=0.82, P<0.001), Negative correlation between Streptococcus and Bacteroides (r=-0.71, P=0.002).Conclusion SBO patients exhibit significant age-related dysbiosis, with elderly patients characterized by a Candida-Enterococcus symbiotic pattern.Early fungal surveillance and prophylactic anti-infective therapy are recommended for patients aged ≥60 years.

Key words: intestinal obstruction; microbiota; high-throughput nucleotide sequencing