Clinical Utility and Diagnostic Yield of Duodenal Versus Jejunal Aspirates for Small Intestinal Bacterial or Fungal Overgrowth.

BACKGROUND AND AIMS: Small intestinal bacterial (SIBO) or fungal overgrowth (SIFO) involves excessive microbial growth in the small intestine. While jejunal aspirate is the gold standard for diagnosis, duodenal aspiration is easier to perform. This study determined and compared the diagnostic yield of tandemly performed duodenal and jejunal aspirates and cultures.

METHODS

Patients with gas and bloating symptoms and suspected SIBO/SIFO underwent enteroscopy, during which duodenal and jejunal aspirates were sequentially collected using a 2 mm Liguory catheter under aseptic conditions. Cultures were performed for aerobic, anaerobic, and fungal organisms. The endoscopic time, diagnostic yield, and concordance rates were compared.

RESULTS

Of 57 patients, 24 (42%) had positive cultures for SIBO and SIFO with diagnostic yield of 33% for both duodenal and jejunal aspirates. The overall concordance rate between duodenal and jejunal aspirates was 82% (47/57), with Cohen's kappa of 0.61. Among positive cases, the concordance was 58% (14/24). Using jejunal aspirates as the gold standard, duodenal aspirates had a sensitivity of 74%, specificity of 87%, positive predictive value of 74%, and negative predictive value of 87%. Aerobes predominated (79%), with 15% anaerobes and 6% fungi. Common aerobes included Streptococcus, Haemophilus, Klebsiella, Rothia, and Neisseria, and anaerobes included Clostridium and Bacteroides, with similar prevalence at both sites. Jejunal aspiration took significantly longer to perform than duodenal (p < 0.001).

CONCLUSION

Duodenal and jejunal aspirates have comparable diagnostic yields for detecting SIBO/SIFO. With similar microbial profiles but shorter procedural time, duodenal aspirates offer a practical and efficient alternative for routine evaluation although may miss diagnosis.