Prevalence of small intestinal bacterial overgrowth in patients with gastroparesis: a systematic review and meta-analysis.

Aim: We performed a systematic review and meta-analysis to identify the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with gastroparesis. Background: Several studies have suggested an association between SIBO and gastroparesis, which is characterized by delayed gastric emptying in the absence of mechanical obstruction. Methods: A comprehensive search was performed using MEDLINE, EMBASE, Scopus and Cochrane Central Register of Controlled Trials (CENTRAL) through January, 2022 for randomized controlled trials and observational studies reporting the prevalence of SIBO in gastroparesis. Pooled prevalence was estimated using a random effects model. Heterogeneity was assessed by using the inconsistency index (I2). Results: Among the 976 articles identified, 43 studies were selected for full text review. Six studies, with 385 patients, were deemed eligible for inclusion, with a perfect agreement between investigators (kappa=1.0). Overall, 379 patients were diagnosed with gastroparesis by gastric emptying scintigraphy and six were diagnosed with a wireless motility capsule. The pooled prevalence of SIBO was 41% (95% confidence interval 0.23-0.58). SIBO was diagnosed using jejunal aspirate cultures (N=15, 8.4%), lactulose breath test (N=80, 44.7%), glucose breath test (N=30, 16.8%), D-xylose breath test (N=52, 29.1%), and hydrogen breath test (N=2, 1.1%). Heterogeneity was significant and noted to be high at 91%. Only one study reported SIBO diagnosis in controls, therefore no pooled odds ratio was calculated. Conclusion: SIBO was present in almost half of the patients with gastroparesis. Future studies should examine and identify the association between SIBO and gastroparesis.