The characteristics of small intestinal bacterial overgrowth in patients with gallstone diseases

Abstract Background and Aim Small intestinal bacterial overgrowth (SIBO) might be prevalent in gallstone disease, including cases involving cholecystectomy and gallstones. The study aimed to investigate the prevalence and characteristics of SIBO in patients with gallstone disease. Methods This prospective study evaluated 265 patients for gallstone disease (200, gallstones; 65, cholecystectomy) and 39 healthy controls. Laboratory data, abdominal ultrasonography, and glucose breath test (GBT) with bowel symptom questionnaire were performed. Results Glucose breath test positivity (+) in patients with gallstone disease (36.6%) was significantly higher than that in controls (20.5%). GBT+ in the gallstone group (40.5%) was significantly higher than that in the control or cholecystectomy group (24.6%). The number of patients with gallstone, tend to be higher in the GBT (H 2 )+, (CH 4 )+, and (mixed)+ groups (56 [28.0%], 11 [5.5%], and 14 [7.00%]), respectively. Gallbladder disease was independently associated with fatty liver, metabolic syndrome, and SIBO. Of 97 GBT+ patients, 70 (72.1%), 12 (12.4%), and 15 (15.5%) were in the GBT (H 2 )+, (CH 4 )+, and (mixed)+ groups, respectively. GBT (CH 4 )+ or GBT (mixed)+ were significantly associated with the gallstone group compared with the cholecystectomy group. The GBT (mixed)+ group had higher total symptom scores than the GBT− group for hard stool and urgency tendency, or the GBT (H 2 )+ group in hard stool and loose stool tendency. Gallstone was the only independent factor for SIBO in patients with gallstone diseases. Conclusions Small intestinal bacterial overgrowth is common among patients with gallstone. Especially, CH 4 or mixed‐type SIBO seems to be prevalent and to worsen intestinal symptoms.