No abstract

No abstract

Background Prior to antireflux surgery, most patients with symptoms of gastroesophageal reflux disease (GERD) have been taking long-term proton pump inhibitors (PPIs). PPIs have been shown to cause changes to the intestinal microbiota, such as small intestinal bacterial overgrowth (SIBO), which is characterised by symptoms of gas bloating. Patients undergoing antireflux surgery are not routinely screened for SIBO, yet many patients experience gas-related symptoms postoperatively. Methods Data from consecutive patients (n = 104) referred to a speciality reflux centre were retrospectively assessed. Patients underwent a routine diagnostic workup for GERD including history, endoscopy, oesophageal manometry and 24-h pH-impedance monitoring off PPIs. Intestinal dysbiosis was determined by hydrogen and methane breath testing with a hydrogen-positive result indicative of SIBO and a methane-positive result indicative of intestinal methanogen overgrowth (IMO). Results 60.6% of patients had intestinal dysbiosis (39.4% had SIBO and 35.6% had IMO). Patients with dysbiosis were more likely to report bloating (74.6% vs 48.8%; P = 0.01) and belching (60.3% vs 34.1%; P = 0.01). The oesophageal acid exposure time and number of reflux episodes were similar between dysbiosis and non-dysbiosis groups, but patients with dysbiosis were more likely to have a positive reflux-symptom association (76.2% vs 31.7%; P < 0.001), especially for regurgitation in those with SIBO (P = 0.01). Hydrogen gas production was significantly greater in patients with a positive reflux-symptom association for regurgitation (228.8 ppm vs 129.1 ppm, P = 0.004) and belching (mean AUC 214.8 ppm vs 135.9 ppm, P = 0.02). Conclusions The prevalence of intestinal dysbiosis is high in patients with GERD, and these patients are more likely to report gas-related symptoms prior to antireflux surgery. Independently, SIBO may be a contributory factor to refractory reflux symptoms and gas bloating in antireflux surgery candidates.

Background Hydrogen and methane breath tests (HMBT) are widely used clinical investigations but lack standardization. To address this, the North American Consensus (NAC) group published evidence-based recommendations for HMBT. Aims To evaluate results obtained using NAC recommendations for HMBT, compared to retrospective data that utilized guidelines previously recommended. Methods HMBT data from 725 patients referred for small intestinal bacterial overgrowth (SIBO) and/or carbohydrate malabsorption (CM) testing were analyzed. Data were compared regarding dose of substrate for SIBO testing (16 vs. 10 g lactulose, and 50 vs. 75 g glucose) and the effect of post-ingestion sampling period for malabsorption testing. The effect of different recommended cut-off values for SIBO were examined. Results Substrate dose did not affect methane production. 10 g lactulose significantly reduced positive SIBO results compared to 16 g lactulose (42 vs. 53%, p = 0.04). 75 g glucose significantly increased positive results compared to 50 g glucose (36 vs. 22%, p = 0.04). Provoked symptoms were significantly more prevalent in patients testing positive by both North American Consensus and Ledochowski cut-off values. 34.5% of patients tested positive for CM at 180-min compared to 28% at 120-min (not significant, p = 0.19). Conclusions and Inferences 10 g lactulose substrate produces fewer positive SIBO results than 16 g lactulose, while 75 g glucose dose produces more positive SIBO results than 50 g. Performing CM breath tests for 180 min increases number of positive results when compared to 120 min. SIBO cut-off timings require further investigation, but our findings broadly support the NAC recommendations for SIBO and CM testing.

No abstract