The Lactulose Breath Test Can Predict Refractory Gastroesophageal Reflux Disease by Measuring Bacterial Overgrowth in the Small Intestine

Objective: The diagnosis of RGERD in patients typically involves 24-hour esophageal pH monitoring, but due to its invasiveness and low patient compliance, new screening methods are needed. In this study, a lactulose breath test (LBT) was conducted to detect the growth of small intestine bacteria (SIBO) and explore the potential relationship between LBT and RGERD to identify a new treatment method for RGERD. Methods: A total of 178 patients with gastroesophageal reflux were enrolled from June 2020 to December 2022 in the Gastroenterology Department, Building 3, the First Affiliated Hospital of Kunming Medical University; these patients included 96 patients with nonrefractory GERD (NRGERD) and 82 patients with RGERD. The Gerd Q score, reflux symptom index (RSI) score, gastroscopy results, clinical symptoms, and other related indicators were collected. Statistical methods were used to analyze the gathered data. Results: The incidence of acid reflux and heartburn in patients with RGERD was significantly greater than that in patients with NRGERD (67.10% vs. 42.70%, P <0.01 and 65.00% vs. 34.40%, P <0.01). The CH 4 values of patients with RGERD were significantly greater than those of patients with NRGERD at each time point, and there was a correlation between the CH 4 values at 60 min and RGERD ( P <0.05). For patients with RGERD, the incidence of abdominal pain, acid regurgitation, and heartburn was greater in the CH 4 -positive group than in the CH 4 -negative group (61.90% vs. 57.50%, 69.05% vs. 65.00%, 69.05% vs. 57.50%, P >0.05). The incidence of nausea was also greater in the CH 4 -positive group than in the CH 4 -negative group (61.90% vs. 35.00%, P <0.05). Conclusion: Increased CH 4 levels are correlated with RGERD. In addition, patients with RGERD may develop SIBO after long-term use of PPIs, and interventions involving SIBO could provide new ideas for the treatment of RGERD.