Background: Helicobacter pylori infection has been reported to lead to post-operative complications after bariatric surgery (BS), especially marginal ulcers. The optimal method for pre-operative screening is yet to be determined. Objective: To analyze the diagnostic accuracy of the endoscopic urease test for the detection of H. pylori in individuals undergoing BS and the main endoscopic and histological changes within this population. Methods: A cross-sectional study was carried out based on a database from medical records of 232 individuals who underwent BS between 2016 and 2019 at a tertiary university hospital. Clinical, anthropometric, and endoscopic data were analyzed. The gold-standard method considered to calculate diagnostic accuracy variables was histopathological examination through hematoxylin-eosin/Giemsa stains. Results: 87.5% of the participants were female; mean age was 38.5±9.5 years and average body mass index was 37.6±3.8 kg/m2. The commonest endoscopic finding was gastritis (50.9%) with a predominance of the mild erosive form (25%). Upon histological examination, 59.1% of the participants had confirmed H. pylori infection. H. pylori infection was associated with higher frequencies of endoscopic duodenitis (23.4% vs 12.6%; P=0.04), histological chronic gastritis (100% vs 56.8%; P<0.0001) and histological acute gastritis (58.4% vs 2.1%; P<0.0001). The urease test had a sensitivity of 79.6% and a specificity of 97.9%, leading to an overall accuracy of 87.1%. Conclusion The endoscopic urease test is highly accurate for pre-operative screening of H. pylori infection in individuals who undergo BS. H. pylori infection was significantly associated with endoscopic (duodenitis) and histopathological (chronic and active gastritis) changes.

BACKGROUND: A possible direct link between nonalcoholic fatty liver disease (NAFLD) and Helicobacter pylori ( H. pylori ) infection has recently emerged. OBJECTIVE: This study aimed to analyze associations between the presence of histologically demonstrated NAFLD aspects with H. pylori infection in individuals with obesity undergoing bariatric surgery. DESIGN AND SETTING: An observational analytical cross-sectional study was conducted based on data collected from the medical records of individuals undergoing bariatric surgery at a tertiary university hospital in 2019. METHODS: NAFLD was assessed through histological examination of wedge liver biopsies collected during the proceedings. H. pylori infection was analyzed through the association of the urease test and histological examination performed in biopsies routinely collected during preoperative esophagogastroduodenoscopy. RESULTS: Of the 88 participants, 85% were female, and the average age was 39.1 ± 8.4 years. H. pylori infection was present in 61.4% of the patients. The mean body mass index was 36.6 ± 3.4 kg/m 2 . The most prevalent histopathological aspects of NAFLD were macrovesicular steatosis (92%), hepatocellular ballooning (92%), lobular inflammation (93.2%), portal inflammation (96.6%), and fibrosis (93.2%). No histopathological aspect of NAFLD was found to be significantly associated with H. pylori infection. CONCLUSION: In this study population, H. pylori infection was not significantly associated with the histopathological aspects of NAFLD in individuals with obesity undergoing bariatric surgery.