AbstractPrevious studies have suggested that Helicobacter pylori (H. pylori) infection is associated with nonalcoholic fatty liver disease (NAFLD). The purpose of the present study was to investigate the effect of H. pylori eradication treatment on NAFLD patients. Two hundred NAFLD patients who tested positive for H. pylori infection were randomized into the H. pylori eradication treatment group or the control group. Metabolic and inflammatory parameters and FibroScan were measured in all subjects at baseline and 1 year after treatment. At 1 year after treatment, the decrease in metabolic indicators, such as fasting blood glucose, glycosylated haemoglobin, homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides, body mass index and controlled attenuation parameter values, were more obvious in the treatment group. Moreover, the inflammatory indicators white blood count and high-sensitivity C-reactive protein (hs-CRP) and the inflammatory factors interleukin 6 (IL-6) and tumour necrosis factor-α (TNF-α) were also significantly decreased. H. pylori eradication can further reduce the metabolic indices of NAFLD and the degree of liver steatosis. H. pylori infection may participate in the occurrence and development of NAFLD through its influence on inflammatory factors. Thus, checking for the presence of H. pylori infection in patients at risk of NAFLD may be beneficial.