The goal of this clinical trial is to investigate the efficacy and safety of Weifuchun tablet in treating gastric intestinal metaplasia in Helicobacter pylori-negative adults. The main questions it aims to answer are: Does Weifuchun tablet promote the regression of gastric intestinal metaplasia in individuals without Helicobacter pylori infection? What medical problems do participants experience when taking Weifuchun tablet? Researchers will compare the effectiveness of Weifuchun tablet in treating gastric intestinal metaplasia with that of folic acid, as suggested by the Chinese consensus on management of gastric epithelial precancerous conditions and lesions (2020). Participants will: Take Weifuchun tablets or folic acid every day for 6 months. Visit the clinic once every 4 weeks for checkups and tests.

Inclusion Criteria:

• patients aged from 18 to 75 years old.
• patients with OLGIM stage Ⅱ-Ⅳ diagnosed by upper gastrointestinal endoscopy and histopathological examination within the last 3 months.
• patients without Helicobacter pylori infection, including patients who had successful Helicobacter pylori eradication before enrollment.

Exclusion Criteria:

• a history of regular use (defined as at least once per week) of non-steroidal anti-inflammatory drugs (NSAIDs) and/or statins.
• a history of stomach surgery (including endoscopic submucosal dissection and endoscopic mucosal resection) or previously diagnosed malignant tumor.
• a history of heart failure, renal failure, liver cirrhosis or chronic hepatic failure; patients with contraindications or allergies to the drugs in this study.
• breastfeeding or pregnancy.
• a history of substance abuse or alcohol abuse within the past one year.
• patients with severe mental illness.
• refusal to undergo drug treatment.
• refusal to sign informed consent.