Effect of Probiotics on Preventing the Recurrence of Colonic Adenomas After Endoscopic Mucosal Resection in Patients With Chronic Gastritis: A Randomized, Double-Blind, Placebo-Controlled Trial Protocol

INTERVENTION: Intervention group:Standard postoperative management plus Compound Lactobacillus Acidophilus Tablets: 2 tablets each time, three times daily, taken orally after meals.;Control group:Standard postoperative management plus matched placebo: It is completely identical to probiotics in appearance, packaging, smell and taste.; CONDITION: Colonic adenoma PRIMARY OUTCOME: 1‐year incidence of metachronous new colonic adenomas after surgery (new adenomas outside the original EMR sites, confirmed by colonoscopy and pathology); SECONDARY OUTCOME: 1‐year local recurrence rate after EMR (at the original EMR sites);Gut microbiota: changes in alpha diversity, beta diversity and key bacterial genera (16S rRNA sequencing of fecal samples at 0, 3, 6 and 12 months);Safety indicators: incidence of adverse events (abdominal distension, diarrhea, bleeding, perforation, etc.).;Serum inflammatory markers: LPS, hs‐CRP and IL‐6 (detected at 0, 3, 6 and 12 months); INCLUSION CRITERIA: 1.Aged 30 to 75 years old, without gender limitation. 2.Colonic adenomas detected by colonoscopy and successfully treated with EMR with no endoscopic residual lesions. 3.Postoperative pathological confirmation of at least one adenoma. 4.Chronic gastritis confirmed by gastroscopy (manifested as mucosal congestion, edema, erosion or atrophy). 5.Voluntary participation and signing of informed consent form.