ObjectivesTo investigate the efficacy and safety of Hou Gu Mi Xi (HGMX) in patients with nonorganic gastrointestinal disorders (NOGD) from the aspect of dietary therapy.MethodsA randomized, double-blind, parallel, placebo-controlled trial was performed. Patients with NOGD and spleen qi deficiency (SQD) syndrome were randomly assigned into HGMX or placebo group. Each received 30 g/day HGMX or placebo for one year. The outcomes included SQD scores, body weight, body mass index (BMI), gastrin-17, and adverse events (AEs) between HGMX and placebo groups, or subgroups divided by NOGD type or helicobacter pylori (Hp) infection, at the 0th, 2nd, 4th, 8th, 26th, or 52nd weeks’ follow-up.ResultsThe reduction of SQD scale score was found in the HGMX group compared with the placebo group at 4th week (MD=−9.40, 95%CI −18.53 to −0.27, P=0.044), 8th week (MD=−10.07, 95%CI −19.66 to −0.48, P=0.04), 26th week (MD=−12.45, 95%CI −22.31 to −2.59, P=0.014) and 52th week (MD=−17.25, 95%CI −28.53 to −5.97, P=0.003), respectively. In the subgroup analyses, HGMX showed significant efficacy in Hp-negative patients with the detailed reduction of SQD scale score being (MD=−15.20, 95%CI −28.16 to −2.24, P=0.022), (MD=−17.91, 95%CI −31.22 to −4.59, P=0.009) and (MD=−20.38, 95%CI −35.43 to −5.32, P=0.008) at the 8th, 26th and 52nd week, respectively, and in patients with chronic nonatrophic gastritis with the detailed reduction being (MD=−13.02, 95%CI −24.75 to −1.29, P=0.03), (MD=−12.43, 95%CI −24.36 to −0.5, P=0.041) and (MD=−15.90, 95%CI −30.72 to −1.08, P=0.036) at the 2nd, 26th and 52nd week, respectively, and in patients with functional gastrointestinal disease with the reduction being (MD=−18.22, 95%CI −35.75 to −0.69, P=0.042) at the 52nd week. However, no significant efficacy was found in Hp-positive patient at any time. HGMX was not associated with changes in weight, BMI, or gastrin-17. No AEs were reported in the HGMX group.ConclusionsHGMX improves SQD symptoms in patients with NOGD, especially Hp-negative patients, and has a good safety profile.