This randomised double-blind placebo-controlled trial evaluated the efficacy and safety of fermented gold kiwi (FGK) in improving gastrointestinal health. A total of 100 participants were enrolled and randomly assigned to treatment or placebo groups. Over 8 weeks, the participants consumed an FGK or placebo preparation daily. Primary outcomes included changes in gastrointestinal symptoms assessed using the Gastrointestinal Symptom Rating Scale (GSRS) and the Korean version of the Nepean Dyspepsia Index (NDI-K), as well as quality of life assessed using the Functional Dyspepsia-related Quality of Life questionnaire. The FGK group showed significant improvements in GSRS and NDI-K total and subdomain scores compared with the placebo group. Moreover, the quality of life scores were significantly better in the FGK group than in the placebo group. Safety evaluations revealed no significant adverse events or clinically meaningful changes upon assessing laboratory test results. This study demonstrated that FGK is a safe and effective dietary supplement for improving gastrointestinal health in adults with gastrointestinal symptoms.