Kiwifruit for constipation and gastrointestinal comfort: mechanisms, clinical evidence, and remaining research gaps

Abstract Background and Aim Kiwifruit has been investigated as a whole-food intervention for functional constipation (FC), constipation-predominant irritable bowel syndrome (IBS-C), and gastrointestinal (GI) discomfort. However, previous reviews have not fully integrated recent clinical trials with contemporary fibre terminology and cultivar-specific mechanisms. This narrative review aimed to clarify the clinical evidence, plausible mechanisms, effective regimens, and remaining research gaps for kiwifruit as a dietary strategy for FC and IBS-C and their constipation-related symptoms. Methods PubMed and Web of Science were searched for English-language publications from January 1984 to June 2026. Earlier evidence was defined as publications up to December 2017, and recent evidence was defined as publications from January 2018 onward. Thirty-three publications were included in the narrative synthesis. Results The strongest evidence supports the use of two fresh green kiwifruits daily for approximately 4 weeks in adults with FC, IBS-C, or chronic constipation. Clinical studies report increases in complete spontaneous bowel movements, improved stool form, reduced straining, and better GI comfort, with generally favourable tolerability. Mechanistically, green kiwifruit combines bulking, fermentable, and gel-forming fibre properties with intrinsic water, sorbitol, polyphenols, microbiota-active substrates, micronutrients, and actinidin. Conclusions Kiwifruit is best positioned as an evidence-based, low-burden dietary option within individualised constipation care, rather than as a universal substitute for laxatives or dietitian-led IBS management. Further trials should define cultivar-specific effects, long-term adherence, clinically meaningful effect sizes, and comparative effectiveness.