Main idea: The study has demonstrated that consuming the skin of SunGold kiwifruit might have beneficial effects on gastrointestinal health that are not produced by consuming the flesh alone.
Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that results in constipation (IBS-C) or diarrhea with abdominal pain, flatulence, nausea, and bloating. Kiwifruit (Actinidia spp.) is a nutrient-dense fruit with a number of reported health benefits that include lowering glycemic response, improving cardiovascular and inflammatory biomarkers, and enhancing gut comfort and laxation. This study investigated the effect of consuming three whole Zespri® SunGold kiwifruit (Actinidia chinensis var. chinensis ‘Zesy002’) with or without skin on cytokine production and immune and gut health in healthy people and those with IBS-C symptoms. This study enrolled thirty-eight participants in a 16-week randomized cross-over study (19 healthy and 19 participants with IBS-C). Participants were randomized to consume either three kiwifruits without eating the skin or three kiwifruits including the skin for 4 weeks each, with a 4-week pause in between each intervention. There was a significant decrease in the pro-inflammatory markers (cytokine, TNF-α) for both the healthy and the IBS-C participants when they consumed the whole kiwifruit and skin, and also for the healthy participants when they ate whole kiwifruit without the skin (p < 0.001). The kiwifruit interventions increased bowel frequency and significantly reduced the gastrointestinal symptom rating scale constipation and Birmingham IBS pain scores for both participant groups.