Efficacy of actinidin-containing kiwifruit extract Zyactinase on constipation: a randomised double-blinded placebo-controlled clinical trial.

BACKGROUND AND OBJECTIVES: Zyactinase® is an extract of green kiwifruit, formulated into the consumer healthcare products marketed as Phloe® and Kivia, used to assist in the relief of the symptoms associated with a range of digestive system dysfunction, including constipation and Irritable Bowel Syndrome (IBS).

METHODS AND STUDY DESIGN: A randomised, double-blind, placebo-controlled clinical trial was undertaken to determine the ef-fects of the kiwifruit extract on bowel movement, stool formation and IBS associated symptoms amongst a sub-ject group of generally healthy individuals experiencing a period of moderate constipation. Fifty-eight partici-pants were randomized to the kiwifruit extract (28) or placebo (30). Selection criterion was decreased number of bowel movements (<3/week), with increased faecal hardness and IBS associated symptoms. The study ran for three weeks, with participants first undergoing a seven-day wash out period, followed by a seven-day dosing pe-riod, and then a seven-day follow up period.

RESULTS: There was a significant increase in the defecation frequency (p<0.001), with a significant improvement in faecal score (p<0.01). There was a significant difference in pain-ful defecation and abdominal pain between the two groups (p<0.01). No side effects, including diarrhoea, urgen-cy or abdominal pain, were observed during the trial.

CONCLUSIONS: The green kiwifruit extract significantly in-duced normal bowel movements with no adverse effects. The kiwifruit extract relieved constipation and the symptoms of IBS such as bloating, flatulence and abdominal pain.