This randomised, cross-over study investigated the impact of ACTAZIN green and Livaux™ gold kiwifruit supplements on faecal microbial composition and metabolites in healthy and functionally constipated (FC) participants.
Both products are marketed by New Zealand firm Anagenix.
The intervention combinations included placebo, ACTAZIN L (600 mg/d), ACTAZIN H (2400 mg/d) and Livaux (2400 mg/d) for 28 days, with a washout period between each treatment phase.
The most notable finding was that in the FC group, Faecalibacterium prausnitzii abundance significantly increased from 3.4% to 7.0 % following Livaux supplementation, with eight of the nine participants showing a net increase.
Low amounts of F. prausnitzii have been associated with a range of intestinal disorders, including irritable bowel syndrome (IBS), atopy, diabetes and inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis.
Anti-inflammatory effects
The study, published in the Journal of Nutritional Science and led by scientists from Plant and Food Research, stated: "Lower proportions of F. prausnitzii are often associated with gastrointestinal disorders. The discovery that Livaux supplementation increased F. prausnitzii abundance offers a potential strategy for improving gut microbiota composition, as F. prausnitzii is a butyrate producer and has also been shown to exert anti-inflammatory effects in many studies."
Butyrate is the preferred energy source for colonic epithelial cells and plays a role in alleviating inflammation, as well as mitigating carcinogenesis, pathogenic colonisation and oxidative stress.
"Other results arising frothis trial, assessing laxation endpoints, were published separately and showed that the kiwifruit supplements were able to significantly increase bowel movements in healthy individuals," the researchers added.
They pointed out that green and gold kiwifruit had been shown to exhibit differences in digestibility, leading to altered soluble and insoluble fibre compositions reaching the large bowel and potentially explaining the differences observed in this study.
International interest
Anagenix MD Chris Johnson told us the Livaux product was already receiving interest from manufacturers in the US, China, Korea and Thailand.
"We think this is a great product because 30% of people are functionally constipated," he said.
"Gold kiwifruit was previously considered not as helpful to gut health as green kiwifruit, which has larger amounts of dietary fibre and the enzyme actinidin. However, this research shows that Livaux is a highly effective and novel prebiotic."
The paper concluded: "Livaux appears to stimulate proliferation of the commensal F. prausnitzii in participants with low initial F. prausnitzii concentrations, and this may be associated with higher in situ butyrate concentrations, although this is difficult to measure in a human study.
"These results bear clinical relevance, as stimulating an increase in an abundant butyrogenic bacterium could have beneficial consequences for ulcerative colitis patients. Future work to corroborate these results could entail in vitro studies to measure butyrate production and F. prausnitzii stimulation in a closed system."
Source: Journal of Nutritional Science
Journal of Nutritional Science (2017), vol. 6, e52
"Consumption of kiwifruit capsules increases Faecalibacterium prausnitzii abundance in functionally constipated individuals: a randomised controlled human trial"
Authors: Paul Blatchford, et al.