Metabolic Health and Kiwifruit
Dr. Paul Blatchford
The New Zealand Institute for Plant & Food Research, New Zealand
The research presented attempts to understand how kiwifruit impacts upon microbial composition and metabolism in the human large bowel using in vitro fermentation systems. Kiwifruit contains non-digestible polysaccharides (2-3%) as well as other compounds including polyphenols, fatty and organic acids, proteins, vitamins and minerals that may alter microbial ecology in the large bowel. Given the evidence supporting the link between colonic microbiota function and disease, any mechanism that is able to alter the microbiota bears relevance for human health.
It is for this reason that potentially prebiotic molecules are being extensively studied and tailored to attempt to beneficially alter colonic microbiota composition. The methods used in this research were in vitro pH-controlled anaerobic batch fermenters in conjunction with 16S rRNA gene sequencing and metabolomics platforms. We found that green-fleshed Actinidia deliciosa (‘Hayward’) and gold-fleshed Actinidia chinensis (‘Zesy002’) kiwifruit fermentation promoted a microbiota that was significantly enriched in Bacteroides spp., Parabacteroides spp. and Bifidobacterium spp. These commensal genera are positively correlated with human health through various mechanisms including fortifying intestinal barrier integrity, producing antibacterial compounds and modulating the immune system. The kiwifruit-driven increase of commensal bacteria in the in vitro models resulted in a propionate-enriched environment. Propionate, which generally travels to the liver via portal circulation, is involved in gluconeogenesis and has been shown to play a role in regulating cholesterol synthesis. This work also showed that the kiwifruit organic acids, malic acid, quinic acid and citric acid are able to resist simulated digestion and reach the colon intact, potentially altering bacterial composition therein. The results achieved in this project contribute towards understanding how kiwifruit benefits human health via an improved microbial community composition and metabolic profile.
View presentation Kiwifruit-driven Microbiota, Metabolites And Implications for Human Health by Dr Paul Blatchford from Kiwifruit Symposium