Cranberries and probiotics are individually considered as functional foods. This study evaluated the potential synergy between bioactive proanthocyanidins (c-PAC) derived from cranberries and probiotics on reducing the invasiveness of extra-intestinal pathogenic Escherichia coli (ExPEC) in a cell culture model. ExPEC can be a component of the gut microbiota in healthy individuals, and reducing the invasiveness of ExPEC is a potential means to lessen the risk of subsequent urinary tract infections (UTI), the most common bacterial infections in women. c-PAC (>92 % A-type) concentrations greater than 36 μg c-PAC/mL significantly (p<0.05) reduced ExPEC invasion, and was not inhibited by the presence of probiotics. Scanning electron microscopy suggests that the mechanism by which c-PAC prevent ExPEC invasion is by cross-linking surface virulence factors. A probiotic blend also significantly reduced invasion, albeit via a different mechanism. This study demonstrated the potential benefit of combining functional A-type c-PAC components in cranberry foods with probiotics.
Polewski, M. A., Krueger, C. G., Reed, J. D., & Leyer, G. (2016). Ability of cranberry proanthocyanidins in combination with a probiotic formulation to inhibit in vitro invasion of gut epithelial cells by extra-intestinal pathogenic E. coli. Journal of Functional Foods, 25, 123–134. https://doi.org/10.1016/j.jff.2016.05.015