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Resumen del póster presentado a la 7th International Conference on Polyphenols and Health, celebrada en Tours (Francia) del 27 al 30 de octubre de 2015., The beneficial effects of cranbeny products against urinary tract infections (UTIs) have been attributed, at least partly, to their A-type proanthocyanidin (PAC) content. A-type PACs have shown uropathogenic Escherichia coli (UPEC)-anti-adhesive activity, although they are unlikely to appear in urine at relevant concentrations as they are poorly absorbed. One leading hypothesis is that PAC-derived metabolites present in urine would operate in the phase of UPEC adyherence to uroepithelial cells, preventing bacterial colonization. In addition to this, and as it is becoming evident that the intestine is a reservoir for uropathogenic bacteria, other hypothesis is that. A-type proanthocyanidins specifically decrease the transient intestinal colonisation b UPEC, consequently reducing the risk of UTI incidence. In any case, gut microbiota (and its inter-individual variability) seems to be an important factor to be considered. In this communication, we summarize our results from different approaches aimed to look into the mechanisms that are behind the protedive action of cranberry polyphenols against ITUs: 1)in vitro fermentations of cranbeny polyphenols with colonic microbiota, that were performed to access the microbial-derived metabolic profile of cranbeny polyphenols as well as their effect on gut microbiota survival, 2) an in vivo trial with model mouse intraurethral-inoculated wilh UPEC, that evaluated the effectiveness of cranbeny supplementation in bacterial infection as well as its impact on faecal phenolic metabolism and faecal microbiota, 3) testing the UPEC-antiadhesive capacity of cranbeny phenolic compounds and their metabolites in bladder epithelial cell culíures, and 4) ex vivo studies of UPEC-antiadhesive capacity of mice mines collected after cranbeny supplementation., Ministry of Economy and Competitiveness (MiNECO) (Projects AGL-2010-17499 and AGL2012-40172-C02-01) and the Comunidad Autónoma de Madrid (Project ALIBIRD S2013/ABI-2728), Spain.

Resumen del póster presentado a la VI International Conference on Polyphenols and Health celebrada en Buenos Aires (Argentina) del 16 al 19 de octubre de 2013., Proanthocyanidin structure features (i.e, interflavanic bond A- or B-type) seems to influence their biological activity. Among others, A-type proanthocyanidins have proven to inhibit the adhesion of pathogenic bacteria to uroepithelial cells of the urinary tract, a property not found for B-type proanthocyanidins. Scientific evidence indicates that the physiological effects of proanthocyanidins could be due to the metabolites formed in the tissues and, mainly, by the colon microbiota during their passage through the gastrointestinal tract. On the other hand, proanthocyanidins and/or their microbial-derived metabolites could exert a selective effect on inhibition or stimulation on the intestinal microbiota that, in turn, would affect microbial metabolizing capacity. The aim of this study was to explore differences in colonic catabolism between A- and B-type proanthocyanidins, by means of experiments in mice fed with cranberry (rich in type-A proanthocyanidins) and grape seed (rich in type-A proanthocyanidins) extracts. After a 3-week adaptation time, JAXc3H/OuJ female mice (n=30) were divided into three groups and maintained in a specific diet (control, 1% cranberry extract and 1% grape seed extract) for 4 weeks. Faecal samples were collected at 5 different times and analysing for phenolic metabolites by UPLC-ESI-MS/MS and for microbial counting of Lactobacillus, Bifidobacterium, Enterobacteria, Clostridiumgroups and Escherichiacoli species. Results indicated differences in the metabolism of A-type and B-type proanthocyanidins related to changes in some microbial groups.

Resumen del póster presentado a la VI International Conference on Polyphenols and Health celebrada en Buenos Aires (Argentina) del 16 al 19 de octubre de 2013., Consumption of cranberry (Vaccinium macrocarpum) is widely recommended forprophylaxis against urinary tract infections (UTI) in women. Among cranberry components, A-type proanthocyanins would be implicated in these preventive effects against UTI. However, proanthocyanidins are poorly absorbed in the small intestine, but subjected to extensive biotransformation in the colon, although studies are almost restricted to B-type proanthocyanidins. Therefore, the hypothesis of this study is that urinary metabolome from of A-type and B-type proanthocyanidins-mainly derived from their colonic catabolism-differ,and only metabolites from the A-type procyanidins have protective effects against UTI. To test this hypothesis, JAXc3H/OuJ female mice previously fed with specific diet (control, 1% cranberry extract and 1% grape seed extract) for 2 weeks, were inoculated with the uropathogenic E. coli (ATCC 53503™) to provoke infection, and maintained 2 weeks more before being sacrificed. Urine samples were collected at different times and subjected to E.coli counting, leukocytary esterase and nitrites analyses, and mieloperoxidase task. Samples of kidney and bladder tissues were also collected for E. coli counting and histopathologic analysis. Additionally, the capacity of the urine samples to inhibit bacterial adherence was tested in the T24 bladder cell line (ATCC HTB4 ™).