(P19-022-25) Influence of Prebiotic Cranberry Products on Fecal and Vaginal Microbiota in Healthy Women for Urinary Tract Infection Prevention: An In Vitro and In Vivo Investigation

Objectives: To assess cranberry seed and presscake in vitro influence on fecal microbiota from healthy women (n = 10) and how cranberry juice influences fecal and vaginal microbiota in healthy women (n = 47) over 45 days for urinary tract infection (UTI) prevention.

Methods: Cranberry seed, presscake, and pectin underwent oral, gastric, and intestinal digestion for in vitro fermentation on fecal samples collected from ten healthy women ( > 18 years, body mass index = 18-35 kg/m²). Measurements were taken at hour 0, 8, 24, and 32 for fecal microbial composition. In vivo, 47 healthy women participated in a randomized, double-blind, crossover, placebo-controlled dietary intervention with daily consumption of one cranberry or placebo beverage (8 fluid ounces) for 15 days each with a 15-day washout period in between. Before and after each DP, participants self-collected stool, vaginal, and urine samples for a total of four sample sets. Stool and vaginal samples (n = 188 each) as well as in vitro samples (n = 160) underwent dual indexed high throughput 16S ribosomal RNA sequencing via Illumina MiSeq. Urine samples (n = 188) will undergo liquid chromatography mass spectrometry for metabolites.

Results: Preliminary results from the in vitro fecal fermentation revealed an increase in Clostridium spp. from cranberry seeds and presscake. A bifidogenic effect also appears after fermentation for both cranberry products with an increase in Bacteroides. For the in vivo pilot study (n = 7) of the dietary intervention (n = 47), the most consistent trend observed is a reduction of Proteobacteria in the vaginal microbiota with one of the clinical beverages and an increased diversity after DPs. For the gut microbiota, a nonmetric multidimensional scaling (Bray-Curtis Index) reveals microbial modulation after DPs and a significant difference (p < 0.05, Mann-Whitney-U) between both clinical beverages for Eggerthella.

Conclusions: Preliminarily, both in vitro and in vivo studies indicate potential cranberry prebiotic effects for UTI prevention in healthy women via microbial modulation. The trends observed reveal a decrease in vaginal uropathogenic bacteria (Proteobacteria) and increase in fecal taxa (Bacteroides and Clostridium spp.) that utilize cranberry polysaccharides and polyphenols for antimicrobial effects and gut homeostasis.

Funding Sources: Northwest Center for Small Fruits Research