Poster Topical Area: Nutritional Microbiology
Poster Board Number: 252
Objectives: To test if cranberry components would improve the gut microenvironment by modulating gut microflora activity in an in vitro fecal fermentation condition.
Methods: The effect of cranberry extract was tested at 0.5 millimolar (mM) and 1 mM for 24 and 48 hours. All test ingredients were added to the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®). A 2% inoculum of an adhesive invasive Escherichia coli (AIEC) culture was also added to the incubation. The effect of the test product was evaluated for up to 48 hours at 37 degree Celsius under shaking and anaerobic condition. AIEC colonization was assessed by selective enumeration for both the luminal and mucosal compartments. Changes in the degree of acidification, short chain fatty acids (SCFA), branched SCFA and lactate production were quantified. Differences between treatment at each concentration and time point were assessed by two-way ANOVA.
Results: Cranberry extract at a concentration of 1 mM suppressed the adhesive capability of AIEC by 0.44 Log CFU/mL after incubation for 48 hours (P = 0.085). Compared to a negative control, cranberry extract reduced the pH from 6.57 to 6.27 units following 24-hour incubation at a concentration of 0.5 mM (P = 0.009). The higher concentration of 1 mM further decreased the pH by 0.23 units to 6.04 (P = 0.046). After incubation of 48 hours, pH changes induced by cranberry extract remained stable. Total SCFA was significantly increased by 25% following incubation with 1 mM cranberry extract for 48 hours (P = 0.045), with the predominant differences detected in the first 24 hours. Among individually tested SCFA, acetate and propionate were significantly elevated following incubation for 24 hours and increased further by 48 hours. However, changes in butyrate or branched SCFA were not different from control at either time point. Lactate production tended to be higher during the first 24-hour incubation period, suggesting a stimulation of lactic acid producing bacteria.
Conclusions: Cranberry extract might limit the ability of pathogenic AIEC to grow and adhere in the colonic environment. Cranberries have the potential to modulate microflora activities as demonstrated by the generation of more SCFA and lactate.
Ocean Spray Cranberries, Inc.