Contribution of Carbohydrates and Polyphenols to Dried Plum’s Prebiotic Activity (P20-029-19)

Abstract

ObjectivesIn addition to bone protective effects, dried plums (DP) also prevent weight gain in animal models of ovarian hormone deficiency. The aim of this project was to investigate the contribution of the polyphenol (PP) and carbohydrate (CHO) components of DP on weight gain and body composition, as well as their effects on the gut environment. MethodsTwo studies were performed using 8-wk-old C57BL/6 female mice that were sham-operated (Sham) or ovariectomized (Ovx), and allowed to lose bone prior to treatment for 5 or 10 wks. In Study 1, Sham and Ovx mice were assigned to control (AIN-93 M), control diet with added DP (25% w/w) or a crude PP extract (CPE; equivalent PP to DP). In Study 2, Ovx mice were randomized to diets with the CPE fractions, PP or CHO, in a 2x2 factorial design. At the end of each study, bone mineral density (BMD) and body composition were assessed. Cecal bacterial taxa and short chain fatty acids (SCFA) were characterized at 5 and 10 wks, respectively. Non-microbiome data were analyzed using 1-way or 2-way ANOVA (SAS, Version 9.4). ResultsIn Study 1, Ovx increased (P < 0.01) weight gain, %fat and abdominal white adipose tissue (WAT), and DP and CPE mitigated (P < 0.05) this response at 5 and 10 wks. Likewise, DP and CPE reversed the Ovx-induced decrease in BMD at both time points. DP and CPE enriched the SCFA-producing family, Lachnospiraceae, as well as Coriobacteriaceae and Verrucomicrobiaceae, which are associated with weight regulation. Cecal acetic, propionic, n-butyric and n-valeric acids were increased by DP and CPE compared to Ovx-control, but the response was greater with DP. In Study 2, CHO with or without PP, reduced Ovx-induced weight gain (P < 0.01), %fat (P < 0.001), WAT (P < 0.01) and reversed the loss of BMD at both time points. Compared to CPE, Verrucomicrobiaceae was more abundant with the PP group, but there was no change in β diversity with the CHO group. All of the assessed SCFA were increased with CHO, regardless of PP content, while n-butyric acid and the two isomers of valeric acid were independently enhanced by PP. Among the assessed outcomes, there were no additive effects of CHO and PP. ConclusionsAlthough their prebiotic effects differ, both the CHO and PP components contribute to DP’s effects on weight gain and body composition. Funding SourcesOCAST; California Dried Plum Board.