(P03-090-23) Oat β-Glucan Had Dose-Effect on Glucose Tolerance, Body Weight and Fat Depots in Rats Fed Moderately High Fat Diets

Objectives: To explore the dose-effect of dietary oat β-glucan on fasting glucose, glucose tolerance, body weight, liver and fat depots in rats during high fat feeding.

Methods: Fifty male Wistar rats were randomly assigned into five groups and were fed the following diets for 5 weeks: low fat (LF), high fat (HF), high fat + low dose oat β-glucan (LBG), high fat + medium dose oat β-glucan (MBG), high fat + high dose oat β-glucan (HBG). Body weight (BW) and food intake were measured once a week. Fasting blood glucose and oral glucose tolerance were assessed after 24 days’ experimental feeding. By the end, the animals were sacrificed, liver and adipose tissues were harvested and weighted. Organ index and correlations were calculated. The data were analyzed by one way analysis of variance and posthoc tests using SPSS. A p -value less than 0.05 is statistically significant.

Results: After 2 weeks' experimental feeding, BW and feeding efficiency for the HBG group were significantly lower compared with the LF, HF and LBG groups. The dose-effect of oat β-glucan on BW continued toward the end of the experiment. After 3.5 weeks, the MBG and HBG groups had lower fasting glucose level compared with the HF group. The LBG, MBG, and HBG groups had significantly smaller absolute area under the curve during the oral glucose tolerance test compared with the HF group. After the oral glucose challenge, the fasting glucose in the HBG group had the slowest increasing rate but also tended to have a slower rate returning back compared with the MBG group. After 5 weeks, the HBG group had significantly less amount of epididymal fat compared with the LBG and MBG groups. The HBG group also had less inguinal, visceral and total separable fat depots compared with the LBG group. The HBG group had smaller liver index compared with the HF group. The liver index was strongly correlated with the visceral fat index (r=0.72, p< 0.0001).

Conclusions: Dietary oat β-glucan had dose-effect on glucose tolerance, body weight and epididymal fat. The high dose oat β-glucan supplementation significantly reduced both subcutaneous and visceral fat depots compared with the low dose group. The beneficial effects of oat β-glucan should be further explored in consideration of dose-effect.

Funding Sources: The project was funded by a Research Initiation Grant at Guangxi University of Chinese Medicine (2018BS068).