Effects of Oat Beta‐Glucan and Exercise Training on Tumor Burden in APC‐Min Mice

Abstract

Both oat beta‐glucan (OBG) and exercise training (EXT) can enhance macrophage function. We hypothesized that EXT and OBG would reduce intestinal polyp burden in APC‐Min mice by reducing macrophage‐mediated inflammation and that the combination of the two treatments would have an added beneficial effect. Eighty male APC‐Min mice were randomly assigned to the following treatment groups at 4 wks of age: EXT, OBG, EXT and OBG, and control (CON). EXT mice ran on a treadmill (18–22 m/min, 60 min/d, 6 d/wk, 11 wks). OBG mice received 6 mg/ml of the soluble fiber in their drinking water daily. At 15 wks of age, mice were sacrificed and tissues collected. Polyps were counted based on size, crypt‐to‐villi (CV) ratios were measured, and macrophages in polyps and lamina propria were determined immunohistochemically. Statistical analysis was done using ANOVA and Tukey post‐hoc analysis. Compared with CON, there was a significant reduction in polyp size, polyp number, CV ratios, and macrophage numbers in the EXT and OBG groups. However, the combination of EXT and OBG resulted in a significant increase in deaths, polyp size, polyp number, and CV ratios compared with CON. Therefore, both OBG and EXT were beneficial in this mouse model, in part, through reduced macrophage tumor infiltration and inflammation. However, their combination was detrimental through an as‐yet‐undetermined mechanism.