Ulcerative colitis (UC) is a chronic, inflammatory, autoimmune disease that tends to recur and increases the risk of colorectal cancer. The clinical symptoms of UC, which include diarrhea, fever, abdominal pain, cramping, bloody stool, reduced appetite, and weight loss, significantly reduce in quality of life and social functioning of patients. The incidence of UC is high in Europe and North America, especially among males, and has been on the rise in Asian countries in the past decade. In Taiwan, the prevalence rate of UC has increased more than six-fold in the past 20 years. In the project titled “An animal testing platform for maintaining intestinal health,“ supported by Taichung District Agricultural Research and Extension Station, the Ministry of Agriculture, Professor Hui-Chen Lo from the Department of Nutritional Sciences used a chemical agent to successfully induce UC in mice. The mice were orally administered with ethanol extracts of rice bran or whole-grain adlay seeds for 21 days and induced UC relapse three days before the end of the experiment. The results demonstrated that ethanol extracts of rice bran and whole-grain adlay seeds significantly alleviated inflammation, oxidative stress, and colon damage, while also improved diarrhea during UC relapse. This study may contribute to the development of rice bran, a byproduct of rice milling, and whole-grain adlay seeds as nutraceuticals to help manage ulcerative colitis.