Faba beans are among the legumes that are of the greatest importance due to their high nutritional value. In addition to the essential nutrients that faba beans contain, they also contain bioactive compounds such as phenolics and flavonoids that are considered as potent natural antioxidants. Ulcerative colitis (UC) is an inflammatory bowel disease in which oxidative stress plays an essential role in the pathophysiology. The aim of the current study was to evaluate the antioxidant activity of faba bean seeds harvested from plants grown from seeds pre-treated with selenium, garlic husk extract and/or lemon peel extract and to evaluate their in vivo effects in a rat model of UC. 54 female rats were divided randomly into nine groups (n = 9). All groups were given the different tested treatments 14 days prior to UC induction using acetic acid (intra-rectal injection of 2 ml, 4% v/v in saline). Our results revealed that the treatment of faba bean seeds with a mixture of selenium, garlic husk extract and lemon peel extract before planting led to a significant increase in selenium, nitrogen, potassium, total protein, phenolic and flavonoid content in the harvested faba bean seeds with a subsequent enhancement of their antioxidant capacity. Consumption of such faba beans showed potential protective and therapeutic effects during experimental colitis by reducing colonic oxidative stress and increasing colonic antioxidant defense mechanisms. Further research is required to understand the mechanisms by which faba beans influence colitis, their effects on various inflammatory biomarkers and their impact on the severity of colitis in humans.