This is a pilot trial to evaluate the feasibility of conducting a large randomized trial and estimate the effects of ginger extract on the gut microbiome. This pilot study will recruit 20 subjects aged 50-75 years old who were diagnosed with colorectal adenoma in the University of Minnesota Medical Center (UMMC-Fairview) within the last five years. The subjects will receive 2000 mg of ginger extract per day (1000 mg twice a day).