The Future of Cancer Prevention-Part II. In 2018, colorectal cancer was the third-most common diagnosed cancer among both men and women in the U.S., and data indicate that younger adults are increasingly being diagnosed with it. A new research initiative will examine how the microbiome—a collection of trillions of microorganisms throughout the body—affects the development of colorectal cancer. In part two of our miniseries on cancer prevention, we’re speaking with one of the co-principal investigators of the team, Wendy Garrett, professor of immunology and infectious diseases at Harvard T.H. Chan School of Public Health.