Bunching up on broccoli for as little as two weeks may be worth the effort.

Researchers from the University of California put undergraduate students and instructors on a two-week diet. For the first week, participants followed their typical day-to-day meal preferences. In the second week, participants tracked their nutritional intake in order to reach 40 grams of fiber per day. Researchers also provided 10 plant-based fiber-filled meals per week.

In the second week of the participants’ high-fiber diet, they increased their fiber intake to 50 grams each day. For some students, this was comparable to their diet prior to enrolling in the studies. For others, it was a leap from zero to 50.

After the two weeks of fiber boot camp, the participants’ gut microbiomes showed an 8% improvement. Most of the increase in bacteria were types known for breaking down fiber.

Although fiber is the unsung champion of human health, only about 5% people in the United States get the recommended amount. Fiber is an integral part of gut microbe health, and a plant nutrient whose absence can be associated with diseases like colorectal cancer and autoimmune disorders.

Your body’s small intestine cannot digest fiber, so microbes break it down once it travels into the colon. This process creates short-chain fatty acids, or SCFAs, that are believed to play critical roles for a range of factors affecting overall health.

Of course, two weeks is a short span of time. Consequently, researchers from the study intend to carry out longer dietary fiber interventions to better understand and document the effect of fiber in supporting gut health.