Scientists are hoping to compare surfer samples with regular people to see if there's any noticeable differences with their intestinal bacteria. This means that anybody can participate in the project (even if you're not a surfer).
The bad news? Since the project is U.K. based, you'd have to live in England, Wales, or Northern Ireland. Unfortunately, you can't be a newb surfer either. You'd have to surf (or bodyboard) at least three times a month.
If you're interested in participating you can email firstname.lastname@example.org.