ScienceDaily (June 3, 2009) — Researchers at Penn State College of Medicine, working with biochemists, geneticists and clinicians at the University of Bern, Switzerland and in the United Kingdom, have discovered an enzyme that has a key role in inflammatory bowel disease.....
When I read an article like this it makes me think. Growing up, I had a very strong negative reaction (I would get nausea and vomit) any time I ate pineapple. This was distinct, but I also have a dislike for melons, even though when I was really young I apparently did eat watermelon. But it made me google it and come across Bromelain,found in pineapples, from wikipedia:
"Bromelain extract is a mixture of sulfur-containing protein-digesting enzymes—called proteolytic enzymes or proteases—and several other substances in smaller quantities."
So I'll be doing some more reading.