If you've ever had food poisoning, you know that the offending food is generally more than ready to escape back out of your stomach. But a new study shows that sometimes food makes us sick because it just won't let go of our gut.
Many instances of food poisoning happen when bacteria that ride in on contaminated food trigger a feverish immune response. In the case of beans and grains, however, simply being undercooked can cause nausea and vomiting. But why? A team led by cell biologist Paul McNeil of the Medical College of Georgia, have discovered the reason: Certain vegetable proteins are the culprit.
The proteins, called lectins, can bind tightly to certain spots on our gut cells. This, the researchers found, prevents the cells from repairing themselves after an injury -- an important process for gut cells, because they're exposed to all manner of food particles in the harsh stomach environment and need constantly to send out new pieces of cell membrane or extra layers of mucus.
In the presence of the lectins, the gut cells fail on both accounts. The researchers were even able to record movies of the failure after injuring dishes of mouse gut cells with lasers or a "sharp implement," as the study paper put it. When there were lectins around, the cells became pocked and leaky, allowing fluorescent dyes to seep into them.
Once the body senses that the gut cells can't repair themselves and are dying, it decides to jettison the whole noxious load -- in other words, to vomit. In a press release, McNeil points out that alcohol causes this same type of cell damage and response.
The study appears in the Aug. 1 issue of the journal PloS One, and was funded by NASA -- which may seem weird till you realize that gravity-free astronauts want to know all they can about how to keep their food down.
Read the whole article for free at the Public Library of Science:
Or simply watch the movies! (You'll find them in the "supporting information" link.)
-- Chelsea Martinez