Everything You Never Wanted To Know About Digestion

by Patrick Appel

Bee Wilson enjoyed Mary Roach’s new book, Gulp:

If you’ve ever wondered why some people complain of gassiness after beans, while others eat them with impunity, Roach has the answer. If you’ve never wondered, too bad; Roach is going to tell you anyway. Apparently, half of the population lack a certain enzyme in the colon that is needed to break down the complex carbohydrates in legumes. As a result, they are “troubled by beans.” When the colon inflates, releasing gas, it is a “warning system”: “Because stretching can be a prelude to bursting, your brain is highly motivated to let you know what’s happening down there.”

In an interview about her book, Roach sings the praises of saliva:

[I]n saliva there’s these histatins which help wounds heal. So when someone kisses a baby’s booboo, like a scrape, or when a pet licks its wounds, it’s actually – because you think oh, oh, it’s full of bacteria, don’t do that. But there’s these healing elements. Saliva was a home remedy for cuts and scrapes and shankers and things. People would apply the spittle of a – first-thing-in-the-morning spittle of an old man or something would be, like, the remedy. But there’s some medical sense to it.