Gulp: Adventures on the Alimentary Canal by Mary Roach

Mary Roach, author of Packing for Mars and other lively books about science, has done it again. This time, with Gulp, Roach turns her boundless curiosity on the subject of digestion.

While investigating the topic, Roach hung out with the kind of people who throw a Gut Microflora Party. She spoke to law enforcement officers and prison inmates about rectal means of transportation. ("Well over a thousand pounds of tobacco and hundreds of cell phones are rectally smuggled into California state prisons each year.") Roach tracked down historical accounts (and debunkings) of people who survived being swallowed by whales. She checked out a nutritional extract made from seabird guano. (Instructions are given to use it sparingly, or it "will be as repugnant as pepper or vinegar.") Want to know the world's riskiest menu items? Gulp is full of interesting stuff like that.

Best of all is Roach's zany wit. "On the African veldt, fats, sugar and salt were not easy to come by. That, in a nutshell, explains the widespread popularity of junk food. And wide spreads in general."

If you find the cover image unpleasantly gross, you might find the contents even more so. But come on!  Learning more about what's inside our bodies is fascinating, especially with Roach as a tour guide.