When you visit a gastroenterologist, they'll try to figure out your issues using hydrogen breath testing. If your body can't digest a particular compound, like lactose or fructose, the food sits in your gut allowing bacteria to gnaw away at it, producing excess hydrogen. In a breath test, you're asked to exhale into a bag, from which the doctor takes a sample and injects it into a machine about the size of a toaster oven. Then you'll have to do it again 15 minutes later. And again. And again, until the hydrogen levels spike, or the doctor is satisfied that there isn't going to be a reaction. It's highly accurate but also time consuming.

The AIRE shrinks down that analysis tech into a wafer smaller than a credit card. It has a small mouthpiece on one end. Simply put it to your lips, take a deep breath and blow. The connected app then reports your readings.

To get the most useful information from the device, you need to replicate the basic test you'd be given in a doctor's office. That involves taking a baseline reading after fasting for a period of time (first thing in the morning before you eat anything usually works). Then, you take one of the chemical packets included with the AIRE and mix the powdery contents with water. Each contains a substance like fructose or lactose -- use only the one you want to test for. After drinking the mixture, wait 15 minutes and do the test again. Repeat the breath test every 15 minutes or so, until the app reports a hydrogen spike, or you're done digesting. This can take up to three hours, though for most it's only about 90 minutes.

After using up all the packets -- which should be done on different days, in order to test the effects of each in isolation -- you'll have a pretty good idea of which substances you can't digest. And thus, a better idea of what foods you can and can't eat.