Spit. We don’t think about it much — or I don’t, at least — but it turns out to be incredibly helpful stuff, according to the salivary researchers at the Johns Hopkins School of Nursing.

Think of it this way:  what if instead of collecting your blood, your doctor just had to collect a mouthful of saliva? (Needle-phobes everywhere breathe a sigh of relief.) For one, the researchers found that spit can be used to measure CRP, a standard way to test for cardiovascular problems. This might lead to a convenient home test — no needles! no blood! no hospitals! — to check for cardiovascular risks.

Spit can also be used to measure stress by looking at certain enzymes in saliva — something other researchers are using to measure stress in mothers-to-be. When the body feels psychological distress, the heart pounds faster, adrenaline surges, and — who knew?! — the salivary gland gets stimulated. And since plenty of other research has shown that women’s emotional state during pregnancy effects the development of the fetus, it’s helpful for doctors to be able to measure just how stressed these pregnant women are, as well as how those stress levels are evolving throughout the pregnancy. Thank god for spit.

A slice of citrus in water can do a lot more than add flavor. Recent research from Johns Hopkins University shows that a splash of lime juice and some time in the sun can help disinfect water to a certain extent — a simple, fast method that should help some of the billion-plus people planet-wide who lack access to safe drinking water.

“Previous studies estimate that, globally, half of all hospital beds are occupied by people suffering from a water-related illness,” says Kellogg Schwabb, professor of environmental health science at Hopkins and director of the Global Water Program. In many regions, a last-ditch disinfection method is solar water disinfection, in which you fill a plastic bottle with water and let it sit in the sun for at least six hours — or as many as 48 hours, if it’s cloudy. But the Hopkins researchers found that adding as little as 30 milliliters of lime juice per 2 liters of water sped the process up, lowering levels of E. coli and MS2 bacteriophage in as little as half an hour.

There are some caveats — the lime juice doesn’t reduce levels of noroviruses, and citrus isn’t readily available in some cultures. But in areas where citrus is plentiful, a little citrus goes a long way to making drinking water safe.