A LiveScience study says probably not. On the water side of the equation, the U.S. Geological Survey estimates that Earth has about 1.4 billion gigatons of water, including that in oceans, ice caps, glaciers, lakes, rivers, groundwater and vapor.

Maybe you have ordered an at-home microbiome test and waited on a report full of unfamiliar bacteria names. Maybe you are just watching friends compare their results. Either way, the gut has become something people study rather than ignore. That attention raises a fair question about which foods and compounds genuinely help. The latest contender is one that nutritionists spent years telling you to limit.

Dr. Kelly Tseng a professor in the School Of Life Sciences at the University of Nevada-Las Vegas, discusses how discovering the method in which frogs are able to regenerate eye tissue could lead to finding out how to replicate the process in humans.