You're better off drinking out of your dog's water bowl!
girl drinking from water bottle
Credit: Rebecca Nelson/Getty Images

This news won't be easy to swallow.

USA Today recently reported on the results of an analysis by EmLab P&K, an environmental testing firm, that found that the insides of an average reusable water bottle, left unwashed, contain more than 300,000 colony-forming units of bacteria per square centimeter.

According to the study, which was conducted for the site, that's roughly six times the amount of bacteria found on pet bowls, and just slightly less than your bathroom toothbrush holder. Gulp.

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For the study, researchers swabbed a dozen athlete's water bottles that hadn't been cleaned in a week. They also compared different types of bottles: Three squeeze top, three slide top, three screw top and three straw top. They found that slide-top bottles, with 933,000 colony-forming units of bacteria per square centimeter, were the absolute grossest, while straw-bottles carried just 25.4 units per square centimeter.

Grossed out? You should be! Experts recommend using stainless steel bottles, which are naturally anti-bacterial and resistant to germ-harboring cracks. But if you're committed to your trusty old bottle, the best way to combat germs is by washing it with warm water and soap after every use. Or, if it's dishwasher safe, pop it in there with your dishes.