It has been found that reusable water bottles can harbor 40,000 times more bacteria than the average toilet seat, according to a study by waterfilterguru.com.
Researchers detected two types of bacteria present: Gram-negative rods and bacillus, after swabbing various water bottle sections three times each, including the spout lid, straw lid, and squeeze-top lid.
Infections caused by Gram-negative bacteria are resistant to antibiotics, while certain types of bacillus can cause gastrointestinal problems.
Compared to household objects, the bottles were twice as dirty as a kitchen sink, four times as dirty as a computer mouse, and 14 times dirtier than a pet’s bowl.
“The human mouth is home to a large number and range of different bacteria,” said Dr. Andrew Edwards, a molecular microbiologist at Imperial College London.
“So it’s not surprising that drinking vessels are covered in microbes.”
Clarke said that while bottles can serve as breeding grounds for bacteria, they are not necessarily dangerous.
“I’ve never heard of someone getting sick from a water bottle. Similarly, taps are clearly not a problem: when did you last hear of someone getting ill from pouring a glass of water from a tap? Water bottles are likely to be contaminated with bacteria already in people’s mouths.”
As a result of the tests, squeeze-top bottles were found to be the cleanest, with a tenth of the amount of bacteria found in screw-top or straw-style bottles.