On a balmy summer’s day, what better way to cool down yet stay alert than with an iced caramel macchiato, right?
Well, this story may put you off your iced coffee. Researchers from the BBC have found that the ice used by three major coffee chains in the U.K.—Starbucks, Caffe Nero and Costa Coffee—contains bacteria that is found in human faeces.
Seven out of 10 samples of ice used in Costa Coffee drinks were contaminated with bacteria from human poop, while three out of 10 samples from both Starbucks and Caffe Nero also tested positive for the bacteria, according to a report from the BBC’s consumer series Watchdog.
Fecal coliforms are bacteria that form in the intestines of warm-blooded animals and are capable of growing in the harsh, acidic conditions of the digestive tract. An example of a fecal coliform is Escherichia coli (E. coli), some variations of which can cause serious food poisoning. There is no indication that the ice used by the coffee chains contains E. coli.
The researchers also tested cleanliness of tables, trays and high chairs at 30 branches of each chain.
“The level of contamination of fecal bacteria concerns me a great deal. The bacteria are opportunistic pathogens—the source of human disease. These should not be present at any level, never mind the significant numbers found,” Tony Lewis, a spokesman for the Chartered Institute of Environmental Health, according to The Telegraph.
All three coffee chains said they had taken action in light of the report. Starbucks said it was conducting an internal investigation and that it took hygiene “extremely seriously.”
“All employees nationwide have received updated training on our high standards of hygiene including ice handling,” said a Starbucks spokesman.
Most popular: Robert Reich: This Is the Top Quality Healthcare We Need
A Caffe Nero spokesman said that a “thorough investigation” was underway and that 99 percent of its stores were rated very good, good or satisfactory by environmental health inspectors, “making us one of the most highly rated businesses on the high street.”
A Costa spokesperson said they had taken “immediate action to update our ice handling procedures.” “We were disappointed with the findings, especially as these stores are all rated very good with the top hygiene rating of five,” the spokesperson added.
More from Newsweek