How do you take your iced coffee? For some people in the United Kingdom, an investigative report from the BBC has sparked concerns that the drink may come with an unwanted add-in: a dash of fecal bacteria.
A small BBC investigation found that iced coffees from several coffee chains, including Starbucks, were contaminated with bacteria from a group with an icky-sounding name: fecal coliform.
In the investigation, undercover researchers (posing as customers) tested ice in iced coffees from 10 stores of each of three coffee chains: Starbucks, Caffe Nero and Costa Coffee. Three out of 10 ice samples from both Starbucks and Caffe Nero contained the bacteria, and seven out of 10 ice samples from Costa Coffee were contaminated with fecal coliform, the BBC reported today (June 28). [9 Disgusting Things the FDA Allows in Your Food]
The sample size was very small, and all three coffee chains told the BBC that they are looking into the problem.
But do the findings of this investigation mean there's actually poop in your iced coffee?
Simply put, no — these findings don't mean there are feces in your iced coffee, said Ben Chapman, a food safety specialist and an associate professor at North Carolina State University.
"Fecal coliform" is a large group of bacteria that, yes, can be found in feces. But these bacteria are also found in many other things in the environment, such as fruits and vegetables, Chapman told Live Science.
These bacteria are "indicators," Chapman said, meaning they indicate that something may be present that could make a person sick. But an indicator's presence doesn't signify that someone definitely will get sick, he added.
The test for fecal coliform was developed in 1904, according to a 2006 article from Microbe Magazine, a publication from the American Society for Microbiology. But since the test's inception, more specific tests have been developed to look for fecal contamination in foods.
Indeed, the fecal coliform test often leads to false positives, meaning it sometimes suggests that a food contains feces when it doesn't, according to Microbe Magazine. This is because many types of bacteria that fall into the fecal coliform group aren't necessarily found in feces. However, fecal coliform test results have been repeatedly misinterpreted by doctors, public health officials and media outlets, the article said.
A better question to ask is, are there specific germs in the drinks that cause illness?
Finding bacteria doesn't mean you've found a pathogen: "Bacteria is everywhere, and if you look for it, you're going to find it," Chapman said. But many of those bacteria are harmless, he added. Further testing — for example, looking specifically for bacteria such as E. coli — would provide more useful information.
Chapman also noted that he'd be more focused on what's going on in the coffee shops. For example, do employees wash their hands regularly and after handling potentially contaminated foods and products? Do they sanitize the equipment properly? These behaviors could be more indicative of the overall health risks the beverages and foods pose to consumers, he said.
In addition, it's unclear what type of testing the investigators used for the BBC report. Knowing these methods would provide more useful information, Chapman said. If investigators looked only for bacterial DNA, for example, you wouldn't know if the bacteria were alive or dead.
"We eat dead bacteria all the time," he added, referring to the fact that dead bacteria aren't going to make you sick.
Originally published on Live Science.