Most websites that provide information about probiotics are unreliable and often tout unproven health benefits, a study finds.

After examining the first 150 websites turned up by a Google search, researchers concluded that the vast majority were run by companies advertising products or news outlets that offered incomplete information.

To take a closer look at the information consumers might be finding online, UK and Belgian researchers cleared histories and cookies from a computer and then searched on Google for ‘probiotics’. They focused their analysis on the top 150 results.

Web pages were rated by four criteria: the presence of links to scientific references supporting health claims, cautionary notes about the level of evidence for alleged benefits, information about safety considerations and information on the regulatory status of the product.