TikTok has been charged by the European Commission with failing to protect users’ mental health by exposing them to a relentless stream of content that risks worsening eating disorders and anxiety in a case that strikes at its business model.

Issuing a preliminary ruling on Friday, the EU regulator said TikTok’s algorithm “can be harmful” and was leading young and vulnerable users “down rabbit holes they cannot easily escape from”.

The Chinese-owned short-video platform, which has 189 million users in the EU, was found to have failed to prevent users from being served up repetitive content on themes such as body image or isolation, which can lead to anxiety, sadness, worsen existing eating disorders or mental health problems.

Officials said their investigation focused on legal content, where a single video might not be problematic, but the cumulative effect of watching scores of them on one theme could damage users’ mental health.

TikTok’s safeguards to mitigate the risks of “rabbit-hole effects” – where…