A vast community of gamers who enjoyed the first-person shooter Borderlands 3 unwittingly contributed to a groundbreaking scientific advancement. In April 2020, the game introduced a minigame called "Borderlands Science" designed by developers and scientists to study the human gut microbiome.

Players rearranged and color-matched tiles representing real microbe DNA extracted from stool samples. This seemingly “silly” activity helped clear up errors in computer analysis of the complex DNA data. Over 4 million players participated, solving a staggering 135 million puzzles.

This massive effort has allowed researchers to trace the evolutionary relationships of over a million types of gut bacteria. This data will be used to develop next-generation AI programs for analyzing these microbes and potentially link them to diseases like Alzheimer's and inflammatory bowel disease.

In recognition of their contribution, both players and game developers were credited as co-authors on a research paper published in the prestigious journal Nature. "Here we have 4.5 million people who contributed to science," said the study's senior author Jérôme Waldispühl. "This result is theirs too."