Clàudia Fontserè (IMAGE) Universitat Pompeu Fabra - Barcelona Caption Clàudia Fontserè, first author of the study and researcher at IBE, processing faecal samples in the lab. Credit: Clàudia Fontserè. Credit Clàudia Fontserè Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.