Human Gut Microbiome Composition (image) McGill University Health Centre Share Print E-Mail Caption Human gut microbiome composition shows an enormous richness. Each circle represents a bacterial species, while the different colours mark different bacterial phyla. Credit Dr. Amir Minerbi Usage Restrictions None Share Print E-Mail 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.