Bacteroides thetaiotaomicron (white) living on mammalian cells in the gut (large pink cells coated in microvilli). (Credit: Janet Iwasa, Broad Visualization Group, MIT Media Lab)

Bacteroides thetaiotaomicron (white) living on mammalian cells in the gut (large pink cells coated in microvilli).
(Credit: Janet Iwasa, Broad Visualization Group, MIT Media Lab)