The Human Microbiome Project has generated 5,177 taxonomic profiles of microbes sampled from 242 people, mostly westerners (Nature 486, 207–214; and Nature 486, 215–221; 2012). It would be enlightening to extend these studies to a wider range of human populations to see how their microbial profiles vary. For example, the diversity and function of organ flora in humans could be affected by such factors as geography, food habits, environment, age, traditions and changing lifestyles.