The Obama administration recently announced it will spend over a hundred million dollars on deepening our knowledge of the human microbiome - the bacteria, fungi, viruses and other organisms which make their home in and on our bodies. Bridget Kendall is joined by three people whose work in different ways enriches our appreciation of the world of human microbiota - the epidemiologist Mark Woolhouse, microbiology educator Christine Marizzi and gut flora researcher Jeroen Raes.

(Photo: The NYC Biome MAP part of the Collective Urban Biome MAP project. Credit: Genspace NYC and The DNA Learning Center)