One of the most commonly quoted bits of information about the microbiome is that bacteria outnumber human cells 10 to 1. That figure has been widespread in media and promotional posters. It’s even on a a poster I got at ASM visualizing the basics of the human microbiome. But I have had a number of professors gripe at me over the inaccuracies in calculating this ratio. A new paper reports that that ratio is more like 1:1 (here is an article talking more about the paper as well).