New York University's Martin Blaser, among others, is concerned about antibiotics' effects on the human microbiome, reports The New York Times. Blaser notes that when mice are given antibiotics, mimicking what is given to children to treat ear and throat infections — which is also enough to kill the gut bacterium H. pylori — they have an increase in body fat. While Barry Marshall from the University of Western Australia points out that people reacquire the flora they've lost, he says that antibiotics are overused. The Times adds that the US National Institutes of Health is funding the Human Microbiome Project to study the diversity of microorganisms living in and on the human body. "We need to get an understanding of how our microbial communities operate and what to feed them so they will bloom again," adds David Relman from Stanford University.