Current focus of the Li lab is to understand the interactions between the microbes and the human host in relation to human health and disease using a systems biology approach. Each individual carries approximately 10 times more bacterial cells than human cells (100 times more genes!). The microbes form an intricate symbiotic system with the host and play important roles in human nutrition, metabolism, and development of the immune system. By studying the genomes and the transcriptomes of the microbes living inside and on the humans, we aim to understand how microorganisms (including bacteria, archaea, small eukaryotes, and viruses) interact with the human immune system and play a role in human diseases. The human skin microbiome is a main focus that we study currently. We apply both traditional 16S rRNA sequence analysis and metagenomic analysis using the newly developed “Next Generation” high-throughput sequencing technologies to extract genomic information and transcriptional regulation of both the microbes and the human host. Molecular biology, metagenomics, and bioinformatics are the three main areas in our research.