Just a few hours after birth, every human being is colonized by more microbes than there are cells in the body. We are home to thousands of species of bacteria, protists, algae, fungi, molds and viruses.

Some of these microbes help us to develop blood vessels in the gut, digest our food and train immune system. Others make us sick, contributing to skin diseases, body odor, malabsorption, gastrointestinal problems, ear infections and more. Some of such bacteria can be even found in bottled water.

The composition and distribution of microbial populations depend on the age, diet, fitness, genetics, hygiene, and overall state of health of their host.

Aurametrix has one the most complete database of the species. Stay tuned for more and meanwhile check these sites for some of the players:

The Normal Bacterial Flora of Humans

IMG Genomes

The NCBI Taxonomy Database