So you thought we were made up of tons of cells. Think again. Most of the cells in the body are not human at all. We are made up of trillions of bacteria and other microorganisms. In adults, the body carries two to five pounds of bacteria. The gut, in particular, is stuffed with them.
Researchers have produced the first genetic map of microbes that live within us and on us, referred to as the human microbiome. This may open up the possibilities to diagnose and treat sickness. This work can also help establish criteria for a healthy microbiome, which can identify how antibiotics perturb a personâ€™s microbiome and how long it takes the microbiome to recover.
Recent studies have found more than 8 million genes in the human microbiome, and more than 10,000 species of microbes! Compare that to our human genes which consists of only 22,000 genes. The interesting thing is that no 2 people share the same microbial makeup, not even identical twins. Maybe our health and the outcome of our lifestyle choices has more to do with the variation of the genes in our microbiome than in our own human genes(the human DNA of all people in the world is 99.9% alike).
We are finding that some strains of bacteria actually help our immune system function. Ways in which we’ve changed our microbial environment includes wiping out certain bacteria with antibiotics that we once thought caused disease (H. Pylori),widespread use of antibiotics, dramatic increase in the number of cesarean section deliveries, and antibacterial soaps. There is a price to pay for these good intentions.
There is a lot of work ahead to decipher the mechanisms underlying a healthy and unhealthy immune system.