We are born 90% human, 10% microbes. As we develop and grow, our microbes develop and grow with us. They grow much faster than we grow. By the time most of us die, we will have reversed the proportion of human to microbes, and we will have become 90% microbial. At the time of our death, then, it could be said that we are, indeed, more microbial than human.
In 2008, a branch of the National Institutes of Health, launched a five-year, $153 million, federally funded research project called the "Microbiome Project." It is looking at all the microbes; most are bacteria, but there are also viruses, parasites, protozoa (one-cell organisms with animal-like behavior), bacteriophages (a virus that replicates within bacteria), and yeast -- and what scientists are finding is changing the face of medicine. Take a closer look at these developments:
* Babies get a substance from breast milk that they cannot digest. This substance is oligosaccharides and babies do not have the required enzymes to digest this substance. The purpose of oligosaccharides is to deliver materials to the microbes that reside in the baby's gut! It is our infants' first prebiotic!
* Couples who live together share more microbes with each other if they have a dog, compared with couples that do not have a dog. The largest bacteria group that dogs and humans share is Betaproteobacteria.
* Animals who are fed antibiotics gain more weight than those not fed antibiotics. The research shows that antibiotics alter the bacteria that play an important role in regulating weight.
*Stress during childhood could have long-term effects on the gut microbiome. When rats and monkeys are separated from their mothers, a type of stress is created that alters the microbiota of the gut.
* Kissing involves exchanging human microbiota. Variety is key to health, and the exchange of each others' microbes has the advantage of boosting immunity. In addition, there are a wealth of other benefits to kissing. It relieves stress and releases epinephrine into the blood, resulting in increased pumping of blood, which can reduce LDL cholesterol. Kissing stimulates the production of saliva in the mouth, which helps to fight cavities. And it also stimulates a cascade of "happy" hormones, such as serotonin, dopamine, and oxytocin. These "happy" hormones aren't only important for good feelings; they also help to strengthen relationships. It has been found that those who cannot commit to a love relationship are low in oxytocin.