Humans live in a mutualistic relationship with trillions of microorganisms found on our skin, nose, mouth, digestive tract, and in our urogenital area. This is known as the human microbiota. This microbiota is composed of microscopic bacteria, fungi, and viruses that outnumber our own cells by 10 to 1. Since they are much smaller than our cells they only contribute to about 1 to 3 percent of our body mass. This microbiota serves many purposes and is essential to our survival in many ways; from digesting food to keeping us strong and healthy.
Here are some fascinating facts about the human microbiota:
1. The composition of our microbiota varies from region to region; the microorganisms found in our nose may not be the same as that of our colon. In fact the microbiome changes in response to our state as well. In one study researchers studied the changes in the vaginal microbiota of pregnant women and found that the species diversity is greatly reduced during pregnancy. During childbirth the vaginal canal is the first introduction to microorganisms for the baby as the womb itself is sterile. This indicates that the vaginal canal reduces the microbial species diversity in response to a baby passing through.
2. Our brain and gut biome communicate with each other, this is known as the Gut-Brain Axis (GBA). This communication affects the functioning of our intestine. Our gut health is so important that recent studies have linked it to Autism spectrum disorder (ASD), Irritable bowel syndrome (IBS), Crohn’s disease, and ulcerative colitis.
3. Antibiotic use changes our human microbiota. Antibiotics may not discriminate between the intended bacteria making us sick and the healthy bacteria that make up our microbiota. When one is taking antibiotics the species diversity of our microbiota changes. However, fortunately, it does return back to equilibrium eventually.
4. Our gut bacteria help us digest meats and vegetables. Cellulose is found in plant cell walls and cannot be digested by us without the help of our gut microbes. Furthermore, vitamin K, vitamin b12, amino acids, and biotin are made by our gut microbiota. In fact, we are not able to get vitamin b12 from our diet or make it on our own, it is our gut microbiota that makes it.
5. Our skin microbiota is just as important as our gut microbiota. It fights off pathogens and inhibits their growth by keeping a pH of 5 which is toxic to pathogens. Furthermore, it helps alleviate inflammation and according to the latest research helps in protecting the skin from dangerous UV rays.
The Human Microbiome Project continues to research and discover more about the fascinating world of our human microbiota. Scientists believe that we have identified about 81 and 99 percent of the microorganismal genera of our microbiota. It is truly mind-boggling to think that trillions of foreign cells reside on and in our body that we never see and that they are so essential to many functions of our body.