We tend to think of bacteria as something to avoid. Germophobes beware, but our bodies are literally covered with and filled with bacteria. From our skin to the lining of our GI tract, bacteria are literally part of us. For sure, some bacteria are harmful, but many more play an important role in our health. The balance between the helpful and harmful bacteria seems to be important for health; diseases from eczema to irritable bowel syndrome can result from an imbalance.
The combination of bacteria in our bodies is known as the microbiota, the genes of which are called the microbiome. Researchers study the bacteria themselves (microbiota) and the genes (microbiome) and use both as an indicator of the balance between “good” and “bad” bacteria. This is especially relevant in the large intestine, where there has been much research into the role of gut bacteria on health.