Abstract
Humans exist and other species coexist with a variety of microorganisms called the microbiota. Some of these produce needed nutrients such as vitamin K and short-chain fatty acids. The majority of the microorganisms are harmless, yet some of these organisms may play a role in chronic degenerative and other diseases. We do not know the identity of all of the microbiota that coexist with our bodies, yet we are beginning to learn that they can have far-reaching effects on our health and well-being. They may be involved in eliciting the inflammatory state, may be responsible for certain injuries, and may elicit signals that travel to the immune system that in turn serve as "triggers for the autoimmune response. The microbiotia can also generate signals to the brain that in turn may explain their associations with the development of obesity, heart disease, and diabetes. Research continues to describe the identity, location, and function of the microbiota. Strategies to enhance the favorable roles of the microbiota while suppressing the deleterious effects are being studied.