The human stomach, the saliva, and the large and small intestines are like a rain forest, teeming with more than five thousand living species of bacteria. These bacteria cells outnumber human cells 10:1. Every moment of every day, several trillion bacteria cells interact with one another and coordinate vital functions inside the body. Together, these bacterium regulate the gastrointestinal tract and create metabolites for proper digestion and hormone regulation. They help eliminate waste and protect the blood from toxins. They respond to outside threats and initiate immune responses.

The choices we make every day influence the diversity and the quantity of these friendly microbes. Bacteria are not working against us; they are working for us. This means we must create an environment inside our bodies that encourages commensal microbial growth. This environment is created by the foods we eat, the medicines we agree to take, and the chemicals we touch, breathe, and consume.
For example, antibiotics disable vital traits of bacteria, depleting the gut of beneficial species. Antibacterial chemicals such as triclosan, glyphosate and the antibiotics in vaccines can damage the diversity of friendly microbes in the gut. When patients are diagnosed with chronic diseases and mood disorders, allopathic doctors and psychiatrists do not conduct an investigation into the patient's gut flora, which is the root pathology behind so many health issues.