Human health is determined by two types of factors, inheritable factor and environmental factor. The inheritable factor varies in personal genome, measured by genomics. The environmental factor varies in the personal microbiota, measured by metagenomics. Personal microbiota is the interface between human body and environment. In other words, most environmental factors must interfere human body via one’s symbiotic microbiota, a mix of thousands of symbiotic microbes consisting of mostly prokaryotes along with some unicellular eukaryotes inhabiting skin and mucosae.
In a human body, subject and energy balance is constantly regulated by millions of functional genes provided by symbiotic microbiota, which hosts far more diversity than personal genome itself. In terms of present science, personal microbiota is considered as the second personal genome. Microbiota correlates with numerous chronicle systematic diseases including obesity, T2D, liver cirrhosis, IBDs, mood disorders and autoimmune conditions.
Personal microbiota has a unique dynamic equilibrium which balances instantaneity and predictivity in medical applications:
- In the short term, unlike personal genome, personal microbiota reflects one’s current health status;
- In the long term, it indicates health risks better than personal genome does.