Who is N.C.B.I.

I've been spending a great many hours researching natural medicine.  Within this quest, whenever I type a subject into my favorite search engine (google, for example), NCBI appears as an authoritative source, or so it seems. 

Who is NCBI?

NCBI - The National Center for Biotechnology Information - according to wikipedia  "is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health. The NCBI is located in Bethesda, Maryland and was founded in 1988 through legislation sponsored by Senator Claude Pepper".

A publicly funded organization, therefore, information to be taken with a grain of salt.

We are told that autoimmune diseases (of which the list continues to grow) arise from unknown sources and they have no known cures.  Over and over again, we hear this from our "health care professional".


With the above in mind, how is it that they can replicate a disease (of no known origin or cure) in mice in order to test the efficacy of certain phytochemicals (derived from plants)?