Google Inc. has embarked on what may be its most ambitious and difficult science project ever: a quest inside the human body, the Wall Street Journal reports.

Called Baseline Study, the project will collect anonymous genetic and molecular information from 175 people—and later thousands more—to create what the company hopes will be the fullest picture of what a healthy human being should be.

The early-stage project is run by Andrew Conrad, a 50-year-old molecular biologist who pioneered cheap, high-volume tests for HIV in blood-plasma donations, according to theJournal.

Dr. Conrad joined Google X—the company's research arm—in March 2013, and he has built a team of about 70-to-100 experts from fields including physiology, biochemistry, optics, imaging and molecular biology.

The hope is that this will help researchers detect killers such as heart disease and cancer far earlier, pushing medicine more toward prevention rather than the treatment of illness, the Journal says.

"With any complex system, the notion has always been there to proactively address problems," Dr. Conrad said. "That's not revolutionary. We are just asking the question: If we really wanted to be proactive, what would we need to know? You need to know what the fixed, well-running thing should look like."

The project won't be restricted to specific diseases, and it will collect hundreds of different samples using a wide variety of new diagnostic tools. Then Google will use its massive computing power to find patterns, or "biomarkers," buried in the information. The hope is that these biomarkers can be used by medical researchers to detect any disease a lot earlier.

Dr. Conrad and Dr. Gambhir admit that the project is a giant leap into the unknown. That's because the human body is so complex and so little is known about the interplay between DNA, enzymes and proteins and how environmental factors like diet influence this. The initiative may reveal biomarkers that tell researchers little about diseases, for instance.

Google said the information from Baseline will be anonymous and its use will be limited to medical and health purposes. Data won't be shared with insurance companies, the company added.