Off the Beaten Path

In the human gastrointestinal tract, bacteria can outnumber human cells 10 to one. In other words, on a cellular level we are 90 percent bacteria. Yet until the early 2000s, microbiologists focused predominantly on microbes that cause disease rather than on those that are harmless or even beneficial.

Like an anomalous optimist declaring the glass half full, Sarkis Mazmanian, Caltech’s Luis B. and Nelly Soux Professor of Microbiology, chose early in his career to focus on the potential benefits that microbes deliver to their hosts.

For the past several years, Mazmanian’s groundbreaking investigations have shed light on the link between gut bacteria and the immune system, revealing that the absence of certain microbes points to risk for certain conditions such as inflammatory bowel disease.

“Having intellectual freedom is priceless.... We follow our own interests, our own intuition, and our own curiosity.”
- Sarkis Mazmanian, Luis B. and Nelly Soux Professor of Microbiology

Approaching science from a new perspective requires more than the notion to do so; it requires sufficient resources. By providing scholars with unparalleled access to state-of-the-art laboratories, a community of outstanding graduate and postdoctoral researchers, and ample time and funding, Caltech enables unconventional ideas to develop into groundbreaking research.

Mazmanian received early-stage support from the Caltech Innovation Initiative (CI2), an internal grant program established by the late Caltech trustee James Rothenberg and his wife, Anne Rothenberg, to fund innovative and potentially high-reward projects.

“It’s my personality to go off the beaten path and try something new,” Mazmanian says. “Having intellectual freedom is priceless…. We follow our own interests, our own intuition and our own curiosity.”

The intellectual freedom afforded to Mazmanian was recently amplified by the MacArthur Foundation, which trusts the forces of intuition and curiosity that guide Mazmanian. The foundation awarded him a MacArthur Fellowship (also known as a “Genius Grant”) in 2012, which carries with it a five-year grant of unrestricted funds.

Currently, Mazmanian and his research team are investigating the connection between microbes and the brain. While autism is identified primarily as a disorder of the brain, most individuals with the disorder also suffer from conditions associated with abnormal intestinal bacteria. Mazmanian and his colleagues are exploring how the ecosystem of bacteria in our gut may play a role in autism and other neurological conditions.

of human bodies are bacteria, on a cellular level

Giving Priorities