Sensors, memory switches, and circuits can be encoded in a
common gut bacterium.
(July 9, 2015) The
“friendly” bacteria inside our digestive systems are being given an upgrade,
which may one day allow them to be programmed to detect and ultimately treat
diseases such as colon cancer and immune disorders.
In a paper published today in the journal Cell Systems,
researchers at MIT unveil a series of sensors, memory switches, and circuits
that can be encoded in the common human gut bacterium Bacteroides
thetaiotaomicron.
These basic computing elements will allow the bacteria to
sense, memorize, and respond to signals in the gut, with future applications
that might include the early detection and treatment of inflammatory bowel
disease or colon cancer.
Researchers have previously built genetic circuits inside
model organisms such as E. coli. However, such strains are only found at low
levels within the human gut, according to Timothy Lu, an associate professor of
biological engineering and of electrical engineering and computer science, who
led the research alongside Christopher Voigt, a professor of biological
engineering at MIT.
“We wanted to work with strains like B. thetaiotaomicron
that are present in many people in abundant levels, and can stably colonize the
gut for long periods of time,” Lu says.
The team developed a series of genetic parts that can be
used to precisely program gene expression within the bacteria. “Using these
parts, we built four sensors that can be encoded in the bacterium’s DNA that
respond to a signal to switch genes on and off inside B. thetaiotaomicron,”
Voigt says.