PHOTO: Robb Mandelbaum
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Twenty years ago, after Bob Quinn began growing
Khorasan wheat, an ancient and vanishing Egyptian grain
with an oversized, banana-shaped kernel, he noticed
something unusual. Not only could people who have
trouble eating regular wheat digest Khorasan, but it
actually made them feel better. Today, food from the
grain, which the Montana farmer has branded Kamut, is
sold in health stores around the world
and is prescribed by some doctors as a
treatment for wheat allergies. Yet, says Quinn, “we
don’t know how it’s really acting in the
body to create these differences.”
Now, though, two scientists at the Institute for Food
Research (IFR) in Norwich, England, might be able to
offer some answers. Later this year, Martin Wickham and
Richard Faulks plan to feed Quinn’s pasta to the world’s
first and most sophisticated artificial stomach and
compare the output to that from a meal of conventional
pasta. Not only does the IFR’s “model gut,” as it’s
called, break down food with the proper quantities of
enzymes and acids, it also mimics the physical
motion—the mixing and shearing—that occurs inside the
stomach. Besides clarifying our understanding of
digestion, the invention may revolutionize the way
processed foods are designed and how drugs are
delivered. Since the machine began operating, in
November 2006, some 10 to 15 companies have used it to
test their products.
The model gut originated with a study that aimed to
uncover how carotenoids—pigments that color foods such
as tomatoes and carrots—are released from food and
absorbed by the body. Faulks, a food chemist and
nutritionist, and Wickham, a chemist specializing in
colloidal mixtures, were unable to measure exactly what
transpires in the stomach. Clinical trials are difficult
and expensive. “You can’t obtain samples of solid dinner
because you can’t easily aspirate them—you can’t suck
them up through a pipe,” says Faulks. “You have to
physically get in there. This, of course, then generates
huge ethical problems.”
Advances in echo-planar imaging, an ultrafast type of
magnetic resonance imaging, provided a breakthrough.
This technique relies on just a single excitation of the
molecules under study rather than the sequence of energy
bursts in a traditional MRI, allowing it to capture 10
images or more each second. Echo-planar imaging “allows
us to collect data from people’s stomach and small
intestine while they’re digesting foods,” says Wickham,
without invasive probes.
Given the mystery that has shrouded the workings of
the stomach, it’s fitting that the bulk of Faulks and
Wickham’s model is behind smoky plastic: a literal black
box. One day in October 2007, the scientists agree to
demonstrate the device for IEEE Spectrum. They place two
cans of soup on the countertop and prepare to feed the
machine a late-morning meal.
The machine is the result of nearly a decade’s worth
of effort and more than US $2 million, financed by the
British government. After capturing data from hundreds
of volunteers and drawing up a provisional design,
Wickham and Faulks went to engineers to actually build
the device. “We had to help specify what materials were
to be used, what size things were, how fast things
moved,” says Wickham. ”Unless you can describe it to an
engineer, an engineer can’t create it,” adds Faulks.
With Wickham at the computer manning the controls,
Faulks pours a can of chunky chicken and vegetable soup
into the blue funnel encased in a clear plastic cylinder
at the top of the machine. This serves as the fundus,
the curved, upper portion of a human stomach where newly
arrived, chewed food gets gently massaged.
To measure this movement, Faulks and Wickham prepared
beads of various densities made from agar, a seaweed
gel. “We got volunteers to swallow these, and then we
MRI imaged the stomach to see when the stomach could
break them up,” says Faulks. Still, he adds, designing
the fundus was the most challenging aspect of the
project. In the model, the massaging is replicated by a
pressurized warm-water bath that surrounds the blue
envelope, squeezing it to a rhythm that Wickham now sets.