Massey research improves gut permeability test
Caption: Professor Roger Lentle and doctoral researcher Ivana Sequeira
It may be a simple test – drink sugary water, pee and wait for the results. But a Massey nutrition researcher’s
innovative experimental work to refine and improve the accuracy of the test – widely used by doctors to monitor people
with chronic bowel conditions – has earned her international recognition.
College of Health doctoral student Ivana Sequeira measured the human gut’s permeability to tracer sugars during a
three-year study.
Her research at Massey’s Institute of Food, Nutrition and Human Health will mean a significant improvement in accuracy
when assessing changes in gut permeability in illnesses such as Chrohn’s, Coeliac and Inflammatory Bowel diseases. About
15,000 people in New Zealand are affected by inflammatory bowel disease, according to the Ministry of Health.
Her work has been praised in the reputable Clinical and Experimental Pharmacology and Physiology journal, which
published her research. In a rare editorial piece, titled Sweet transition from clinical to basic physiology, editor Dr
Klaus Michel says Ms Sequeira’s research is good example of scientific studies that are “paving the way for valuable
improvements of existing methods to benefit patients and clinicians.”
Gut permeability determines what nutrients the body absorbs, and is crucial for overall health. Permeability, and the
cells that control it, can be disturbed by harmful bacteria which prevents optimum nutrient absorption and can lead to
immune dysfunction and disease, says Roger Lentle, a professor of digestive biomechanics who supervised the research.
“The existing clinical tests of gut permeability are fairly crude and may not be sufficiently sensitive to identify the
early stages of relapse, or to identify which section of the bowel is involved, “ he says.
Ms Sequiera measured the rate at which two harmless sugar probes (mannitol and lactulose) were absorbed to track
permeability in the small and large intestine. To check whether the modified test would pick up subtle changes in
permeability she repeated it after each subject had taken a single dose of aspirin, used to mimic a slight inflammatory
effect. She found that the test could identify a significant increase in the permeability in the small but not the large
intestine.
She subsequently conducted a further study to check her results simultaneously dosing her subjects with the tracer
sugars and a ‘smart pill’ – a radio transmitter pill that gave signals that enabled the researchers to tell whether it
was in the small or the large intestine.
“This research puts New Zealand on the map internationally in terms of cutting edge clinical science,” says Professor
Lentle. He says the modified test could also be used to test the effects of a range of foods and food supplements on gut
permeability, and to relate these to conditions such as obesity.
ENDS