Breakthrough in gut health

Riddet Institute research has led to the development of a highly original new approach with implications for disorders such as colitis and irritable bowel syndrome.

Dulantha Ulluwishewa, a Riddet Institute PhD scholar, in a world-first, has developed a dual-environment co-culture chamber that has enabled the study of anaerobic bacteria and their interaction with oxygen-requiring intestinal cells. Anaerobic bacteria are the predominant bacteria in the colon, but because of their aversion to oxygen, studies of their behaviour have been difficult.

Mr Ulluwishewa grew human intestinal cells in an environment without oxygen but with the cells receiving oxygen for survival from a separate compartment of the chamber, mimicking the cells in the intestine which receive oxygen and nutrients from the underlying capillaries.

In particular, Mr Ulluwishewa found that the survival of a key anaerobic bacterium, which has substantially lower prevalence in patients with intestinal disorders, improved greatly in the anaerobic model. He compared the effects of both live and dead bacteria on intestinal cells and showed that only the live bacterium was able to alter the permeability of the intestinal barrier. Furthermore, live cells were able to alter the gene expression of intestinal cells in a manner that reduced inflammation in the intestine more than dead cells.

Bacteria interact with the human intestinal cells at the molecular level and influence various aspects of intestinal barrier function. A well-regulated barrier is essential for health because it prevents unwanted compounds from entering the body, and controls activation of the immune system.

Mr Ulluwishewa was based at AgResearch while carrying out his studies, and graduates from Massey University in Palmerston North today.

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