Australian Breakthrough on Treating Gut Pain Disorders

More than 100,000 Australians live with inlammatory bowel disease (IBD). (Weyo/Adobe Stock)

When American molecular biologist Ardem Patapoutian was awarded the 2021 Nobel Prize in Physiology or Medicine, which he shared with American physiologist David Julius, his key discoveries brought new insight into decoding the biology of senses and stimuli.

Patapoutian’s research focused on identifying molecular receptors in the skin and other organs as well as how the cells respond to mechanical forces, such as stretching and pressure.

This led to his discovery of two mechanically-activated ion channels or sensors of physical force known as Piezo1 and Piezo2. The Piezo2 channel is a main detector and mediator in the sensory nervous system.

A lack of the Piezo2 channel or selectively blocking this channel may result in the inability to sense touch and provide an effective means to regulate pain sensitivity.

Patapoutian’s research led to the detection of Piezo2 in the colon by South Australian Professor Nick Spencer at Flinders University and his U.S. research partner Professor Hongzhen Hu at Washington University in St. Louis.

Findings from the research is an advancement in developing treatments for targeting pain associated with gastrointestinal disorders such as Irritable Bowel Syndrome (IBS).

“In discovering that this receptor is also in our gut, there’s the potential that selectively targeting these channels could be used for long-term silencing of pain sensations from internal organs, without the need for frequent consumption of opiate pain medications,” Spencer said.

“Chronic pain from internal organs, such as the gut or bladder, is notoriously difficult to treat. Opiates, including morphine and their derivatives have been commonly used to treat a variety of types of pain but visceral pain doesn’t respond well to the treatment and the drugs are highly addictive with a multitude of side effects.”

Many different ion channels were known to be located on the “pain-sensing” neurons that communicated from the gut to the brain, but Spencer and Hu’s study published in the neuroscience journal Neuron, identified the major ion channel in the colon that responds to mechanical stimulation, specifically being Piezo2.

From the study, Spencer and Hu are now focusing on finding a way to silence the pain sensations and hopefully produce treatment options for visceral pain also common in conditions such as irritable bowel syndrome (IBS), endometriosis and abdominal cancers, whist avoiding the problematic side effects of various steroids and painkillers that can be prescribed.

Common Gastrointestinal Disorders Affecting Australians

Irritable Bowel Syndrome (IBS) is a common condition of the digestive system that currently affects about 30 percent of Australians, with no known cause, but potential triggers include stress, infection, and medication.

Commonly referred to as a functional gastrointestinal disorder, with a new description of this condition as a disorder of the brain gut interaction, this condition is more prevalent in women than men, particularly in those aged under 40 years.

The causes of this chronic condition are often unclear, but many people find it triggers after an episode of gastroenteritis, food poisoning, infection, illness or chronic stress. Abdominal pain, bloating, diarrhoea, and constipation are all common symptoms of IBS.

Various long-term management strategies exist for managing IBS such as over-the-counter medications, dietary changes, psychological therapies, and gut-directed hypnotherapy which is gaining more attention to improve the “miscommunication” between the brain and the gut.

Dietitians Australia advised that by adopting a high fibre diet and eating more wholegrains and fruit and vegetables, symptoms of IBS can be reduced. To help identify trigger foods, a low FODMAP diet can also be adopted to specifically treat IBS over a course of two to six weeks, and should only be trialled under the supervision of an Accredited Practising Dietitian (APD).

Research into FODMAP Foods

FODMAP, which stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols, are short chained carbohydrates that are not well absorbed in the small intestine or indigestible.

These short chain carbohydrates or sugars were first identified in 2005 by researchers in the Department of Gastroenterology at Monash University.

When these carbohydrates are not well absorbed, they travel to the large intestine where they attract water into the gut and are fermented by the gut bacteria, creating gas. This leads to symptoms of bloating, constipation, pain and flatulence.

Common high FODMAP foods include garlic, onion, apples, mushrooms, bread, honey, legumes, and dairy foods.

This information of high FODMAP foods allowed the team of researchers to develop the first lowFODMAP diet, which showed in the first research studies that a low FODMAP diet reduces symptoms in people with IBS.

Gut disorders are a significant burden on the health and wellbeing of Australians, research shows that around one in five Australians experience unpleasant symptoms of irritable bowel syndrome (IBS) at some time.

Monash University reports that:

- 1 in 100 individuals have coeliac disease

- 1 in 200 individuals have inflammatory bowel disease (ulcerative colitis and Crohn’s disease)

- 1 in 7 individuals are affected by irritable bowel syndrome (IBS)

Although the strict low FODMAP diet can be used to diagnose and treat IBS in the short term, it is not recommended by Dietitians Australia to stick to it long term. It is also important to avoid unnecessary restrictions to help ensure you’re getting all the nutrients you need.