Gut bacteria potential key to IBD and colon cancer prevention

Mater, UQ and Microba researchers have made a breakthrough in understanding the causes of Inflammatory Bowel Disease (IBD) and potential future treatments – identifying five strains of gut bacteria that suppress inappropriate gut inflammation and disease symptoms. 

TRI-based researchers from Mater, UQ and Microba were involved in the study, including Associate Professor Jake Begun, Dr Anne-Sophie Bergot, Professor Ranjeny Thomas, Professor Mark Morrison, Dr Paraic O'Cuiv and PhD candidate Rabina Giri. 

The research findings could pave the way for new treatments for the chronic, debilitating condition and could also potentially help prevent some forms of bowel cancer.

IBD is a chronic condition that has two predominant subtypes – Crohn’s disease and ulcerative colitis – that are characterised by relapsing and remitting gut inflammation.

It is believed to be caused by an abnormal gut bacterial composition that produces an immune response in genetically susceptible people resulting in severe symptoms and disability.

Patients are generally treated with potent drugs that suppress the immune system in a bid to relieve symptoms. Unfortunately, these drugs only work for about 50 per cent of patients.

Inflammatory Bowel Disease Research Group Leader Associate Professor Jake Begun said his team isolated bacteria found in the healthy gut and identified several species that produced a range of anti-inflammatory substances. 

"While the gut microbiome is made up of trillions of bacteria that have co-evolved with humans over time, our lab tests identified five strains that were able to suppress inflammation in blood and tissue samples from IBD patients," said Dr Begun who is also a consultant gastroenterologist at Mater Hospital Brisbane.

"Furthermore, one of these healthy gut bacterial strains produced anti-inflammatory substances that were able to reduce disease severity in a pre-clinical model by inhibiting one of the master molecular regulators of inflammation called NF-kB, without causing any side-effects."

Mater Research and The University of Queensland PhD candidate Rabina Giri said the research found good bacterial strains inhibited the pro-inflammatory enzyme NF-kB by about half.

"Most importantly, this was enough to suppress inflammation but did not cause any side effects in animal models," she said.

"Our findings could pave the way for the development of therapies for IBD that are based on the natural substances produced by ‘good’ gut bacteria which may prove to be safer than existing drugs."

More than 100,000 Australians live with IBD. About one in five people whose disease affects their colon, develops colorectal cancer – which is double the rate in the general population.

Dr Begun said the research findings were exciting, but it was also important to remember that lifestyle choices could drastically reduce a person’s risk of developing IBD and bowel cancer.

"Studies show that diets rich in fibre and low in refined sugar, ultra-processed food, and processed meat can reduce the risk of IBD and bowel cancer," he said.

"Early detection and treatment is associated with the best outcomes in colorectal cancer – so also be sure to participate in the National Bowel Cancer Screening program after age 50.

"Patients with a family history of bowel cancer, or who are at high risk of bowel cancer, should discuss screening with their general practitioner."

Redlands' woman, Lyn Savage, 56, was diagnosed with colon cancer in October 2021 and underwent treatment at Mater Hospital Brisbane.

Mrs Savage, who struggled with bowel disorders since her teenage years, said the research findings provided hope to patients living with bowel diseases.

"If researchers can find out what's causing bowel disease there's a chance that one day down the track my children or grandchildren won’t have to go through what I have experienced over the past decades," she said.

"I'm surprised how common bowel diseases are. When you have one it affects every aspect of your life, and you must modify your activities based on what's happening with the disease. It would be great if researchers like Dr Begun and his team can build on the findings to develop preventative drugs or treatments to stop this disease taking hold."

The study findings are published in Cell Reports. 

The study was funded by the US Department of Defence, The University of Queensland School of Medicine, and Mater Foundation.

This article was republished from the Mater site.