Scientists investigating new treatment options for incurable gut diseases

New insights into gut microbes will provide novel treatment options for diseases such as Crohn’s disease, according to Oxford University scientists at the Royal Society’s annual Summer Science Exhibition this week.

Inflammatory Bowel Disease (IBD), of which there are two types, Crohn’s disease and ulcerative colitis, affects around 261,000 people in the UK. In both diseases the bowels become swollen and sore and common symptoms include abdominal pain, diarrhoea (sometimes with blood), abscesses, weight loss and tiredness.

Both types of IBD are chronic, incurable diseases that flare up unpredictably, making them very difficult conditions to live with. Notable sufferers include singer Anastacia, Olympian Steve Redgrave, and TOWIE’s Sam Faiers.

IBD typically first arises in people in their twenties and the numbers affected have soared over the past decade. The number of 16 to 29-year-olds admitted to hospital with Crohn’s disease in England and Wales has increased from 4,937 in 2003/4 to 19,405 last year, according to the Health and Social Care Information Centre.

Researchers suspect that poor diets and antibiotic use could be behind the rise.

Both types of IBD are the result of a breakdown in the complex relationship between the immune system and the microbes that inhabit our gut. This means that destructive immune responses can spiral out of control and damage the intestinal tissue. As a result, around 50% of patients require surgery and the risk of colon cancer is increased twofold in people with IBD.

So far treatments have looked to reduce inflammation by targeting the immune system, but Professor Fiona Powrie FRS and her team at Oxford University are also looking to the gut microbes for new treatment options.

Through a better understanding of the 100 trillion microbes living in our guts, how they work with the immune system, and what goes wrong in IBD, Professor Powrie hopes that we might soon be able to treat IBD patients by colonising particular bacteria in the gut.

“The intestines remain the Wild West of the immune system since so little is understood about them,” explains Professor Powrie. “The gut has the highest number of bacteria within the body and our immune system must learn to live peacefully with them and yet remain sensitive to threatening pathogens. Understanding these interactions could help us to treat diseases such as IBD where this relationship is imbalanced.”

IBD is associated with a decrease in the diversity of commensal bacteria in the gut, with particular reductions in the two major protective groups, Bacteriodetes and Firmicutes, and increases in more pathogenic species belonging to Proteobacteria and Actinobacteria groups. Studies of Crohn’s disease have shown particular presence of adherent-invasive strains of E.coli.

With further identification of which microbes are pro-inflammatory and which are anti-inflammatory, a potential treatment could be developed that eliminates the pro-inflammatory ones and boosts the levels of anti-inflammatory species.

“Capitalising on how our resident bacteria normally promote gut health may offer new opportunities for the treatment of complex diseases such as IBD,” says Professor Powrie.

One of the major challenges will be taking into account how each individual’s microbiome is different, which would require a certain level of personalisation of treatment.

This could be overcome with an understanding of which bacteria tend to be present in certain subgroups of patients with different genetic predispositions.