Gastro bugs boost growth of Crohn's bacteria in mice
Bacterial food poisoning can encourage growth of another bacterium – but this one is associated with the chronic inflammatory bowel condition Crohn's disease. Amy Middleton reports.
Infectious diarrhoea can lay the groundwork for chronic bowel conditions to set in, according to a study in mice.
Biologists in Canada found the bacterium associated with Crohn's disease fuelled bowel inflammation after bacterial gastro was cleared away, putting the mice at greater risk for developing a chronic condition down the track.
The work, published in PLOS Pathogens, could help develop interventions for people at risk of contracting Crohn's disease.
Bowel disease is on the rise in Western society, and although genetics play a major role in this, research increasingly shows a link between bowel wellbeing and gut microbiota.
It’s known that patients who develop certain types of gastroenteritis, such as that caused by salmonella, are more prone to Crohn’s disease – an inflammation of the intestines that can cause chronic diarrhoea and abdominal pain.
Crohn’s sufferers also tend to have higher numbers of a type of gut bacteria known as adherent-invasive Escherichia coli, or AIEC.
The condition can develop years after a patient’s bout of food poisoning and the relationship between these two conditions isn’t well understood.
To shine some light on the subject, Cherrie Small at McMaster University and colleagues set about observing how mice respond to gastro.
In the test, half of the mice were infected with the AIEC gut bacteria associated with Crohn’s disease. The whole group was then exposed to acute gastro.
The mice with high levels of AIEC fared a lot worse than those without – symptoms were much more severe and levels of AIEC appeared to increase with the onset of gastroenteritis.
The researchers suggest that the AIEC gut bacteria “exploit the unique host environment imprinted by the action of pathogenic microbes that have been linked to short- and long-term risk of inflammatory bowel disease”.
They add that the study warrants research into new methods of diagnosis for at-risk patients: “Based on this work, AIEC status might be an important measure in the management of Crohn’s disease risk in individuals following episodes of food poisoning."