Scientists have figured out how cholera bugs invade our guts, infecting millions and killing more than 100,000 people worldwide every year, reveals a study.

The discovery potentially paves the way for more effective treatments against the bug, Vibrio cholerae, which is able to colonise the gut after consumption of contaminated water or food.

The bug secretes a toxin that causes watery diarrhoea and ultimately death if not treated rapidly, the Journal of Biological Chemistry reported.

Colonisation of the intestine is difficult for incoming bugs as they have to compete to gain a foothold among the trillions of other bacteria already on the site.

A team led by biologist Gavin Thomas from the University of York, England, investigated how Vibrio cholera gains this foothold with the help of sialic acid, a sugar, present on the gut cells surface, according to a university statement.

Their associates, led by Fidelma Boyd, professor at the University of Delaware, US, had shown previously that eating sialic acid was important for the bug's survival in animal models, but the mechanism by which it recognises and takes up the sialic was unknown.

The York research demonstrates that the pathogen uses a particular kind of transporter called a TRAP transporter to recognise sialic acid and take it up into the cell.

The transporter has particular properties that are suited to scavenging the small amount of sialic acid available. The research also provided some important basic information about how TRAP transporters work in general.

"This work continues our discoveries of how bacteria that grow in our body exploit sialic acid for their survival and help us to take forward our efforts to design chemicals to inhibit these processes in different bacterial pathogens," said Thomas.