New York, July 10 (IANS): Scientists at the Massachusetts Institute of Technology (MIT) have engineered Bacteroides thetaiotaomicron - one of the most common bacteria in the human gut - with new functions.

The manipulated bacteria were re-introduced into the intestinal tract of a mouse.

The study, appearing in the journal Cell Systems, is a starting point for designing microbes that could eventually deliver drugs or detect long-term changes in the intestines that lead to inflammatory bowel disease or other illnesses.

The idea to bio-engineer bacteria for therapeutic purposes is not new, but not all bacteria are suited for the same tasks.

The MIT group, led by synthetic biologists Timothy K. Lu and Christopher Voigt, saw that Bacteroides had the potential to express genes on demand.

"The bacteria that live in us or on us impact human health in very significant ways and we have techniques to modulate the microbiome - taking antibiotics or changing our diet -- are relatively limited," said Timothy K. Lu.

"We're hoping that with these tools to precisely engineer the intimate interface between bacteria and humans we're going to be able to tackle some major health-related problems," he said.

The eventual goal would be to engineer microbes that can alter gene expression based on signals within the intestines in humans.

"Not only you have an engineered bacterium that has colonised the mouse gut, but you can turn on which genes in the bacterium are active based on what you feed the mouse," said Christopher Voigt.

"That's really something new. It allows you to control what the bacterium is doing at the site of where it's operating," he said.