Researchers Use Computer Models to Understand how Gut Bacteria get Sick

What affects us, also affects the millions of bacteria that live in our intestines. Researchers have now developed a computer model that shows how good bacteria in the guts get sick.

The study, conducted by researchers at the Brigham and Women's Hospital (BWH), could help doctors better treat gastrointestinal diseases.

Bacteria in the intestines have gotten lot of attention for their role in regulating weight gain and for their links with autism. But, there isn't just one type of good bacteria helping out with digestion and breaking down of complex molecules. The intestinal microflora has several types of microbes - some good and some bad that have complex relations with each other and with our intestines. The latest study tried to explore this relationship.

"Our gut contains ten-times more bacterial cells than there are human cells in our body," said Lynn Bry, MD, PhD, director of the BWH Center for Clinical and Translational Metagenomics, senior study author, according to a news release. "The behavior of these complex bacterial ecosystems when under attack by infection can have a big impact on our health."

For the study, Georg Gerber at the BWH Center for Clinical and Translational Metagenomics developed computer algorithms to analyze different stages of infection when citrobacter rodentium - a pathogen - is introduced in the intestine. This organism is associated with diseases in mice that are similar to food poisoning in humans.

The computational model Microbial Counts Trajectories Infinite Mixture Model Engine helped researchers track the reaction of different types of bacterial communities in the guts.

Researchers found that population of bacteria changed during the infection. Certain species belonging to the genus mucispirillum began to disappear while bacteria from the Clostridiales and Lactobacillales families had a rise in population after the infection disappeared. 

What was interesting is that some of these changes were seen in areas of guts that weren't directly affected by the pathogen.

"From a clinical perspective, these new microbial signatures we identified could help clinicians detect early stages of inflammation or subtle persistent disease in patients with gastrointestinal disorders, such as inflammatory bowel disease," said Bry in a news release. "Moreover, several time-dependent microbial signatures we identified may be leveraged to conduct further research of other infectious and inflammatory conditions."

The study is published in the journal PLOS One.