Mouth Bacteria Change Their Diet When Diseased: New Method to Predict Illness

It turns out that the bacteria in your mouth can drastically change when you're diseased. Scientists have discovered that mouth bacteria could be the perfect way to detect illnesses that range from periodontitis to diabetes to Crohn's disease.

"What we were trying to figure out is how do these bacteria act when you're healthy, and how do they act when they're in a diseased state," said Marvin Whiteley, one of the researchers, in a news release. "The really big finding is that they do act very differently."

In order to examine these bacteria in detail, the scientists used shotgun metagenomic sequencing, which is a non-targeted way to study all the genetic material of bacterial communities. More specifically, the researchers analyzed the RNA collected from communities with supercomputers.

About 10,000 different species of bacteria live inside each person. This is collectively known as the human microbiome.

"The easiest way to think of it is just the collection of bacteria that are in or on your body," said Whiteley. "We think of it as not only the bacteria, but the genetic composition. What's their DNA? And from that we can infer what these bacteria might be doing for us."

In this case, the researchers found that bacteria act differently when one is healthy compared to when diseased. The main thing that changes is the bacteria's metabolism. For example, a species of bacteria that ate one thing can switch to another to feed on if diseased.

"What our study says is that it doesn't really matter what bacteria you have, because the communities are acting very similarly," said Whiteley. "So a healthy community has this metabolism, no matter what the members are. And a diseased community has a very different metabolism, no matter what the members are. It's this conservation of a metabolic community."

The findings could be a new way to test for certain diseases. In fact, scientists could develop biomarkers that may predict if someone is going to get sick. This could help give patients faster treatments and could even allow preventative measures to be administered.

The findings are published in the journal mBio.