Stalking the microbes that people carry can predict future health

WASHINGTON (AP) – We share our body with billions of microbes essential for staying healthy, but scientists are now looking more closely at how these insects can get rid of the disease.

A lesson: A single test to find out which intestinal bacteria you are hosting does not tell you much. A study published on Wednesday showed that repeated tests had allowed the microbial zoo to transform itself, which could eventually help doctors determine who was at risk of preterm birth, inflammatory bowel disease and even of diabetes.

The issue is what is called the microbiome, the community of bacteria, viruses, and fungi that live on the skin or in the intestines, nose, or reproductive tract.

"The instability of our microbiome could be an early indicator of an abnormality," said Dr. Lita Proctor, who oversees microbiome research at the National Institutes of Health.

A HOT FIELD

Many researches have identified the thousands of species that inhabit our body and interact in important ways for health, such as good digestion. Microbiomes begin to form at birth and are different depending on whether babies are born badlly or by caesarean section. And they change with age and different exposures, such as an antibiotic treatment that can eliminate beneficial bacteria as well as the bacteria responsible for infections.

But listing the differences between microbes in healthy people and those in poor health is not enough. What tasks do insects perform? Do they temporarily turn on or off if you get an infection, become pregnant, or take 20 pounds? When is a change in your microbiome not only temporary, but bad for long-term health – and is it possible to fix it?

A trio of NIH-funded studies followed three microbiome-related health issues to learn how to start finding these answers.

INFLAMMATORY DISEASES OF THE INTESTINE

For one year, a Harvard-led research team followed 132 people with conditions such as painful Crohn's disease and some healthy people for comparison. They took stool samples every two weeks and controlled the impact of microbes on the immune system or metabolism.

The researchers reported in the journal Nature that diseases were growing and shrinking. Surprisingly, a patient's intestinal microbiome has changed dramatically in just a few weeks before an outbreak.

Some of the microbes produce molecules that keep the gut lining healthy, probably one of the reasons for the worsening of the disease when these insects are gone, Proctor said.

PREMATURE BIRTH

About one in ten babies is born prematurely and researchers at Virginia Commonwealth University have discovered a warning sign in the badl microbiome, which changes during pregnancy.

The researchers followed nearly 600 pregnancies and reported in Nature Medicine that women who had given birth before term – particularly African Americans – tended to have lower than normal levels of a type of Lactobacillus bacteria as soon the first quarter.

They also harbored higher levels of some other species of bacteria, related to inflammation.

TYPE 2 DIABETES

Also in Nature, a research team led by Stanford University followed 106 people for four years, some in good health and others pre-diabetics. Up to 10% of pre-diabetics will develop diabetes each year, but it is difficult to predict who.

The researchers performed quarterly tests to detect microbial, genetic, and molecular changes, as well as tests when volunteers contracted a respiratory infection and even when some people deliberately took and lost weight. Not surprisingly, they found a list of microbial and inflammatory warning signs of brewing diabetes.

But the most interesting is that insulin-resistant people have had a delayed immune response to respiratory infections, correlated with compressed microbial reactions.

AND AFTER

The studies provide "an incredible amount of data," but much remains to be done to know if the clues will prove to be revealed, said immunologist Ken Cadwell of NYU Langone Health, who has not participated in the new research.

But the message to remember, especially since tests of intestinal bacteria at home are already sold: "If you test your microbiome Tuesday, he will talk about your microbiome Tuesday," warned Cadwell. Keeping track of important changes one day will require easier and cheaper testing, he added.

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The Health and Science Department of the Associated Press is receiving support from the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.