Health and Medical News and Resources

General interest items edited by Janice Flahiff

[Press release] Among gut microbes, strains, not just species, matter

From the 29 January 2015 University of Washington press release

First large-scale analysis completed of intra-species genetic variation in gut’s resident organisms

By Leila Gray  |  HSNewsBeat  |  Updated 9:00 AM, 01.29.2015

Posted in: Research

  • Gut microbiomes from different people can contain similar microbial species, but different strains, as this cartoon illustrates.Dana C, Thomas

A large community of microorganisms calls the human digestive tract home.  This dynamic conglomerate of microscopic life forms – the gut microbiome – is vital to how people metabolize various nutrients in their food, how their immune systems react to infection, and how they respond to various medications.  Moreover, imbalances in the microbiome are thought to play a significant role in many human diseases.

The collection of species occupying the gut is known to be quite personalized, and people may differ considerably in the set of species they harbor. Now new research suggests that the differences between people may go even deeper. In a paper published Jan. 29 in Cell, researchers at the University of Washington show that even when people share microbes in common, the exact strains each carries might be very different.

“Knowing more about these strain-level variations,” said Elhanan Borenstein, the senior author of this paper and an associate professor of genome sciences at the University of Washington, “is crucial for understanding the complex relationship between the composition of the community of microbes living in the human gut and its influence on health and disease.”

January 30, 2015 Posted by | Medical and Health Research News | , , , , , , , , , , | Leave a comment

[Reblog] Your Immune System Is Made, Not Born

From the 29 January 2015 post at Scientific American

New research dispels the belief that the strength of the body’s defense system is genetically programmed
Cytomegalovirus

Cytomegalovirus infection.
Credit: Yale Rosen via Wikimedia Commons

Some people seem better than others at fighting the flu, and you might suspect they were born that way. A new study of twins, however, suggests otherwise.

In one of the most comprehensive analyses of immune function performed to date, researchers analyzed blood samples from 105 sets of healthy twins. They measured immune cell populations and their chemical messengers—204 parameters in all—before and after participants received a flu shot. Differences in three fourths of these parameters depended less on genetics than on environmental factors, such as diet and prior infections. Genetics had almost no effect on how well individuals responded to the flu vaccine, judged by antibodies produced against the injected material. And among identical twin siblings, who have the same genome, immune system features differed more strikingly within older twin pairs than in younger sets. The findings, published January 15 in Cell, argue that life habits and experiences shape our body’s defenses more than the DNA passed down from our parents.

Although prior twin studies had hinted that nonheritable factors contribute to some autoimmune disorders, such as multiple sclerosis, the recent analysis was one of the first to quantify genetic and environmental effects on the general immune system. “We were surprised by the degree of environmental influence on so many components,” says Mark Davis of Stanford University School of Medicine, senior author on the new study.

One finding was particularly striking. A single environmental factor—a past infection with common cytomegalovirus—affected 58 percent of the tested parameters. Whereas the results don’t show whether these changes produce an overall stronger or weaker immune response, they do indicate “cytomegalovirus has a really profound effect,” Davis says. The Epstein–Barr virus, another microbe that frequently infects people, had no such effect.

Read the entire article at http://www.scientificamerican.com/article/your-immune-system-is-made-not-born/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Science360NewsServiceComplete+%28Science360+News+Service%3A+Complete%29&utm_content=Netvibes

January 30, 2015 Posted by | Medical and Health Research News | , , , , | Leave a comment

   

%d bloggers like this: