Gut Bacteria Interact With Intestine To Regulate Blood Supply

[Guest guest]

Hi everyone,

I found the following report of research done with mice interesting

regarding the role of bacteria in gut health.

The link to the article is here:

http://aladdin.wustl.edu/medadmin/PAnews.nsf/news/B14C4FCB1C4037CA86256C6700

7DF1A2?OpenDocument

the article is pasted below for those who might not want to go to the web

link.

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Contact: Gila Z. Reckess

(314) 286-0109

reckessg@...

Gut Bacteria Interact with Intestine to Regulate Blood Supply

St. Louis, Nov. 4, 2002 - Bacteria aren't always bad. In fact, they can be

extremely helpful partners. According to research at Washington University

School of Medicine in St. Louis, microbes found naturally in the mouse and

human gut interact with intestinal cells, called Paneth cells, to promote

the development of blood vessels in the intestinal lining.

" This study provides insights into the mutually beneficial partnerships

forged between mammals and their native microbes, " says principal

investigator I. Gordon, M.D., the Dr. J. Glaser Distinguished

University Professor and head of the Department of Molecular Biology and

Pharmacology. " These symbiotic relationships probably are most important in

the gut, which contains the largest and most complex collection of

bacteria. "

Gordon's team found that a key developmental program - orchestrating

formation of blood vessels in the gut following birth - is a responsibility

shared by intestinal bacteria and their host. The study appears in the

November 5 issue of the Proceedings of the National Academy of Sciences;

Thaddeus S. Stappenbeck, M.D., Ph.D., instructor of molecular biology and

pharmacology, is first author and Lora Hooper, Ph.D., instructor of

molecular biology and pharmacology, is co-author.

The team examined three groups of six-week-old male mice. One group of

animals was reared with normal bacteria; another group was reared without

any intestinal bacteria; a third group began bacteria-free but then were

colonized with microbes taken from intestines of normal mice.

An imaging technique called confocal microscopy provided three-dimensional

images of sections of intestinal tissue taken from each group of animals.

The images offer a clear view of cells and blood vessels in tissue samples,

and allow investigators to measure the density of capillaries, small blood

vessels in the wall of the intestine.

In mice lacking intestinal bacteria, blood vessel formation stopped early

during postnatal development. Remarkably, this developmental program

restarted and was completed just 10 days after implanting microbes into

bacteria-free mice.

Moreover, colonization by one particular type of bacteria commonly found in

normal mouse and human intestine, called Bacteroides thetaiotaomicron, or B.

thetaiotaomicron, stimulated blood vessel development as efficiently as

implantation of a whole microbial society.

The researchers also examined the pathway by which bacteria influence blood

vessel formation. They engineered mice lacking Paneth cells, normal

components of the intestinal lining that help defend the body against

attacks by harmful bacteria. Without Paneth cells, blood vessels could not

completely develop, even when microbes such as B. thetaiotaomicron were

introduced. The team concluded that B. thetaiotaomicron and Paneth cells

work together to stimulate postnatal blood vessel formation.

" Our findings illustrate the importance of co-evolution of animals and their

microbial partners, " says Gordon. " Bacteria that live in the intestine

appear to provide mammals with several necessary services for healthy

development. Unraveling the molecular foundations of these relationships may

provide new ways of preventing or treating a variety of diseases. "

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Stappenbeck TS, Hooper LV, Gordon JI. Developmental regulation of intestinal

angiogenesis by indigenous microbes via Paneth cells. Proceedings of the

National Academy of Sciences, November 2002.

Funding from the National Institutes of Health, AstraZeneca and the

Burroughs-Wellcome Foundation supported this research.

The full-time and volunteer faculty of Washington University School of

Medicine are the physicians and surgeons of -Jewish and St. Louis

Children's hospitals. The School of Medicine is one of the leading medical

research, teaching and patient-care institutions in the nation. Through its

affiliations with -Jewish and St. Louis Children's hospitals, the

School of Medicine is linked to BJC HealthCare.