OT: Potential New Treatment for Bowel Diseases

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http://www.medicalnewstoday.com/articles/198728.php

or

http://goo.gl/GHEi

Home to a diverse range of microorganisms, a healthy human body contains at

least tenfold more bacteria cells than human cells. The most abundant and

diverse microbial community resides in the intestine, and changes to the gut

microbiota are linked with diseases such as ulcerative colitis and Crohn's

disease. In a report published online in Genome Research, researchers have

analyzed the long-term effects of gut bacterial transplantation in rats,

revealing crucial insight that will aid in the development of new treatments.

The human gut microbiome is unique to each individual and can include more than

one thousand different species. Recent evidence has implicated disruptions to

the homeostasis of the gut microbiome as playing a role in inflammatory bowel

diseases, but treatments aimed at reshaping the microbial content with

prebiotics, probiotics, or antibiotics have failed to induce stable, long-term

improvements in bacterial diversity.

An attractive alternative to these approaches is the transplantation of gut

microbiota from a healthy donor to an ill recipient. Several case reports of

biotherapy by transplantation of fecal microbiota have revealed promising

results, but the effectiveness of transplantation alone or in combination with

other treatments have not been rigorously examined.

Using rats as a model system, an international team of researchers from Spain

and the United States have now employed metagenomics to analyze the extent to

which gut microbial diversity can be reshaped by transplantation alone or in

combination with antibiotic treatment. The team sampled and pooled contents of

the cecum from several donor rats, and introduced this bacteria-rich cecal

material into the gut of recipient rats, some of which had also received

antibiotic treatment to reduce the endogenous bacterial load.

By sequencing and analyzing microbial DNA present in the feces of recipient

rats, the group could identify bacteria present and monitor changes in microbial

diversity induced by the donor microbiota. Surprisingly, they found that not

only could gut microbial diversity be successfully reshaped to resemble that of

the donor, but that these changes are long-term, persisting three months after

transplantation.

Further, although the researchers observed a reduction in microbial diversity

following antibiotic pre-treatment of the recipient, consistent with previous

findings, antibiotic treatment did not promote the establishment of the donor

community, as hypothesized. In fact, their data suggests it interfered with the

reshaping effect of the transplantation.

" Our work showed that it is possible to introduce new species in the intestinal

microbial composition ... without the need of eliminating first the endogenous

bacteria by antibiotic treatment, " said Chaysavanh Manichanh of the University

Hospital Vall d'Hebron Research Institute (Barcelona, Spain) and first author of

the study. The authors explained that because this insight is counterintuitive,

it will be extremely valuable to researchers designing novel approaches using

bacteriotherapy as an effective treatment for intestinal diseases.

Misty