What cures you may also ail you: Antibiotics, your gut and you

[Guest guest]

Colleagues, the following is FYI and does not necessarily reflect my own

opinion. I have no further knowledge of the topic. If you do not wish to

receive these posts, set your email filter to filter out any messages

coming from @nutritionucanlivewith.com and the program will remove

anything coming from me.

---------------------------------------------------------

Public release date: 17-Nov-2008

http://www.eurekalert.org/pub_releases/2008-11/plos-wcy111208.php

Contact: Sally Hubbard

press@...

Public Library of Science

What cures you may also ail you: Antibiotics, your gut and you

We are always being told by marketers of healthy yogurts that the human

gut contains a bustling community of different bacteria, both good and

bad, and that this balance is vital to keeping you healthy. But if you

target the disease-causing bacteria with medicine, what might be the

collateral damage to their health-associated cousins that call the human

body home?

A new study by Les Dethlefsen et al, to be published this week in the

online open-access journal PLoS Biology, looks into the changes that

happen in the human gut when it is exposed to the widely used

antibiotic, ciprofloxacin. Ciprofloxacin is prescribed for a number of

conditions, including common afflictions such as urinary tract

infections. It was previously believed to cause only modest harm to the

abundant beneficial bacteria of the human body.

To investigate ciprofloxacin's effect on health-associated bacteria a

team of researchers, led by Dr. Relman of Stanford University,

catalogued types of bacteria present in the faeces of volunteers who

were undergoing a course of treatment of ciprofloxacin. The DNA-analysis

technique, massively-parallel pyrosequencing, was central to their

approach, which is outlined in a companion paper scheduled for

publication in PLoS Genetics on Friday the 21st of November. With this

technique, the researchers examined the diversity and abundance of

bacteria present in human faeces, identifying over 5,600 different

bacterial species and strains. The dramatically increased detection

power of this approach allowed the team to track carefully the changes

in the gut's bacterial community both during and after the course of

treatment.

The study found that while the patients were undergoing treatment the

overall abundance of approximately 30% of the species and strains was

significantly affected. The effects varied greatly between individuals,

with two of the subjects showing a strong reduction in diversity. The

effects didn't stop there. Once the course of treatment had been halted,

it took up to four weeks for most strains of gut bacteria to return to

their pre-treatment levels. Even six months later, some types of

bacteria had not managed to return to pre-treatment abundance levels.

During this time of population upheaval none of the patients in the

study reported signs of gut-related problems.

The bacteria present in the human gut are responsible for various

aspects of host nutrition, metabolism and immune responses. This study

reveals aspects of resiliency in the indigenous microbiota when

subjected to perturbation, but underlines the concern that antibiotic

treatment, especially when prolonged or repeated, may have long-lasting

effects on overall wellbeing that could go un-noticed.

###

Citation: Dethlefsen L, Huse S, Sogin ML, Relman DA (2008) The pervasive

effects of an antibiotic on the human gut microbiota, as revealed by

deep 16S rRNA sequencing. PLoS Biol 6(11): e280.

doi:10.1371/journal.pbio.0060280

http://biology.plosjournals.org/perlserv/?request=get-document & doi=10.1371/journ\

al.pbio.0060280

CONTACT:

Relman

Stanford University

Deptartment of Microbiology & Immunology, and of Medicine

VA Palo Alto Health Care System 154T

Building 101, Room B4-185, 3801 Miranda Avenue

Palo Alto, CA 94304

relman@...

--

ne Holden, MS, RD

" Ask the Parkinson Dietitian " http://www.parkinson.org/

" Eat well, stay well with Parkinson's disease "

" Parkinson's disease: Guidelines for Medical Nutrition Therapy "

http://www.nutritionucanlivewith.com/