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

Nov 18, 2008

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. David 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
biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0060280

Source: Public Library of Science

Explore further: Free the seed: OSSI nurtures growing plants without patent barriers

add to favorites email to friend print save as pdf

Related Stories

Lifestyle determines gut microbes

Apr 15, 2014

An international team of researchers has for the first time deciphered the intestinal bacteria of present-day hunter-gatherers.

NASA to conduct unprecedented twin experiment

Apr 11, 2014

Consider a pair of brothers, identical twins. One gets a job as an astronaut and rockets into space. The other gets a job as an astronaut, too, but on this occasion he decides to stay home. After a year ...

First look at breast microbiota raises tantalizing questions

Mar 24, 2014

The female breast contains a unique population of microbes relative to the rest of the body, according to the first-ever study of the breast microbiome. That study sought to lay the groundwork for understanding how this bacterial ...

Recommended for you

Plants with dormant seeds give rise to more species

Apr 18, 2014

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers successfully clone adult human stem cells

Apr 18, 2014

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

User comments : 0

More news stories

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.