Antibiotics Affect Friendly Flora For Years
As reported by ScienceDaily (11/10) Antibiotics Have Long-Term Impacts on Gut Flora- Short courses of antibiotics can leave normal gut bacteria harbouring
antibiotic resistance genes for up to two years after treatment, say scientists
writing in the latest issue of Microbiology, published Nov. 3.
The researchers believe that this reservoir increases the chances of resistance
genes being surrendered to pathogenic bacteria, aiding their survival and
suggesting that the long-term effects of antibiotic therapy are more
significant than previously thought.
Antibiotics that are prescribed to treat pathogenic bacteria also have an impact
on the normal microbial flora of the human gut. Antibiotics can alter the
composition of microbial populations (potentially leading to other illnesses)
and allow micro-organisms that are naturally resistant to the antibiotic to
The impact of antibiotics on the normal gut flora has previously been thought to
be short-term, with any disturbances being restored several weeks after
treatment. However, the review into the long-term impacts of antibiotic therapy
reveals that this is not always the case. Studies have shown that high levels
of resistance genes can be detected in gut microbes after just 7 days of
antibiotic treatment and that these genes remain present for up to two years
even if the individual has taken no further antibiotics.
The consequences of this could be potentially life-threatening explained Dr
Cecilia Jernberg from the Swedish Institute for Infectious Disease Control who
conducted the review. "The long-term presence of resistance genes in human gut
bacteria dramatically increases the probability of them being transferred to
and exploited by harmful bacteria that pass through the gut. This could reduce
the success of future antibiotic treatments and potentially lead to new strains
of antibiotic-resistant bacteria."
The review highlights the necessity of using antibiotics prudently. "Antibiotic
resistance is not a new problem and there is a growing battle with multi-drug
resistant strains of pathogenic bacteria. The development of new antibiotics is
slow and so we must use the effective drugs we have left with care," said Dr
Jernberg. "This new information about the long-term impacts of antibiotics is
of great importance to allow rational antibiotic administration guidelines to
be put in place," she said.