Due to the spread of resistance, antibiotic exposure
receives increasing attention. Ecological
consequences for the different niches of individual
microbiomes are, however, largely ignored.
Researchers report the effects of widely used
antibiotics (clindamycin, ciprofloxacin,
amoxicillin, and minocycline) with different modes
of action on the ecology of both the gut and the
oral microbiomes in 66 healthy adults from the
United Kingdom and Sweden in a two-center randomized
placebo-controlled clinical trial.
Feces and saliva were collected at baseline,
immediately after exposure, and 1, 2, 4, and 12
months after administration of antibiotics or
placebo.
Sequences of 16S rRNA gene amplicons from all
samples and metagenomic shotgun sequences from
selected baseline and post-antibiotic-treatment
sample pairs were analyzed.
Additionally, metagenomic predictions based on 16S
rRNA gene amplicon data were performed using PICRUSt.
The salivary microbiome was found to be
significantly more robust, whereas the antibiotics
negatively affected the fecal microbiome: in
particular, health-associated butyrate-producing
species became strongly underrepresented.
Additionally, exposure to different antibiotics
enriched genes associated with antibiotic
resistance.
In conclusion, healthy individuals, exposed to a
single antibiotic treatment, undergo considerable
microbial shifts and enrichment in antibiotic
resistance in their feces, while their salivary
microbiome composition remains unexpectedly stable.
The health-related consequences for the gut
microbiome should increase the awareness of the
individual risks involved with antibiotic use,
especially in a (diseased) population with an
already dysregulated microbiome.
On the other hand, understanding the mechanisms
behind the resilience of the oral microbiome toward
ecological collapse might prove useful in combating
microbial dysbiosis elsewhere in the body.
Many health care professionals use antibiotic
prophylaxis strategies to prevent infection after
surgery. This practice is under debate since it
enhances the spread of antibiotic resistance.
Another important reason to avoid nonessential use
of antibiotics, the impact on our microbiome, has
hardly received attention.
In this study, researchers assessed the impact of
antibiotics on the human microbial ecology at two
niches.
Scientists followed the oral and gut microbiomes in
66 individuals from before, immediately after, and
up to 12 months after exposure to different
antibiotic classes. The salivary microbiome
recovered quickly and was surprisingly robust toward
antibiotic-induced disturbance. The fecal microbiome
was severely affected by most antibiotics: for
months, health-associated butyrate-producing species
became strongly underrepresented.
Additionally, there was an enrichment of genes
associated with antibiotic resistance. Clearly, even
a single antibiotic treatment in healthy individuals
contributes to the risk of resistance development
and leads to long-lasting detrimental shifts in the
gut microbiome.
For more information
Zaura E, Brandt BW, Teixeira de Mattos MJ, Buijs MJ,
Caspers MPM, Rashid MU, Weintraub A, Nord CE, Savell
A, Hu Y, Coates AR, Hubank M, Spratt DA, Wilson M,
Keijser BJF, Crielaard W. 2015.
Same exposure but two radically different responses
to antibiotics: resilience of the salivary
microbiome versus long-term microbial shifts in
feces.
mBio 6(6):e01693-15. doi:10.1128/mBio.01693-15.
Link...
MDN |