New insight on how antibiotics affect the gut microbiome - the community of microbes that live inside us - has been published in the journal eLife.
The study in mice hints at new methods for maintaining a healthy microbiome or controlling invasion from harmful, disease-causing bacteria.
"The gut microbiome consists of a community of microbes which, when disturbed, exposes the host to risks such as infection," says first author. "While it was already known that antibiotics kill or prevent the growth of bacteria in the gut, it was not clear exactly how and when those changes affect the gut environment."
To learn more about this question, the team sought to understand what ecological changes happen to microbiota during and after treatment with broad-spectrum antibiotics - treatments that act against a wide range of harmful bacteria.
The scientists began by administering antibiotics to mice over five days to broadly inhibit their gut bacteria. They found that the gut's redox potential - a measure of the chemical environment including an estimate of how easily organisms are able to respire within it - increased under antibiotic treatment. While evidence suggested that these redox shifts were associated with the host immune system, the shifts also occurred when gut microbial communities were treated with antibiotics in an artificial gut that had no immune system.
"We also saw that as antibiotics removed bacteria and reduced their metabolic rates in the mouse gut, there was an increase in oxidising agents called electron acceptors," author explains. "This new environmental state meant that the microbial community which recolonised after treatment looked very different from the original community."
Authors found that gut redox potential increased within hours of an antibiotic dose in mice. Host and microbial functioning changed under treatment, but shifts in redox potentials could be attributed specifically to bacterial suppression in a host-free ex vivo human gut microbiota model. Redox dynamics were linked to blooms of the bacterial family Enterobacteriaceae.
The bacteria that appeared immediately following treatment, including some potentially harmful species, were able to take advantage of the electron acceptors to grow quickly. As they grew, they used up the excess resources, causing the gut environment to return to its normal state. However, this did not guarantee recovery of the original microbial community.
"Antibiotics may drive some microbe species extinct in a gut community, so new microbial immigrants from outside the mouse - in this case from an untreated mouse in the same cage - were likely needed to return the microbiota to its original state," says senior author.
Together, these results suggest new ecological models for how antibiotics reshape the gut microbiome and how redox shifts could be associated with intestinal disease, with changes in electron acceptor availability setting the stage for post-antibiotic recolonisation of gut bacteria.
"In the future, our work could help inform the development of drugs that either include chemical alterations of redox potential, or that introduce competitors for excess electron acceptors, to help treat microbial disorders or prevent antibiotic-associated infections," author concludes.
https://elifesciences.org/for-the-press/ebc692b6/scientists-reveal-how-gut-microbes-recover-after-antibiotic-treatment
https://elifesciences.org/articles/35987
Latest News
Men with gene mutations are…
By newseditor
Posted 17 May
B cell oxidative phosphoryl…
By newseditor
Posted 17 May
Human brain gene therapy us…
By newseditor
Posted 16 May
Small-molecular mimic of a…
By newseditor
Posted 16 May
Centromere structure and ch…
By newseditor
Posted 16 May
Other Top Stories
Interhemispheric transfer of working memories
Read more
Increasing political tolerance
Read more
The nanoparticles in our consumer products are dangerous to our hea…
Read more
What happens in the brain when we have bad experiences with food?
Read more
Decision-making and neurotransmitter balance
Read more
Protocols
Breast cancer-on-chip for p…
By newseditor
Posted 16 May
Methods for making and obse…
By newseditor
Posted 15 May
Mime-seq 2.0: a method to s…
By newseditor
Posted 13 May
Improved detection of DNA r…
By newseditor
Posted 09 May
Single-cell adhesive profil…
By newseditor
Posted 07 May
Publications
Obesity-induced blood-brain…
By newseditor
Posted 18 May
CRISPR/Cas9 model of prosta…
By newseditor
Posted 17 May
Modulation of host immunity…
By newseditor
Posted 17 May
Variability in cell divisio…
By newseditor
Posted 17 May
Biallelic BORCS8 variants c…
By newseditor
Posted 17 May
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar