Antibiotics significantly change gut microbiota, leading to dysbiosis and changes in bacterial community compositions, which further results in a series of dysfunctions.
More...Antibiotics significantly change gut microbiota, leading to dysbiosis and changes in bacterial community compositions, which further results in a series of dysfunctions. To date, most investigations were carried out with gene-based metagenomic methods, which need to be amended with culture-based methods to identify changes in more physiology-related absolute abundances of live cells. This work adopts both culture-dependent and culture-independent methods to examine antibiotic-induced changes in gut microbiota at higher resolutions using mouse models. By following bacterial changes and antibiotic resistance daily before antibiotic exposure, after antibiotic exposure, and during recovery, several significant novel findings were made. Ampicillin and imipenem treatment led to an acute, substantial (by as many as 6.09 log folds), but temporary bloom of absolute abundances of live opportunistic pathogens Enterobacteriaceae and Enterococcus, while not affecting Lactobacillus. The absolute abundances of antibiotic-resistant pathogens followed a similar pattern with maximum increased folds of 9.46. Impact on antibiotic resistance, on the other hand, is significant and persistent. Nearly all Enterobacteriaceae turned AMP-resistant at the end of treatment, and almost 10% of Enterococcus became IPM-resistant. Different mechanisms were suggested for these two types of bacteria, despite showing similar persistence of AMR increase. These results describe the impact of antibiotics on gut microbiota from a perspective that was not previously studied to depth, with novel discoveries that, together with culture-independent high-throughput methods, improves our understanding on gut microbiota.
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