Gut microbiome plays an essential role in modulating host immune responses. However, little is known about the interaction of microbiota, their metabolites and relevant inflammatory responses in the gut. By treating the mice with three different
antibiotics (
enrofloxacin,
vancomycin, and polymixin B
sulfate), we aimed to investigate the effects of different
antibiotics exposure on gut microbiota, microbial metabolism,
inflammation responses in the gut, and most importantly, pinpoint the underlying interactions between them. Although the administration of different
antibiotics can lead to different effects on mouse models, the treatment did not affect the average
body weight of the mice. A heavier caecum was observed in
vancomycin treated mice. Treatment by these three
antibiotics significantly up-regulated gene expression of various
cytokines in the colon.
Enrofloxacin treated mice seemed to have an increased Th1 response in the colon. However, such a difference was not found in mice treated by
vancomycin or polymixin B
sulfate.
Vancomycin treatment induced significant changes in bacterial composition at phylum and family level and decreased richness and diversity at species level.
Enrofloxacin treatment only induced changes in composition at family presenting as an increase in Prevotellaceae and Rikenellaceae and a decrease in Bacteroidaceae. However, no significant difference was observed after polymixin B
sulfate treatment. When compared with the control group, significant metabolic shift was found in the
enrofloxacin and
vancomycin treated group. The metabolic changes mainly occurred in
Valine,
leucine, and
isoleucine biosynthesis pathway and
beta-Alanine metabolism in
enrofloxacin treated group. For
vancomycin treatment metabolic changes were mainly found in
beta-Alanine metabolism and
Alanine,
aspartate and
glutamate metabolism pathway. Moreover, modifications observed in the microbiota compositions were correlated with the metabolite concentrations. For example, concentration of
pentadecanoic acid was positively correlated with richness of Rikenellaceae and Prevotellaceae and negatively correlated with Enterobacteriaceae. This study suggests that the
antibiotic-induced changes in gut microbiota might contribute to the
inflammation responses through the alternation of metabolic status, providing a novel insight regarding a complex network that integrates the different interactions between gut microbiota, metabolic functions, and immune responses in host.