Project description:Broad-spectrum antibiotics are frequently prescribed to children. The period of early-childhood represents a time where the developing microbiota may be more sensitive to environmental perturbations, which thus might have long-lasting host consequences. We hypothesized that even a single early-life broad-spectrum antibiotic course at a therapeutic dose (PAT) leads to durable alterations in both the gut microbiota and host immunity. In C57BL/6 mice, a single early-life tylosin (macrolide) course markedly altered the intestinal microbiome, and affected specific intestinal T-cell populations and secretory IgA expression, but PAT-exposed adult dams had minimal immunologic alterations. No immunological effects were detected in PAT-exposed germ-free animals; indicating that microbiota are required for the observed activities. Together these results indicate the impact of a single therapeutic early-life antibiotic course altering the microbiota and modulating host immune phenotypes that persist long after exposure has ceased.
Project description:Broad-spectrum antibiotics are frequently prescribed to children. The period of early-childhood represents a time where the developing microbiota may be more sensitive to environmental perturbations, which thus might have long-lasting host consequences. We hypothesized that even a single early-life broad-spectrum antibiotic course at a therapeutic dose (PAT) leads to durable alterations in both the gut microbiota and host immunity. In C57BL/6 mice, a single early-life tylosin (macrolide) course markedly altered the intestinal microbiome, and affected specific intestinal T-cell populations and secretory IgA expression, but PAT-exposed adult dams had minimal immunologic alterations. No immunological effects were detected in PAT-exposed germ-free animals; indicating that microbiota are required for the observed activities. Transfer of PAT-perturbed microbiota led to delayed sIgA expression indicating that the altered microbiota is sufficient to transfer PAT-induced effects. PAT exposure had lasting and transferable effects on microbial community network structure. Together these results indicate the impact of a single therapeutic early-life antibiotic course altering the microbiota and modulating host immune phenotypes that persist long after exposure has ceased.
Project description:Broad-spectrum antibiotics are frequently prescribed to children. The period of early-childhood represents a time where the developing microbiota may be more sensitive to environmental perturbations, which thus might have long-lasting host consequences. We hypothesized that even a single early-life broad-spectrum antibiotic course at a therapeutic dose (PAT) leads to durable alterations in both the gut microbiota and host immunity. In C57BL/6 mice, a single early-life tylosin (macrolide) course markedly altered the intestinal microbiome, and affected specific intestinal T-cell populations and secretory IgA expression, but PAT-exposed adult dams had minimal immunologic alterations. No immunological effects were detected in PAT-exposed germ-free animals; indicating that microbiota are required for the observed activities. Transfer of PAT-perturbed microbiota led to delayed sIgA expression indicating that the altered microbiota is sufficient to transfer PAT-induced effects. PAT exposure had lasting and transferable effects on microbial community network structure. Together these results indicate the impact of a single therapeutic early-life antibiotic course altering the microbiota and modulating host immune phenotypes that persist long after exposure has ceased.
Project description:The human intestinal microbiota plays an essential role in host health. Modifications in its composition and diversity could induce pathologies such as inflammatory bowel diseases (IBD). These diseases are characterized by an unbalanced intestinal microbiota (a process known as dysbiosis) and an altered immune response. Faecalibacterium prausnitzii, the most abundant commensal bacterium in the human intestinal microbiota of healthy individuals (representing more than 5% of the total bacterial population), has been reported to be lower in feces and mucosa-associated microbiota of IBD patients. In addition, we have shown that both F. prausnitzii and its culture supernatant (SN) have anti-inflammatory and protective effects in both acute and chronic colitis models. However, the host molecular mechanisms involved in these anti-inflammatory effects remain unknown. In order to address this issue, we performed DNA chip-based transcriptomic analyses in HT-29 human intestinal epithelial cells stimulated with TNF-a and exposed to F. prausnitzii SN or to BHI (growth medium for F prausnitzii).