Low-dosage antibiotic intake can disturb gut microbiota in mice.

The proportion of different microbial populations in gut microbiota (GM) is an important factor that in recent years has been linked to obesity and numerous metabolic diseases. Antibiotics are one of the factors that can dramatically alter GM at therapeutic dosages, but their effects at subtherapeutic doses have been less investigated. Here, a mouse model using a total of 60 C57BL/6J mice was used to compare the evolution of total microbiota, four phyla and two genera considered as probiotics in control mice, and mice exposed to 50 µg/kg of ampicillin, 100 µg/kg of tetracycline or 100 µg/kg of sulphadiazine. The results obtained found that the presence of antibiotics in foods, even at trace concentrations, can disturb mouse GM, causing in all antibiotics significant increases of Proteobacteria (about 2 log CFU/g) or decreases of Bifidobacterium and Lactobacillus (about 1 log CFU/g) for the cases of ampicillin and sulphadiazine. [ABSTRACT FROM AUTHOR]