Amoxicillin-induced gut dysbiosis influences estrous cycle in mice and cytokine expression in the ovary and the caecum.

Gut dysbiosis is caused by several factors, including the use of antibiotics. Since intestinal dysbiosis is associated with a wide range of immunopathological and reproductive conditions, the main goal of this study was to evaluate amoxicillin-induced gut dysbiosis and its influence on the estrous cycle in mice.Mice were treated with amoxicillin or PBS and faecal microbiota was evaluated by 16S rDNA metagenomic sequencing. The estrous cycle was evaluated by vaginal cytology, vaginal opening and flow cytometry. After the induction of gut dysbiosis, the ovaries and the caecum were analysed to differential expression of IL-1β and IL-10 genes and histological analysis.Amoxicillin treated mice presented differing bacterial groups in the faecal microbiota when compared to the PBS treated group indicating that amoxicillin treatment induced gut dysbiosis and they gained weight. The vaginal cytology analysis showed that amoxicillin-induced gut dysbiosis decreased the number of cells but increased the relative number of leukocytes and altered the estrous cycle. IL-1β was shown to be up-regulated in the caecum and in the ovary of the dysbiotic mice. On the other hand, IL-10 expression was shown to be diminished in both organs of the dysbiotic mice. The oocyte area from dysbiotic group presented lower than non-dysbiotic mice with increasing thickness of the pellucid zone. The follicular teak from dysbiotic mice showed lower thickness than non-dysbiotic mice.The results indicate that amoxicillin induces gut dysbiosis and influences the estrous cycle and the inflammatory status of the ovary and the caecum.