A Mix of Potentially Probiotic Strains Alters the Gut Microbiota in a Dose- and Sex-Dependent Manner in Wistar Rats.

Multi-strain (L.) is a potential probiotic with reported immunomodulatory properties. This study aimed to evaluate the composition, richness, and diversity of the gut microbiota in male and female rats after treatment with a multi-strain of at different doses. Thirty rats (fifteen male and fifteen female) were allocated into a control group (CTL), a group receiving at a dose of 10 CFU (Lf-10), and a group receiving at a dose of 10 CFU (Lf-10) for 13 weeks. Gut microbiota and serum cytokine levels were evaluated after treatment. Male CTL rats had a lower relative abundance of and and a lower alpha diversity than their female CTL counterparts ( < 0.05). In addition, male CTL rats had a higher (F/B) ratio than female CTL rats ( < 0.05). In female rats, the administration of at 10 CFU decreased the relative abundance of and and increased ( < 0.05). In male rats, the administration of at 10 CFU decreased the F/B ratio and increased and the diversity of the gut microbiota ( < 0.05). The relative abundance of and the alpha-diversity of gut microbiota were negatively correlated with serum levels of IL1β (r = -0.44) and TNFα (r = -0.39), respectively. This study identified important changes in gut microbiota between male and female rats and showed that a lower dose of may have more beneficial effects on gut microbiota in females, while a higher dose may result in more beneficial effects on gut microbiota in male rats.