Find in Library

Multi-strain <i>Limosilactobacillus</i> (L.) <i>fermentum</i> 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 <i>L. fermentum</i> at different doses. Thirty rats (fifteen male and fifteen female) were allocated into a control group (CTL), a group receiving <i>L. fermentum</i> at a dose of 10⁸ CFU (Lf-10⁸), and a group receiving <i>L. fermentum</i> at a dose of 10¹⁰ CFU (Lf-10¹⁰) for 13 weeks. Gut microbiota and serum cytokine levels were evaluated after <i>L. fermentum</i> treatment. Male CTL rats had a lower relative abundance of <i>Bifidobacteriaceae</i> and <i>Prevotella</i> and a lower alpha diversity than their female CTL counterparts (<i>p</i> < 0.05). In addition, male CTL rats had a higher <i>Firmicutes/Bacteroidetes</i> (F/B) ratio than female CTL rats (<i>p</i> < 0.05). In female rats, the administration of <i>L. fermentum</i> at 10⁸ CFU decreased the relative abundance of <i>Bifidobacteriaceae</i> and <i>Anaerobiospirillum</i> and increased <i>Lactobacillus</i> (<i>p</i> < 0.05). In male rats, the administration of <i>L. fermentum</i> at 10¹⁰ CFU decreased the F/B ratio and increased <i>Lachnospiraceae</i> and the diversity of the gut microbiota (<i>p</i> < 0.05). The relative abundance of <i>Lachnospiraceae</i> 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 <i>L. fermentum</i> 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.