Effects of Laurus nobilis Leaf Extract (LAURESH ® ) on Oral and Gut Microbiota Diversity in Mice

Background/Aim: The leaves of Laurus nobilis have been used for culinary purposes for many years and have recently been shown to have beneficial effects on human health by altering microbiota composition. However, the effects of L. nobilis on the diversity of microbiomes in the oral cavity and gut remain unknown. Therefore, in this study, we examined the effects of an extract of L. nobilis on the diversity of microbiomes in the oral cavity and gut in mice. Materials and Methods: C57BL/6J mice were randomly divided into two groups and fed a standard diet (SD) and a standard diet containing 5% LAURESH (R) , a laurel extract (SDL). After 10 weeks, oral swabs and fecal samples were collected. The bacterial DNA extracted from the oral swabs and feces was used for microbiota analysis using 16S rRNA sequencing. The sequencing data were analyzed using the Quantitative Insights into Microbial Ecology 2 in the DADA2 pipeline and 16S rRNA database. Results: The alpha - diversity of the oral microbiome was significantly greater in the SDL group than in the SD group. The beta -diversity of the oral microbiome was also significantly different between the groups. Moreover, the taxonomic abundance analysis showed that five bacteria in the gut were significantly different among the groups. Furthermore, the SDL diet increased the abundance of beneficial gut bacteria, such as Akkermansia sp. Conclusion: Increased diversity of the oral microbiome and proportion of Akkermansia sp. in the gut microbiome induced by L. nobilis consumption may benefit oral and gut health.