Association between oral microbiota and suicidal ideation among vocational high school students in China

To investigate the association between oral microbiome characteristics and suicidal ideation (SI) in vocational high school students. The oral microbiota composition and abundance of the SI group (N = 45) and the matched healthy control group (N = 45) were analyzed using 16S rRNA sequencing. Demographic variables and SI assessments (measured by the Columbia Suicide Severity Rating Scale) were obtained. Bioinformatics analyses (e.g., alpha and beta diversity indices, PCoA, NMDS, and LEfSe) were performed to compare oral microbiota characteristics between the SI group and the control group. The vocational high school students with SI exhibited significantly lower alpha diversity indices in oral microbiota compared to the control group, including PD whole tree (20.56 [19.45, 21.38] vs. 21.37 [20.17, 23.27]), Chao1 (621.82 ± 66.99 vs. 672.24 ± 68.52), and observed species (426.91 ± 54.59 vs. 466.42 ± 69.75) (all p values < 0.01). Beta diversity analysis revealed distinct microbial composition between groups ( p < 0.05), with greater homogeneity in the SI group. LEfSe analysis identified increased abundances of Enterobacter, Escherichia_Shigella, and Parabacteroides in the SI group, while controls showed enrichment of Rikenellaceae and Alistipes. A decrease in oral microbiota diversity and alterations in the abundance of specific bacterial genera (Enterobacter, Escherichia_Shigella, and Parabacteroides) are associated with SI among vocational high school students. Longitudinal studies are needed to elucidate the underlying mechanisms and potential health impacts.