Salivary Microbiome Differences in Stunted and Healthy Children: A Metagenomic Analysis

This study aimed to compare the composition and diversity of the salivary microbiome in stunted and nonstunted children using 16S rRNA gene sequencing to explore the relationship between nutritional status and oral microbiota.A total of 20 saliva samples were collected from children aged 6 to 10 years, comprising two groups: stunted (n = 10) and healthy controls (n = 10). Deoxyribonucleic acid was extracted, and the V3-V4 region of the 16S rRNA gene was amplified and sequenced. Bioinformatics analysis included taxonomic assignment, calculation of relative abundance, α diversity (using Shannon and Simpson indices), β diversity (UniFrac-based principal coordinate analysis and permutational multivariate analysis of variance [PERMANOVA]), and differential abundance testing using the Mann-Whitney U test.The dominant phyla in both groups were Proteobacteria, Firmicutes, and Bacteroidota, with Proteobacteria being more prevalent in the stunted group. At the genus level, Neisseria and Veillonella were more abundant in stunted children. Notably, Veillonella was significantly elevated in the stunted group (28.6%) compared with controls (14.9%, p = 0.0376). Alpha diversity indices revealed a higher diversity trend in the stunted group, although this difference was not statistically significant (Shannon, p = 0.130; Simpson, p = 0.762). Beta diversity analysis revealed no considerable clustering between groups (PERMANOVA p > 0.05), indicating moderate interindividual variability but no clear group separation.Children with stunted growth demonstrated distinct microbial signatures in their salivary microbiota, particularly in the increased abundance of Proteobacteria and Veillonella, suggesting a potential link between chronic undernutrition and oral microbial dysbiosis. These findings underscore the need for additional studies to investigate the impact of nutritional status on oral and systemic health through the microbiome axis.