Shotgun metagenomic analysis of the oral microbiomes of children with nomaOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study asked which microbes are associated with noma, a rapidly progressive facial gangrene of children. Researchers ran the first deep shotgun metagenomic profiling of oral samples from children with acute noma. They sequenced all DNA in saliva and cheek swabs, avoiding the primer biases of earlier 16S surveys. They compared noma metagenomes to healthy saliva, applied machine learning, recovered whole genomes, and screened for antibiotic resistance genes.
Who was studied?
The cohort was 19 Nigerian children with acute noma, treated at a hospital in Sokoto, Nigeria. Most (16 of 19, 84 percent) were aged two to six years, with 10 boys and 9 girls. Disease stage ranged from ulcerative gingivitis through gangrene and early scarring. For comparison, the team used 20 publicly available healthy saliva metagenomes from adults in the USA, Japan and Denmark.
What were the most important findings?
Noma metagenomes were markedly dysbiotic, significantly enriched for Treponema, Porphyromonas and Bacteroides and depleted of Streptococcus and Rothia. A random forest classifier separated noma from healthy saliva with an AUC of 1.0. The team recovered 40 Treponema genomes across 19 species, 14 of them novel. One novel spirochete, Treponema sp. A, was found in 15 of 19 children and in no healthy sample. Metronidazole and beta-lactam resistance genes were common, including in Prevotella.
What are the greatest implications of this study?
The results give the first high-resolution microbial map of noma and flag Treponema sp. A as an organism of interest that may contribute to disease. The authors stress this is preliminary and cannot yet prove that the spirochete causes noma. Depletion of Streptococcus and Rothia hints that protective commensals may be lost, raising the idea of oral probiotics for prevention. Detected resistance to standard noma antibiotics is a treatment concern worth monitoring.