Localisation of nitrate-reducing and highly abundant microbial communities in the oral cavity.
Level 4 - case-series / case-control
Secondary cross-sectional analysis of observational Human Microbiome Project data
PubMed 38127919 · doi:10.1371/journal.pone.0295058
What was done
Analyzed bacterial composition across seven oral sample types from 300 individuals using data from the Human Microbiome Project. The authors evaluated the distribution, relative abundance, and diversity of 20 known nitrate-reducing bacterial genera across different oral anatomical sites.
What was found
Saliva contained the highest proportion of nitrate-reducing bacteria among all seven oral sites, with 8 genera found in higher proportions than on the tongue dorsum. The lowest proportions occurred on hard oral surfaces. Saliva also exhibited higher intra-individual variability and bacterial diversity. The abstract reported no exact numerical percentages, fold-changes, or p-values.
Why it matters
Clinical studies on the nitrate-nitrite-nitric oxide pathway often sample the tongue, but saliva provides a higher abundance of relevant bacteria through an easier, non-invasive collection method.
Limits
The abstract does not report numerical values, effect sizes, or p-values. The study evaluated relative taxonomic abundance in an existing dataset rather than measuring direct in vivo nitrate-reducing enzymatic activity or clinical nitric oxide production.
Cited by
- supports Oral bacteria on the back of the tongue convert dietary nitrates from foods like beets into nitric oxide.