# Metabolomics reveals high fructose-1,6-bisphosphate from fluoride-resistant Streptococcus mutans

## TL;DR

This study uses metabolomics to find differences in fluoride-resistant Streptococcus mutans, identifying high levels of fructose-1,6-bisphosphate linked to acid tolerance and cariogenicity.

## Contribution

The study identifies specific metabolites, including fructose-1,6-bisphosphate, associated with fluoride resistance in S. mutans.

## Key findings

- Fourteen metabolites differed significantly between fluoride-resistant and wild-type S. mutans in the early log phase, with five identified.
- Fructose-1,6-bisphosphate levels were higher in fluoride-resistant strains under acidic conditions, indicating enhanced acidogenicity and acid tolerance.
- Pyrimidine metabolism was matched with the metabolic pathway for fluoride-resistant S. mutans.

## Abstract

Fluoride-resistant Streptococcus mutans (S. mutans) strains have developed due to the wide use of fluoride in dental caries prevention. However, the metabolomics of fluoride-resistant S. mutans remains unclear.

This study aimed to identify metabolites that discriminate fluoride-resistant from wild-type S. mutans.

Cell supernatants from fluoride-resistant and wild-type S. mutans were collected and analyzed by liquid chromatography-mass spectrometry. Principal components analysis and partial least-squares discriminant analysis were performed for the statistical analysis by variable influence on projection (VIP > 2.0) and p value (Mann–Whitney test, p < 0.05). Metabolites were assessed qualitatively using the Human Metabolome Database version 2.0 (http://www.hmdb.ca), or Kyoto Encyclopedia of Genes and Genomes (http://www.kegg.jp), and Metaboanalyst 6.0 (https://www.metaboanalyst.ca).

Fourteen metabolites differed significantly between fluoride-resistant and wild-type strains in the early log phase. Among these metabolites, 5 were identified. There were 32 differential metabolites between the two strains in the stationary phase, 13 of which were identified. The pyrimidine metabolism for S. mutans FR was matched with the metabolic pathway.

The fructose-1,6-bisphosphate concentration increased in fluoride-resistant strains under acidic conditions, suggesting enhanced acidogenicity and acid tolerance. This metabolite may be a promising target for elucidating the cariogenic and fluoride resistant mechanisms of S. mutans.

The online version contains supplementary material available at 10.1186/s12866-024-03310-8.