Salivary lipid metabolism in periodontitis patients with spleen-stomach dampness-heat syndrome.

BACKGROUND

Spleen-stomach damp-heat syndrome is one of the most common syndrome types in periodontitis from traditional Chinese medicine theory. However, its pathological mechanism is still uncertain. Tissue metabolism is driven by microbes in the host and its microenvironment. Hostmicrobe-metabolism is an interacting and closely related complex. Lipid metabolomics can find lipid metabolites in disease or healthy state, which is beneficial to explore the metabolic process and change mechanism of lipids that may be involved in organisms in healthy or disease state from the perspective of systems biology.

METHODS

In this study, 10 patients in the periodontitis group (CP), 10 patients in the periodontitis with spleen-stomach dampness-heat syndrome group (SP) and 10 patients in the healthy group (H) were recruited for participation, whose unstimulated saliva was collected. The differential metabolites between the groups were detected by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and screened out based on the variable importance in projection (VIP) combined with the P-value and fold change (FC) value of univariate analysis. Finally, KEEG pathway enrichment analysis was performed on these differential metabolites.

RESULTS

A total of 1131 metabolites were detected in saliva in this study. 497 metabolites were significantly up-regulated in periodontitis, mainly plasma-membrane-associated lipids, unsaturated fatty acids and oxidized lipids. Compared with the healthy group, the lipid metabolism pathways of periodontitis with or without spleen-stomach dampness-heat syndrome group were mainly characterized by significant enrichment of glycerophospholipid metabolism and unsaturated fatty acid metabolism such as arachidonic acid metabolism.

CONCLUSION

Compared with periodontally healthy patients, periodontitis with or without spleen-stomach dampness-heat syndrome can cause changes in lipid metabolism in saliva samples of patients. These metabolites are mainly plasma membrane lipids, unsaturated fatty acids and oxidized lipids quality. These lipids may be potential biomarkers of periodontitis. The downstream metabolites of unsaturated fatty acids in the saliva samples of patients with periodontitis and spleen-stomach dampness-heat syndrome were abnormal, and the oxidized lipid (±)5-HETE was significantly abnormal. We speculate that this may be related to the increased state of oxidative stress in saliva samples in disease states.