
Researchers compared oral microbiota, salivary cytokines, and short-chain fatty acids in persistent Covid disease using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Age- and sex-matched analyses showed no significant SCFA differences after correction, though valeric acid trended higher. Cognitive impairment and fatigue were greater in patients, highlighting chromatography’s role in probing subtle metabolic signals variations overall.




























