Lipid profiling for diagnostic purposes has become one of the promising area in relation to metabolomic approach. Although lipidomic studies about blood and cells have been sufficiently investigated, fecal and salivary lipidomic studies as potential biomarker candidates have not been thoroughly investigated yet. Recent studies have shown that the microbiome is correlated with lung cancer and that the microbiome has an effect on fecal and saliva lipids. It is inferred that feces and saliva from patients with lung cancer may have significant alterations in lipid profiles. Therefore, lipidomic analysis of fecal and saliva samples from patients with lung cancer is necessary.

In this study, lipid profiles of fecal and saliva samples from three different groups, lung cancer patient group before treatment (LCBT) (n = 19), lung cancer patient group after 6-month’s treatment (LCAT6) (n = 19), and control group (C) (n = 22), were analyzed by nanoflow ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (nUHPLC-ESI-MS/MS). Total 206 lipids were identified and 166 lipids were quantified in fecal samples. While total 634 lipids were identified and 304 lipids were quantified in saliva samples. As a result, in fecal samples, PC, PG, Cer, and CE lipids increased in LCBT group then returned to the level of the C group after treatment. On the other hand, PI and DG lipid species showed decrease in the LCBT group and didn’t recover to the level of the C group after  treatment. While in saliva samples, most of lipids decreased in the LCBT group then didn’t recover at all in the LCAT6 group. On the other hand, Cer and TG lipids increased in the LCBT group then decreased in the LCAT6 group. Cer lipids showed a similar trend in both saliva and feces.