Untargeted metabolites analysis in extracted intestinal liquid using GC-MS and LC-MS

The intestinal biofluids were extracted using the method reported by Wu et al, the entire small intestine tissues were isolated from healthy males and females and collected tissues were rinsed with phosphate buffered saline (PBS). The suspension containing intestinal content was centrifugated at 12,000 rpm for 10 min with several cycles to remove insoluble substances. The supernatant was collected and stored at -80℃ until use.

In remained group, intestinal fluid extracted was incubated with 10 mg/ml PSNPs (final concentration) for 2 h at 37℃, total group (without PSNPs addition, represent the initial metabolites content and composition) was incubated with equal volume of ultrapure water. To avoid the differences caused by ultrafiltration centrifugation, both intestinal fluids with or without PSNPs incubation were subjected to same ultrafiltration centrifugation procedure (14, 000 rpm for 15 min). Filtrate was collected and detected by GC-MS (Agilent, USA) and LC-MS (Waters/Thermo Fisher Scientific, USA).