Abstract: The present invention discloses a circulating multidimensional liquid chromatography and application thereof. The liquid chromatography comprises an infusion device, a sampling device, a collecting-resampling device, a chromatographic column switching device and a detecting device which are connected sequentially, wherein the collecting-resampling device comprises a collecting valve and a sample ring, and the collecting valve is connected with the sample ring; the sampling device is successively connected with the collecting valve and the chromatographic column switching device; the detecting device is also connected with the collecting valve; and the collecting valve is a three-slot three-position multi-way valve.

Abstract: The present disclosure belongs to the technical field of health food, and in particular, relates to the use of PAYCS in the regulation of intestinal flora, metabolites, and brain neurotransmitters. PAYCS remedies scopolamine-induced memory impairment in mice through target oxidation, inflammatory stress and regulation of the intestinal microorganism-metabolite-brain neurotransmitter axis through PAYCS. PAYCS improves the memory pathway through the intestinal microorganism-metabolite-neurotransmitter axis. PAYCS can significantly reduce serum MDA and LDH levels and significantly increase liver SOD content. PAYCS-H inhibits the increase of liver TNF-? and IL-1?, while PAYCS-L can only reduce the content of TNF-? in the liver. Thus, PAYCS-L changes the ratio of Bacteroides/Firmicutes and increases the relative abundance of plants such as Cactaceae and Prevotellaceae, improving the neurotransmitters associated with the metabolism of tryptophan in the brain.