TTR and cholelithiasis: In order to explore whether the serum biochemical indicators are related to the abundances of intestinal microbes in cholelithiasis subjects, the relevant information of such indicators including total bilirubin, direct bilirubin, total bile acid, alkaline phosphatase, γ-glutamyl transpeptidase, cystatin C, prealbumin, lactate dehydrogenase, glutamate dehydrogenase, etc., was collected.