Alteration of Serum Metabolites in Women of Reproductive Age with Chronic Constipation.

BACKGROUND Chronic constipation is a common gastrointestinal disease. Our previous studies confirmed that there are differences in the composition and function of gut microbiota between women of reproductive age with chronic constipation and healthy controls. However, little is known about the differences in the metabolic profile of the 2 groups. The aim of this study was to observe changes in serum metabolites and identify potential metabolic pathways in the development of chronic constipation. MATERIAL AND METHODS A total of 50 participants were included in this study: 25 female patients of childbearing age with chronic constipation who met the inclusion and exclusion criteria and 25 healthy participants as a control group. Serum samples of these participants were collected; 1 portion of the serum sample was used for clinical biochemical analysis, and the other was used for non-targeted metabolomic testing. RESULTS Compared with the control group, serum 2-hydroxyphenylacetic acid levels were higher (P<0.05) and DL-phenylalanine levels were lower (P<0.05) in the constipation group. Other amino acids, such as 5-hydroxy-l-lysine and l-pipecolic acid, were upregulated, and L-valine, glycine, L-leucyl-L-proline, and N-formylmethionine were downregulated in the constipation group. In addition, levels of the bile acid, 3b-hydroxy-5-cholenoic acid, were higher in the constipation group than in the control group. Pathway analysis showed that the significantly altered pathways were phenylalanine metabolism and glycine, serine, and threonine metabolism. CONCLUSIONS These results strongly suggest that serum metabolites and pathways are significantly altered in women of reproductive age with chronic constipation.