3b-Hydroxy-5-cholenoic acid

Identification of biomarkers and the mechanisms of multiple trauma complicated with sepsis using metabolomics

Sepsis after trauma increases the risk of mortality rate for patients in intensive care unit (ICUs). Currently, it is difficult to predict outcomes in individual patients with sepsis due to the complexity of causative pathogens and the lack of specific treatment. This study aimed to identify metabolomic biomarkers in patients with multiple trauma and those with multiple trauma accompanied with sepsis. Therefore, the metabolic profiles of healthy persons designated as normal controls (NC), multiple trauma patients (MT), and multiple trauma complicated with sepsis (MTS) (30 cases in each group) were analyzed with ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS)-based untargeted plasma metabolomics using collected plasma samples. The differential metabolites were enriched in amino acid metabolism, lipid metabolism, glycometabolism and nucleotide metabolism. Then, nine potential biomarkers, namely, acrylic acid, 5-amino-3-oxohexanoate, 3b-hydroxy-5-cholenoic acid, cytidine, succinic acid semialdehyde, PE [P-18:1(9Z)/16:1(9Z)], sphinganine, uracil, and uridine, were found to be correlated with clinical variables and validated using receiver operating characteristic (ROC) curves. Finally, the three potential biomarkers succinic acid semialdehyde, uracil and uridine were validated and can be applied in the clinical diagnosis of multiple traumas complicated with sepsis.

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.

Integrative metagenomic and metabolomic analyses reveal the role of gut microbiota in antibody-mediated renal allograft rejection

Background: Antibody-mediated rejection (AMR) remains one of the major barriers for graft survival after kidney transplantation. Our previous study suggested a gut microbiota dysbiosis in kidney transplantation recipients with AMR. However, alternations in gut microbial function and structure at species level have not been identified. In the present study, we investigated the metagenomic and metabolic patterns of gut microbiota in AMR patients to provide a comprehensive and in-depth understanding of gut microbiota dysbiosis in AMR.
Methods: We enrolled 60 kidney transplantation recipients, 28 showed AMR and 32 were non-AMR controls with stable post-transplant renal functions. Shotgun sequencing and untargeted LC/MS metabolomic profiling of fecal samples were performed in kidney transplantation recipients with AMR and controls.
Results: Totally, we identified 311 down-regulated and 27 up-regulated gut microbial species associated with AMR after kidney transplantation, resulting in the altered expression levels of 437 genes enriched in 22 pathways, of which 13 were related to metabolism. Moreover, 32 differential fecal metabolites were found in recipients with AMR. Among them, alterations in 3b-hydroxy-5-cholenoic acid, L-pipecolic acid, taurocholate, and 6k-PGF1alpha-d4 directly correlated with changes in gut microbial species and functions. Specific differential fecal species and metabolites were strongly associated with clinical indexes (Cr, BUN, etc.), and could distinguish the recipients with AMR from controls as potential biomarkers.
Conclusions: Altogether, our findings provided a comprehensive and in-depth understanding of the correlation between AMR and gut microbiota, which is important for the etiological and diagnostic study of AMR after kidney transplantation.