Search

Purpose: to determine the metabolomics profiles in the plasma samples of primary open-angle glaucoma (POAG) patients. Methods: The plasma samples from 20 POAG patients under intraocular pressure (IOP)-lowering medication treatment and 20 control subjects were subjected to the untargeted metabolomics analysis, among which 10 POAG patients and 10 control subjects were further subjected to the oxylipin-targeted metabolomics analysis by liquid chromatography–mass spectrometry analysis. The prediction accuracy of the differentially abundant metabolites was assessed by the receiver operating characteristic curves. Pathway analysis and correlation analysis on the differentially abundant metabolites and clinical and biochemical parameters were also conducted. Results: Untargeted metabolomics profiling identified 33 differentially abundant metabolites in the POAG patients, in which the metabolism of linoleic acid, α-linolenic acid, phenylalanine, and tricarboxylic acid cycle were enriched. The correlation analysis indicated that the differentially abundant metabolites were associated with central corneal thickness, peripapillary retinal nerve fiber layer thickness, visual field defects, and lymphocytes. The oxylipin-targeted metabolomics analysis identified 15-keto-Prostaglandin F2 alpha, 13,14-Dihydro-15-keto-prostaglandin D2, 11-Dehydro-thromboxane B2, 8,9-Epoxyeicosatrienoic acid, and arachidonic acid to be significantly decreased in the POAG patients and enriched in the arachidonic acid (AA) pathway. Conclusions: This study revealed that the metabolites in the arachidonic acid metabolism pathway are differentially abundant, suggesting high IOP may not be the only detrimental factor for optic nerve cell damage in this group of POAG patients. Lipid metabolism instability-mediated alterations in oxylipins and AA pathways may be important in POAG, suggesting that oxidative stress and immune-related inflammation could be valuable directions for future therapeutic strategies. [ABSTRACT FROM AUTHOR]

Probiotic functional products have drawn wide attention because of their increasing popularity. However, few studies have analyzed probiotic-specific metabolism in the fermentation process. This study applied UPLC-QE-MS-based metabolomics to track changes in the milk metabolomes in the course of fermentation by two probiotic strains, Lacticaseibacillus paracasei PC-01 and Bifidobacterium adolescentis B8589. We observed substantial changes in the probiotic fermented milk metabolome between 0 and 36 h of fermentation, and the differences between the milk metabolomes at the interim period (36 h and 60 h) and the ripening stage (60 h and 72 h) were less obvious. A number of time point-specific differential metabolites were identified, mainly belonging to organic acids, amino acids, and fatty acids. Nine of the identified differential metabolites are linked to the tricarboxylic acid cycle, glutamate metabolism, and fatty acid metabolism. The contents of pyruvic acid, γ-aminobutyric acid, and capric acid increased at the end of fermentation, which can contribute to the nutritional quality and functional properties of the probiotic fermented milk. This time-course metabolomics study analyzed probiotic-specific fermentative changes in milk, providing detailed information of probiotic metabolism in a milk matrix and the potential beneficial mechanism of probiotic fermented milk. [ABSTRACT FROM AUTHOR]

[Display omitted] • High viable counts of PC-01 and B8589 over storage of fermented milk beverages. • Co-fermentation improves post-storage stability of fermented milk beverages. • Co-fermentation increases γ-aminobutyric acid and malate in stored products. Few studies investigated the effects of co-fermentation with bifidobacteria on post-storage changes of probiotic fermented beverages (PFBs). Thus, this study compared the post-storage changes in physicochemical index and metabolomes of PFBs produced singly by Lacticaseibacillus paracasei PC-01 (PC-01) or in combination with Bifidobacterium adolescentis B8589 (B8589). No significant differences were observed in the pH, titratable acidity, and viable cell counts between the two PFBs over 30-day storage. However, adding B8589 not only increased the stability of PFB (based on evaluating differences in PFBs metabolomics), but also the contents of beneficial amino acid metabolites, including 4-hydroxystyrene, gamma-aminobutyric acid, N -acetyl- l -aspartic acid, d -alanyl- d -alanine, and l -malic acid, after storage. Our study showed that B8589 is preferred to single-strain fermentation by PC-01. This study supports the concept of using bifidobacteria as starter culture in PFB production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effects of single and binary probiotics on growth and metabolism were compared. • Growth of B. lactis V9 was improved by co-cultivation with L. casei Zhang. • Valine, leucine and isoleucine biosynthesis may contribute to growth of B. lactis V9. • Binary probiotics had additive effect on production of short-chain fatty acids. In the present study, comparative effects of the single and binary probiotics of Lacticaseibacillus casei Zhang (L. casei Zhang) and Bifidobacterium lactis V9 (B. lactis V9) on the growth and metabolomic profiles during milk fermentation and storage has been analyzed using gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–mass spectrometry (LC–MS). The growth of B. lactis V9 can be significantly increased (p < 0.001) by co-cultivation with L. casei Zhang at the end of fermentation and storage 10 days, and valine, leucine and isoleucine biosynthesis may be a major contributor to the growth promotion of B. lactis V9. However, the growth of L. casei Zhang was not affected by co-cultivation with B. lactis V9. There were notable distinctions in volatile and non-volatile metabolomic profiles and pathways between the single and binary probiotics cultures; binary probiotics L. casei Zhang and B. lactis V9 significantly affected the volatile, non-volatile metabolic profiles compared to the single probiotics. The levels of acetic acid, hexanoic acid, butanoic acid and pentanoic acid were significantly higher (p < 0.05) in binary probiotics cultures compared to the single probiotic cultures at the storage 10 days, which indicates that binary probiotics had additive effects on the production of short-chain fatty acids during storage. This work provides a detailed insight into metabolomic profiles and growth that differ between the single and binary probiotics cultures, and it can be helpful to develop probiotic yogurt with high probiotic viability and distinct metabolomic profiles. [ABSTRACT FROM AUTHOR]

The growth behaviors and metabolomic profiles in yogurts induced by multistrain probiotics of Lactobacillus casei Zhang (LCZ) and Bifidobacterium lactis V9 (V9) at the fermentation termination and 10 d of storage at 4°C under different fermentation temperatures (37°C and 42°C) were compared using metabolomics based on liquid chromatography–mass spectrometry and gas chromatography–mass spectrometry. The growths of LCZ and V9 were affected by fermentation temperatures; the viable cell density of LCZ was higher at 37°C than that at 42°C; however, V9 was higher at 42°C. Multistrain probiotics had higher contribution to the changes in volatile and nonvolatile metabolomic profiles at 42°C than those at 37°C. At fermentation termination, there were 2 common enriched pathways increased by multistrain probiotics at 37°C and 42°C, which were biosynthesis of peptides and amino- and nucleotide-sugar metabolism. At 10 d of storage, 4 common increased enriched pathways were alanine, aspartate and glutamate metabolism; tyrosine metabolism; valine, leucine, and isoleucine degradation; and valine, leucine, and isoleucine biosynthesis. This work provided a detailed insight into different effects of different multistrain probiotics of LCZ and V9 fermentation temperatures on the growth behaviors and volatile and nonvolatile metabolomic profiles of yogurts. [Display omitted] [ABSTRACT FROM AUTHOR]