Metabolites

The availability of omics data providing information from different layers of complex biological processes that link nutrition to human health would benefit from the development of integrated approaches combining holistically individual omics data, including those associated with the microbiota that impacts the metabolisation and bioavailability of food components. Microbiota must be considered as a set of populations of interconnected consortia, with compensatory capacities to adapt to different nutritional intake. To study the consortium nature of the microbiome, we must rely on specially designed data analysis tools. The purpose of this work is to propose the construction of a general correlation network-based explorative tool, suitable for nutritional clinical trials, by integrating omics data from faecal microbial taxa, stool metabolome (1H NMR spectra) and GC-MS for stool volatilome. The presented approach exploits a descriptive paradigm necessary for a true multiomics integration of data, which is a powerful tool to investigate the complex physiological effects of nutritional interventions. Full article

Tobacco smoking is the leading cause of preventable death. Numerous reports link smoking in pregnancy with serious adverse outcomes, such as miscarriage, stillbirth, prematurity, low birth weight, perinatal morbidity, and infant mortality. Corollaries of consuming nicotine in pregnancy, separate from smoking, are less explored, and the mechanisms of nicotine action on maternal–fetal communication are poorly understood. This study examined alterations in the maternal gut microbiome in response to nicotine exposure during pregnancy. We report that changes in the maternal gut microbiota milieu are an important intermediary that may mediate the prenatal nicotine exposure effects, affect gene expression, and alter fetal exposure to circulating short-chain fatty acids (SCFAs) and leptin during in utero development. Full article

Preterm birth (PTB) is a social problem that adversely affects not only the survival rate of the fetus, but also the premature babies and families, so there is an urgent need to find accurate biomarkers. We noted that among causes, eubiosis of the vaginal microbial community to dysbiosis leads to changes in metabolite composition. In this study, short chain fatty acids (SCFAs) representing dysbiosis were derivatized using (N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide, MTBSTFA) and targeted analysis was conducted in extracted organic phases of cervicovaginal fluid (CVF). In residual aqueous CVF, polar metabolites produced biochemistry process were derivatized using methoxyamine and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), and non-targeted analysis were conducted. Nine SCFAs were quantified, and 58 polar metabolites were detected in 90 clinical samples using gas chromatography/mass spectrometry (GC/MS). The criteria of statistical analysis and detection rate of clinical sample for development of PTB biomarkers were presented, and 19 biomarkers were selected based on it, consisting of 1 SCFA, 2 organic acids, 4 amine compounds, and 12 amino acids. In addition, the model was evaluated as a suitable indicator for predicting PTB without distinction between sample collection time. We hope that the developed biomarkers based on microbiota-derived metabolites could provide useful diagnostic biomarkers for actual patients and pre-pregnancy. Full article

This study aimed to determine blood and milk metabolic parameters and their correlations for the purpose of evaluating metabolic status in dairy cows. Blood and milk samples were collected from 100 Holstein dairy cows during morning milking. The cows were allocated to four groups according to the production period, including cows in early (n = 18), full (n = 26), mid (n = 25) and late (n = 31) lactation. The value of non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), glucose, triglycerides (TG), total cholesterol (TChol), total protein (TP), albumin, globulin, urea, total bilirubin (TBil), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and lactate dexydrogenase (LDH) in the blood were determined. The following milk parameters were measured: fat, protein, lactose, urea, AST, ALT, ALP, GGT, LDH and BHB. Blood serum NEFA, BHB, TBil, AST, ALT, ALP and LDH were higher in early lactation cows, whereas glucose, TP, globulin and urea levels were significantly lower in early lactation cows. Milk fat and lactose levels were lower in early lactation cows, whereas milk protein and the activities of AST, ALT, ALP and LDH in milk were highly greater in early lactation cows. Milk fat was positively correlated with glucose, TP and TG, and negatively correlated with BHB, NEFA, TBil, ALT, LDH and ALP levels in the blood. Enzyme activities in milk were positively correlated with those in blood and with blood NEFA, BHB and TBil levels, and negatively correlated with blood glucose, TChol and TG. A significant positive correlation existed between blood and milk BHB values. Many correlations showed the same slope during all lactation periods. In conclusion, similar changes in blood and milk metabolite concentration during lactation and milk to blood correlations confirm that milk has great potential in predicting of blood metabolites and metabolic status of cows. Full article

Mammalian INDY (mINDY, NaCT, gene symbol SLC13A5) is a potential target for the treatment of metabolically associated fatty liver disease (MAFLD). This study evaluated the effects of a selective, cross-species active, non-competitive, non-substrate-like inhibitor of NaCT. First, the small molecule inhibitor ETG-5773 was evaluated for citrate and succinate uptake and fatty acid synthesis in cell lines expressing both human NaCT and mouse Nact. Once its suitability was established, the inhibitor was evaluated in a diet-induced obesity (DIO) mouse model. DIO mice treated with 15 mg/kg compound ETG-5773 twice daily for 28 days had reduced body weight, fasting blood glucose, and insulin, and improved glucose tolerance. Liver triglycerides were significantly reduced, and body composition was improved by reducing fat mass, supported by a significant reduction in the expression of genes for lipogenesis such as SREBF1 and SCD1. Most of these effects were also evident after a seven-day treatment with the same dose. Further mechanistic investigation in the seven-day study showed increased plasma β-hydroxybutyrate and activated hepatic adenosine monophosphate-activated protein kinase (AMPK), reflecting findings from Indy (−/−) knockout mice. These results suggest that the inhibitor ETG-5773 blocked citrate uptake mediated by mouse and human NaCT to reduce liver steatosis and body fat and improve glucose regulation, proving the concept of NaCT inhibition as a future liver treatment for MAFLD. Full article

Betaine (BET) supplementation decreases homocysteine concentration in plasma, but it may also have an adverse effect on health by increasing blood lipid concentrations, at least in overweight and obese individuals. The aim of this study was to evaluate the effect of BET supplementation on the lipid profile and concentrations of homocysteine, inflammatory cytokines, and liver enzymes in physically active, healthy males. This was a randomized, placebo (PL)-controlled, double-blinded, crossover trial. BET (2.5 or 5.0 g/d) was administered for 21 days. Before and after supplementation with BET or PL, anthropometric measurements and blood were collected in a fasted state. Our results show that BET supplementation significantly decreased homocysteine concentration (from 17.1 ± 4.0 μmol/L before BET to 15.6 ± 3.5 μmol/L after BET, p = 0.009, η² = 0.164). However, the intervention had no effect on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triacylglycerol, interleukins 1β and 6, and tumour necrosis factor α concentrations, or alanine and aspartate activities. In addition, there were no interactions between the MTHFR genotype and BET dose. In conclusion, BET supplementation may be beneficial for homocysteine concentration in healthy, physically active males, with no detrimental effect on lipid profile. Full article

The gut microbiota has become a significant factor associated with health and disease. Although many studies have reported the implications of changes in the gut microbiota on cardiovascular diseases, there are no reports on the relationship between heart rate variability (HRV) and the gut microbiota. Therefore, we investigated the association between gut microbiota abundance and HRV parameters in this cross-sectional study of the general Japanese population. This study included 950 participants of the Iwaki Health Promotion Project who underwent a medical examination in 2019 that included HRV and gut microbiota measurements. At the genus level, multivariate regression analysis showed that higher gut microbial diversity was associated with a higher standard deviation of RR intervals (SDNN). Moreover, a higher SDNN was associated with a higher relative count of Lachnospiraceae incertae sedis. L. incertae sedis abundance was associated with higher HRV parameters such as SDNN, coefficient of variation of RR intervals, low-frequency component power (LF)/high-frequency component power, and LF. In the general Japanese population, higher gut microbial diversity and L. incertae sedis abundance were associated with higher HRV parameters. Full article

Calcium (Ca) and phosphorus (P) homeostasis is maintained by several regulators, including vitamin D and fibroblast growth factor 23 (FGF23), and their tissue-specific activation and signaling cascades. In this study, the tissue-wide expression of key genes linked to vitamin D metabolism (CYP2R1, CYP27A1, CYP27B1, CYP24A1, GC, VDR) and FGF23 signaling (FGF23, FGFR1-4, KL) were investigated in pigs fed conventional (trial 1) and divergent P diets (trial 2). The tissue set comprised kidney, liver, bone, lung, aorta, and gastrointestinal tract sections. Expression patterns revealed that non-renal tissues and cells (NRTC) express genes to form active vitamin D [1,25(OH)₂D₃] according to site-specific requirements. A low P diet resulted in higher serum calcitriol and increased CYP24A1 expression in the small intestine, indicating local suppression of vitamin D signaling. A high P diet prompted increased mRNA abundances of CYP27B1 for local vitamin D synthesis, specifically in bone. For FGF23 signaling, analyses revealed ubiquitous expression of FGFR1-4, whereas KL was expressed in a tissue-specific manner. Dietary P supply did not affect skeletal FGF23; however, FGFR4 and KL showed increased expression in bone at high P supply, suggesting regulation to balance mineralization. Specific NRTC responses influence vitamin D metabolism and P homeostasis, which should be considered for a thrifty but healthy P supply. Full article

Cardoon (C. cardunculus var. altilis DC) is commonly cultivated in the Mediterranean area to produce stalks that are consumed once cooked. Before cooking, stalks are usually subjected to blanching, which means they are exposed to darkness for a few weeks. The present work analyzed the effect of field blanching carried out for 40 days in different ways (burying the stalks under soil or covering them with plastic sheet) on the total phenolic content (TPC), phenolic profile, cynaropicrin content (a bitter compound), and antioxidant activity (AA) of two cardoon cultivars. The nutraceutical quality of blanched cardoons was also investigated following boiling. The phenolic profile revealed a higher number of compounds in blanched stalks than in raw ones. The cynaropicrin content decreased in both cultivars after blanching, indicating a sensitivity to dark conditions and the effectiveness of blanching method in reducing its bitterness. The data presented contribute to improving the knowledge about the effect of blanching and boiling on the quality of cardoon stalks. Full article

Fusarium head blight (FHB) is a serious wheat disease caused by Fusarium graminearum (Fg) Schwabe. FHB can cause huge loss in wheat yield. In addition, trichothecene mycotoxins produced by Fg are harmful to the environment and humans. In our previous study, we obtained two mutants TPS1⁻ and TPS2⁻. Neither of these mutants could synthesize trehalose, and they produced fewer mycotoxins. To understand the complex interaction between Fg and wheat, we systematically analyzed the metabolic responses of FHB-susceptible and -resistant wheat to ddH₂O, the TPS⁻ mutants and wild type (WT) using NMR combined with multivariate analysis. More than 40 metabolites were identified in wheat extracts including sugars, amino acids, organic acids, choline metabolites and other metabolites. When infected by Fg, FHB-resistant and -susceptible wheat plants showed different metabolic responses. For FHB-resistant wheat, there were clear metabolic differences between inoculation with mutants (TPS1⁻/TPS2⁻) and with ddH₂O/WT. For the susceptible wheat, there were obvious metabolic differences between inoculation with mutant (TPS1⁻/TPS2⁻) and inoculation with ddH₂O; however, there were no significant metabolic differences between inoculation with TPS⁻ mutants and with WT. Specifically, compared with ddH₂O, resistant wheat increased the levels of Phe, p-hydroxy cinnamic acid (p-HCA), and chlorogenic acid in response to TPS⁻ mutants; however, susceptible wheat did not. Shikimate-mediated secondary metabolism was activated in the FHB-resistant wheat to inhibit the growth of Fg and reduce the production of mycotoxins. These results can be helpful for the development of FHB-resistant wheat varieties, although the molecular relationship between the trehalose biosynthetic pathway in Fg and shikimate-mediated secondary metabolism in wheat remains to be further studied. Full article

Metabolic syndrome (MetS) is a clustering of at least three of the following five medical conditions: abdominal obesity, high blood pressure, high blood sugar, high serum triglycerides, and low serum high-density lipoprotein (HDL). Antipsychotic (AP)-induced MetS (AIMetS) is the most common adverse drug reaction (ADR) of psychiatric pharmacotherapy. Herein, we review the results of studies of blood (serum and plasma) and urinary biomarkers as predictors of AIMetS in patients with schizophrenia (Sch). We reviewed 1440 studies examining 38 blood and 19 urinary metabolic biomarkers, including urinary indicators involved in the development of AIMetS. Among the results, only positive associations were revealed. However, at present, it should be recognized that there is no consensus on the role of any particular urinary biomarker of AIMetS. Evaluation of urinary biomarkers of the development of MetS and AIMetS, as one of the most common concomitant pathological conditions in the treatment of patients with psychiatric disorders, may provide a key to the development of strategies for personalized prevention and treatment of the condition, which is considered a complication of AP therapy for Sch in clinical practice. Full article

Diabetic retinopathy (DR) is a leading complication in type 1 and type 2 diabetes and has emerged as a significant health problem. Currently, there are no effective therapeutic strategies owing to its inconspicuous early lesions and complex pathological mechanisms. Therefore, the mechanism of molecular pathogenesis requires further elucidation to identify potential targets that can aid in the prevention of DR. As a type of protein translational modification, O-linked β-N-acetylglucosamine (O-GlcNAc) modification is involved in many diseases, and increasing evidence suggests that dysregulated O-GlcNAc modification is associated with DR. The present review discusses O-GlcNAc modification and its molecular mechanisms involved in DR. O-GlcNAc modification might represent a novel alternative therapeutic target for DR in the future. Full article

Medulloblastoma (MB) is the most common pediatric malignant central nervous system tumor. Overall survival in MB depends on treatment tuning. There is aneed for biomarkers of residual disease and recurrence. We analyzed the proteome of waste cerebrospinal fluid (CSF) from extraventricular drainage (EVD) from six children bearing various subtypes of MB and six controls needing EVD insertion for unrelated causes. Samples included total CSF, microvesicles, exosomes, and proteins captured by combinatorial peptide ligand library (CPLL). Liquid chromatography-coupled tandem mass spectrometry proteomics identified 3560 proteins in CSF from control and MB patients, 2412 (67.7%) of which were overlapping, and 346 (9.7%) and 805 (22.6%) were exclusive. Multidimensional scaling analysis discriminated samples. The weighted gene co-expression network analysis (WGCNA) identified those modules functionally associated with the samples. A ranked core of 192 proteins allowed distinguishing between control and MB samples. Machine learning highlighted long-chain fatty acid transport protein 4 (SLC27A4) and laminin B-type (LMNB1) as proteins that maximized the discrimination between control and MB samples. Machine learning WGCNA and support vector machine learning were able to distinguish between MB versus non-tumor/hemorrhagic controls. The two potential protein biomarkers for the discrimination between control and MB may guide therapy and predict recurrences, improving the MB patients’ quality of life. Full article

Quantitative analysis of bile acids in human feces can potentially help to better understand the influence of the gut microbiome and diet on human health. Feces is a highly heterogeneous sample matrix, mainly consisting of water and indigestible solid material (as plant fibers) that show high inter-individual variability. To compare bile acid concentrations among different individuals, a reliable normalization approach is needed. Here, we compared the impact of three normalization approaches, namely sample wet weight, dry weight, and protein concentration, on the absolute concentrations of fecal bile acids. Bile acid concentrations were determined in 70 feces samples from healthy humans. Our data show that bile acid concentrations normalized by the three different approaches are substantially different for each individual sample. Fecal bile acid concentrations normalized by wet weight show the narrowest distribution. Therefore, our analysis will provide the basis for the selection of a suitable normalization approach for the quantitative analysis of bile acids in feces. Full article

We determined whether metabolic syndrome (MetS) and the increasing number of its components influenced the resting energy expenditure (REE). Data on adult men (n = 72, 40%) and women (n = 108, 60%) from European (n = 154, 86%) and Sub-Saharan African (n = 26, 14%) ancestry were used. Ninety-five (53%) participants had MetS (MetS+), while 85 (47%) were without MetS (MetS−). REE was determined through indirect calorimetry, body composition by DEXA, and clinical biochemistry by standard laboratory techniques. MetS+ had a significantly higher REE (mean ± se: MetS+: 5995 ± 87.3 vs. MetS−: 5760 ± 86.3 kJ/d, p = 0.025) when adjusted for age, gender, fat mass (FM), fat-free mass (FFM), ethnicity, season, 25OHD, insulin sensitivity, and time of data collection. Within each MetS status group, an increase in the number of components (C) resulted in a stepwise increase in REE. Relative to zero components, those with 1C had adjusted REE higher by +526 ± 248.1 kJ/d (p = 0.037), while 2C were higher than 1C by +298 ± 140.8 kJ/d (p = 0.037). Similarly, relative to 3C, those with 4C had REE higher by +242 ± 120.7 kJ/d (p = 0.049). The higher REE of 5C over 4C by 132 ± 174.5 kJ/d did not achieve statistical significance. MetS was associated with a significantly higher REE. This greater energetic cost varied directly with the numbers of its components but was most evident in those not diagnosed with the syndrome. Full article

Prostaglandins (PGD₂, PGE₂, PGF_2α), prostacyclin (PGI₂), and thromboxane A₂ (TXA₂) together form the prostanoid family of lipid mediators. As autacoids, these five primary prostanoids propagate intercellular signals and are involved in many physiological processes. Furthermore, alterations in their biosynthesis accompany a wide range of pathological conditions, which leads to substantially increased local levels during disease. Primary prostanoids are chemically instable and rapidly metabolized. Their metabolites are more stable, integrate the local production on a systemic level, and their analysis in various biological matrices yields valuable information under different pathological settings. Therefore, prostanoid metabolites may be used as diagnostic, predictive, or prognostic biomarkers in human disease. Although their potential as biomarkers is great and extensive research has identified major prostanoid metabolites that serve as target analytes in different biofluids, the number of studies that correlate prostanoid metabolite levels to disease outcome is still limited. We review the metabolism of primary prostanoids in humans, summarize the levels of prostanoid metabolites in healthy subjects, and highlight existing biomarker studies. Since analysis of prostanoid metabolites is challenging because of ongoing metabolism and limited half-lives, an emphasis of this review lies on the reliable measurement and interpretation of obtained levels. Full article

Autism spectrum disorders (ASDs) comprise a heterogeneous group of pathological conditions, mainly of genetic origin, characterized by stereotyped behavior, such as marked impairment in verbal and nonverbal communication, social skills, and cognition. Excitatory/inhibitory (E/I) imbalances have been recorded as an etiological mechanism of ASD. Furthermore, GABA, the main inhibitory neurotransmitter in adult life, is known to be much lower in both patients and rodent models of ASD. We propose correcting GABA signaling as a therapeutic strategy for ASD. In this study, 40 young male western Albino rats, 3–4 weeks in age, weighing about 60–70 g, were used. The animals were randomly assigned into six experimental groups, each including eight rats. Group I served as the control group and was orally administered phosphate-buffered saline. Groups II and III served as rodent models of ASD and were orally administered a neurotoxic dose of propionic acid (PPA). The rats in the three therapeutic groups (IV, V, and IV) received the same doses of PPA, followed by 0.2 g/kg body weight of pure Bifidobacterium infantis, a probiotic mixture of ProtexinR, and pure Lactobacillus bulgaricus, respectively, for 3 weeks. Selected variables related to oxidative stress, glutamate excitotoxicity, and gut bacteria were measured in the six groups. Both pure and mixed Lactobacillus and Bifidobacterium were effective in ameliorating glutamate excitotoxicity as an autistic feature developed in the PPA-induced rodent model. Their therapeutic effects mostly involved the correction of oxidative stress, restoration of depleted GABA, and up-regulation of GABA receptor gene expression. Pure Bifidobacterium was the most effective, followed by the mixture of probiotics and finally lactobacillus. In conclusion, Bifidobacteria and lactobacilli can be used independently or in combination as psychobiotics to ameliorate oxidative stress and glutamate excitotoxicity as two confirmed etiological mechanisms through the gut–brain axis. Full article

Thyroid hormones (THs) play an indispensable role in skeletal development and bone remodeling. Some studies have reported associations of THs with serum osteocalcin (OC) levels, but the results are quite inconsistent and the molecular mechanism of their simultaneous or interdependent activity on bone is almost unknown. Therefore, the aim of this study was to determine the possible associations of plasma THs with plasma OC levels and the possible mediating effect of OC on the relationship between THs and bone mineral density (BMD). For this purpose, out of the initial 1981 participants, we selected healthy euthyroid participants controlled for available confounding factors that can affect thyroid function and bone metabolism (N = 694). Given our results, we could not confirm any associations of THs with plasma OC levels nor the mediating effect of OC on the relationship between THs and BMD in euthyroid population. In the group of women controlled for menopause status (N = 396), we found a significant negative association of body mass index (BMI) with OC levels (β = −0.14, p = 0.03). We also found a negative association of free triiodothyronine (fT3) (β = −0.01, p = 0.02) and age (β = −0.003, p < 0.001) with BMD, and a positive association of BMI (β = 0.004, p < 0.001) and male gender (β = 0.1, p < 0.001) with BMD. In addition, we found significantly higher plasma OC levels and lower values of BMD in postmenopausal euthyroid women compared with premenopausal euthyroid women. In our opinion, the results of previous studies suggesting an association between circulating THs and serum OC levels may be influenced by an inconsistent selection of participants and the influence of confounding factors. Full article

Non-alcoholic fatty liver disease (NAFLD) is a common manifestation of metabolic syndrome. In addition to lifestyle, endocrine hormones play a role in the dysregulation of hepatic metabolism. The most common endocrine hormones contributing to metabolic syndrome are alterations in the levels of thyroid hormones (THs, predominantly in subclinical hypothyroidism) and of sex hormones (in menopause). These hormonal changes influence hepatic lipid and glucose metabolism and may increase hepatic fat accumulation. This review compares the effects of sex hormones, THs and the respective stimulating hormones, thyroid-stimulating hormone (TSH) and follicle-stimulating hormone (FSH), on the development of hepatosteatosis. TSH and FSH may be more relevant to the dysregulation of hepatic metabolism than the peripheral hormones because metabolic changes were identified when only levels of the stimulating hormones were abnormal and the peripheral hormones were still in the reference range. Increased TSH and FSH levels appear to have additive effects on the development of NAFLD and to act independently from each other. Full article