Characteristics of gut microbiota and metabolic phenotype in patients with major depressive disorder based on multi-omics analysis

Lactiplantibacillus plantarum fermentation enhances the antidepressant effects of Hemerocallis citrina Baroni in chronic restraint stress mice

ETHNOPHARMACOLOGICAL RELEVANCE

Hemerocallis citrina Baroni (H. citrina), referred to as 'Forgetting Sadness Grass,' is a traditional Chinese medicine (TCM) known for its antidepressant effects. Fermentation is an ancient processing method for TCM. Whether fermentation affects the antidepressant effect of H. citrina is unknown.

AIM

In this study, we aim to evaluate the effect of fermented and unfermented H. citrina on chronic restraint stress-induced depression and the underlying mechanism.

MATERIALS AND METHODS

H. citrina was co-fermented with Lactiplantibacillus plantarum strains LZU-J-TSL-6 and LZU-J-LZ1-1 to produce fermented H. citrina (FH). Both H. citrina and FH were evaluated for effects on depression and anxiety in chronic restraint stress (CRS) mice.

RESULTS

Fermentation increased flavonoids and phenols while reducing terpenoids. Both H. citrina and FH exhibited antidepressant effects, with FH showing superior efficacy in alleviating depressive symptoms. Specifically, FH effectively alleviated weight loss, behavioral abnormalities, and hippocampal pathological damage caused by CRS, while significantly reducing serum levels of cortisol and inflammatory factors, and increasing hippocampal serotonin (5-HT) level. Moreover, FH can restore CRS-induced gut microbiota dysbiosis by promoting the colonization of beneficial microbes, such as Lactobacillus, and inhibiting the growth of harmful microbes, like Bacteroides_H. Importantly, we discovered that the antidepressant effects of FH are closely associated with substances such as L-theanine and myo-inositol, as well as with the metabolic pathways of alanine, aspartic acid, and glutamic acid.

CONCLUSION

Our findings suggest that fermentation alters the composition of active ingredients in H. citrina and enhance its role in depression. It highlights the potential therapeutic application of FH in treating depression.

Alterations of serum metabolic profile in major depressive disorder: A case-control study in the Chinese population

BACKGROUND

Major depressive disorder (MDD) is characterized by persistent depressed mood and cognitive symptoms. This study aimed to discover biomarkers for MDD, explore its pathological mechanisms, and examine the associations of the identified biomarkers with clinical and psychological variables.

AIM

To discover candidate biomarkers for MDD identification and provide insight into the pathological mechanism of MDD.

METHODS

The current study adopted a single-center cross-sectional case-control design. Serum samples were obtained from 100 individuals diagnosed with MDD and 97 healthy controls (HCs) aged between 18 to 60 years. Metabolomics was performed on an Ultimate 3000 UHPLC system coupled with Q-Exactive MS (Thermo Scientific). The online software Metaboanalyst 6.0 was used to process and analyze the acquired raw data of peak intensities from the instrument.

RESULTS

The study included 100 MDD patients and 97 HCs. Metabolomic profiling identified 35 significantly different metabolites (e.g., cortisol, sebacic acid, and L-glutamic acid). Receiver operating characteristic curve analysis highlighted 8-HETE, 10-HDoHE, cortisol, 12-HHTrE, and 10-hydroxydecanoic acid as top diagnostic biomarkers for MDD. Significant correlations were found between metabolites (e.g., some lipids, steroids, and amino acids) and clinical and psychological variables.

CONCLUSION

Our study reported metabolites (some lipids, steroids, amino acids, carnitines, and alkaloids) responsible for discriminating MDD patients and HCs. This metabolite profile may enable the development of a laboratory-based diagnostic test for MDD. The mechanisms underlying the association between psychological or clinical variables and differential metabolites deserve further exploration.

Fast urine metabolomics for the assessment of Zopiclone effects on insomnia

Insomnia is a common symptom of many diseases and is closely associated with neurodegenerative diseases. Zopiclone is one of several clinical hypnotics for treating insomnia. However, some patients are sensitive to this drug treatment, whereas others are not, and the underlying mechanisms remain unclear, causing confusion for making therapeutic regimens and prolong the course of the disease. In present work, we developed a fast urine metabolomics' method for evaluating the sensitivity of insomnia patients to Zopiclone treatment. Firstly, we extracted urine metabolome using methanol-water solutions of different ratios. Secondly, the extracts were either directly injected into LC-MS analysis or dried and resuspended using methanol-water solutions of different concentrations for LC-MS analysis. Then, the total abundance and chromatographic behaviors of urine metabolome from different extraction methods were compared with each other. The optimal extraction method is to mix 50 μl of urine with an equal volume of methanol and 150 μl of water for LC-MS analysis. Finally, the developed method was applied to a metabolomics study of urine from patients with insomnia to evaluate the effectiveness of Zopiclone in treating insomnia. The results showed that there were significant statistical differences in the levels of acylcarnitines, β-hydroxybutyrate (BHB), 4-hydroxybutyric acid (GHB), 3-hydroxyisovaleric acid, citrate, leucine, isoleucine, and valine between the sensitive and insensitive groups treated with Zopiclone. Furthermore, alterations in levels of GHB, valine, and isoleucine were closely correlated with Pittsburgh Sleep Quality Index (PSQI) scores, which may be potential biomarkers for assessing the sensitivity of insomnia patients to Zopiclone treatment, and guiding therapy adjustment.

Research Progress on the Mechanism of Bile Acids and Their Receptors in Depression

Depression, a highly prevalent mental disorder worldwide, arises from multifaceted interactions involving neurotransmitter imbalances, inflammatory responses, and gut-brain axis dysregulation. Emerging evidence highlights the pivotal role of bile acids (BAs) and their receptors, including farnesoid X receptor (FXR), Takeda G protein-coupled receptor 5 (TGR5), and liver X receptors (LXRs) in depression pathogenesis through modulation of neuroinflammation, gut microbiota homeostasis, and neural plasticity. Clinical investigations demonstrated altered BA profiles in depressed patients, characterized by decreased primary BAs (e.g., chenodeoxycholic acid (CDCA)) and elevated secondary BAs (e.g., lithocholic acid (LCA)), correlating with symptom severity. Preclinical studies revealed that BAs ameliorate depressive-like behaviors via dual mechanisms: direct CNS receptor activation and indirect gut-brain signaling, regulating neuroinflammation, oxidative stress, and BDNF/CREB pathways. However, clinical translation faces challenges including species-specific BA metabolism, receptor signaling complexity, and pharmacological barriers (e.g., limited blood-brain barrier permeability). While FXR/TGR5 agonists exhibit neuroprotective and anti-inflammatory potential, their adverse effects (pruritus, dyslipidemia) require thorough safety evaluation. Future research should integrate multiomics approaches and interdisciplinary strategies to develop personalized BA-targeted therapies, advancing novel treatment paradigms for depression.

Multi-omic analyses of the development of obesity-related depression linked to the gut microbe Anaerotruncus colihominis and its metabolite glutamate

Emerging evidence implicates gut microbiota in the pathogenesis of obesity-related depression (OD); however, the underlying molecular mechanisms remain inadequately explored. This study compared the microbial and transcriptional profiles between patients with OD and healthy individuals. The results revealed an enrichment of Anaerotruncus colihominis (A. colihominis) and glutamate metabolism-related genes in the OD group. Fecal microbiota transplantation (FMT) from patients with OD induced weight gain, compromised barrier function, and intensified depression-like behaviors in high-fat diet (HFD) mice. Microbial analysis in the mice feces corroborated the clinical findings. Single-cell RNA sequencing highlighted the pivotal role of the Efnb2-Ephb2 interaction in cell communication among colon epithelial and hippocampal neuron subtypes in OD mice. Notably, A. colihominis correlated with glutamate levels in the OD mice and patients. It produced glutamate through a glutamic acid metabolism-related DNA sequence, verified in an engineered Escherichia coli MG1655 strain. Both A. colihominis and glutamate reduced barrier proteins in colon epithelial cells and modulated cognitive proteins in neurons. Finally, A. colihominis treatment induced the Efnb2-Ephb2 interaction, exacerbating depression-like behaviors in germ-free HFD mice. Collectively, these findings reveal that A. colihominis and glutamate are potential intervention targets for OD treatment.

Gut microbiota causes depressive phenotype by modulating glycerophospholipid and sphingolipid metabolism via the gut-brain axis

Emerging evidence suggests that changes in the gut microbiota (GM) are related to prenatal depression onset, but the underlying molecular mechanisms remain obscure. This study was conducted to explore how disordered GM is involved in the onset of prenatal depression through the microbiome-gut-brain (MGB) axis. We transplanted fecal microbiota from women with and without prenatal depression into germ-free mice. Fecal metagenomic sequencing and LC-MS untargeted metabolomics analysis were performed to identify the GM composition, function, and metabolites in mice. Lipid metabolomics analysis was then used to characterize the lipid metabolism of brain tissue in mice. We found that mice transplanted with fecal microbiota from women with prenatal depression exhibited depressive-like behaviors as well as characteristic disorders of the phylum Firmicutes. Weighted Gene Correlation Network Analysis identified three microbial and one metabolic module in the gut, alongside two lipid metabolic modules in the brain, as significantly related to all depressive-like behaviors. These modules were enriched for glycerophospholipid and sphingolipid metabolism. In addition, the GM of mice with depressive-like behaviors were enriched and deficient in relevant functions and enzymes in the glycerophospholipid (mainly phosphatidylethanolamine) and sphingolipid (mainly hexosyl-ceramide) metabolic pathways, respectively. Consistently, glycerophospholipid and sphingolipid metabolites in the brains of depressive-like mice were up- and down-regulated. Increased phosphatidylethanolamine and decreased hexosyl-ceramide were significantly related to differential genera in the gut. Collectively, our findings provide a novel microbial and metabolic framework for understanding the role of the MGB axis in prenatal depression, indicating that the GM may be involved in the onset of depressive phenotypes by modulating central glycerophospholipid and sphingolipid metabolic homeostasis.

Exogenous L-fucose attenuates depression induced by chronic unpredictable stress: Implicating core fucosylation has an antidepressant potential

Core fucosylation is one of the most essential modifications of the N-glycans, catalyzed by α1,6-fucosyltransferase (Fut8), which transfers fucose from guanosine 5'-diphosphate (GDP)-fucose to the innermost N-acetylglucosamine residue of N-glycans in an α1-6 linkage. Our previous studies demonstrated that lipopolysaccharide (LPS) can induce a more robust neuroinflammatory response in Fut8 homozygous knockout (KO) (Fut8-/-) and heterozygous KO (Fut8+/-) mice contrasted to the wild-type (Fut8+/+) mice. Exogenous administration of L-fucose suppressed LPS-induced neuroinflammation. Numerous studies indicate that neuroinflammation plays a vital role in the development of depression. Here, we investigated whether core fucosylation regulates depression induced by chronic unpredictable stress (CUS), a well-established model for depression. Our results showed that Fut8+/- mice exhibited depressive-like behaviors and increased neuroinflammation earlier than Fut8+/+ mice. Administration of L-fucose significantly reduced CUS-induced depressive-like behaviors and pro-inflammatory cytokine levels in Fut8+/- mice. The L-fucose treatment produced antidepressant effects by attenuating the complex formation between gp130 and the interleukin-6 (IL-6) receptor and the JAK2/STAT3 signaling pathway. Notably, L-fucose treatment increased dendritic spine density and postsynaptic density protein 95 (PSD-95) expression, which were suppressed in CUS-induced depression. Furthermore, the effects of L-fucose on the CUS-induced depression were also observed in Fut8+/+ mice. Our results clearly demonstrate that L-fucose ameliorates neuroinflammation and synaptic defects in CUS-induced depression, implicating that core fucosylation has significant anti-neuroinflammatory activity and an antidepressant potential.

A comprehensive study on the regulation of Compound Zaoren Granules on cAMP/CREB signaling pathway and metabolic disorder in CUMS-PCPA induced insomnia rats

ETHNOPHARMACOLOGICAL RELEVANCE

Compound Zaoren Granules (CZG), an optimized herbal formulation based on the traditional Chinese medicine prescription Suanzaoren decoction, are designed specifically for insomnia treatment. However, the mechanisms underlying its efficacy in treating insomnia are not yet fully understood.

AIM OF THE STUDY

The research investigated the mechanisms of CZG's improvement in insomnia by regulating cAMP/CREB signaling pathway and metabolic profiles.

METHODS

The main components of CZG were characterized by liquid chromatography-mass spectrometry (LC-MS). Subsequently, these validated components were applied to network pharmacological analysis to predict signaling pathways associated with insomnia. We evaluated the effect of CZG on BV-2 cells in vitro. We also evaluated the behavioral indexes of CUMS combined with PCPA induced insomnia in rats. HE staining and Nissl staining were used to observe the pathological damage of hippocampus. ELISA was used to detect the levels of various neurotransmitters, orexins, HPA axis, and inflammatory factors in insomnia rats. Then we detected the expression of cAMP/CREB signaling pathway through ELISA, WB, and IHC. Finally, the metabolomics was further analyzed by using UHPLC-QTOF-MS/MS to investigate the changes in the hippocampus of insomnia rats and the possible metabolic pathways were also speculated.

RESULTS

The results of CZG in vitro experiments showed that CZG has protective and anti-inflammatory effects on LPS induced BV-2 cells. A total of 161 chemical components were identified in CZG. After conducting network pharmacology analysis through these confirmed components, we select the cAMP/CREB signaling pathway for further investigate. The behavioral research results on insomnia rats showed that CZG significantly prolonged sleep time, mitigated brain tissue pathological damage, and exhibited liver protective properties. CZG treats insomnia by regulating the content of various neurotransmitters, reducing levels of orexin, HPA axis, and inflammatory factors. It can also treat insomnia by upregulating the expression of the cAMP/CREB signaling pathway. Hippocampus metabolomics analysis identified 69 differential metabolites associated with insomnia. The metabolic pathways related to these differential metabolites have also been predicted.

CONCLUSION

These results indicate that CZG can significantly prolong sleep time. CZG is used to treat insomnia by regulating various neurotransmitters, HPA axis, inflammatory factors, cAMP/CREB signaling pathways, and metabolic disorders.

Exploration of potential biomarkers for prurigo nodularis based on plasma-metabolome analysis

Prurigo nodularis (PN) is a chronic and debilitating skin disease with severe itching that negatively impacts patients' quality of life and mental state. However, the treatment options for PN remain limited. Global metabolomics analysis can offer effective information on energy metabolism, pathogenesis and potential diagnostic biomarkers. No study on metabolomic analysis of PN has been reported. To further understand the mechanisms of PN and analyse the plasma metabolite profiles in patients with PN. Targeted-metabolome analysis of 306 metabolites in plasma from 18 patients with PN and 19 healthy controls was performed using Liquid Chromatography-tandem Mass Spectrometer analysis. We identified 31 differential metabolites. Most acylcarnitines, long-chain fatty acids, alpha-aminobutyric acid, hydroxybutyric acid and lactic acid among these metabolites were up-regulated in patients with PN; in contrast, glucaric acid, suberic acid, bile acid derivatives and most amino acids were down-regulated. Positive correlations exist between glucaric acid and itching severity and acylcarnitines and insomnia. Suberic acid and the Investigator's Global Assessment (IGA) scores correlate negatively. Metabolite variation reflects the dysregulation of energy metabolism and chronic systematic inflammation in PN. Several metabolites, such as glucaric acid, suberic acid and acylcarnitines, merit further study as potential biomarkers of disease severity in PN.

Research progress on intestinal microbiota regulating cognitive function through the gut-brain axis

The intestinal microbiota community is a fundamental component of the human body and plays a significant regulatory role in maintaining overall health and in the management disease states.The intestinal microbiota-gut-brain axis represents a vital connection in the cognitive regulation of the central nervous system by the intestinal microbiota.The impact of intestinal microbiota on cognitive function is hypothesized to manifest through both the nervous system and circulatory system. Imbalances in intestinal microbiota during the perioperative period could potentially contribute to perioperative neurocognitive dysfunction. This article concentrates on a review of existing literature to explore the potential influence of intestinal microbiota on brain and cognitive functions via the nervous and circulatory systems.Additionally, it summarizes recent findings on the impact of perioperative intestinal dysbacteriosis on perioperative neurocognitive dysfunction and suggests novel approaches for prevention and treatment of this condition.