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PubMed2024

Dissecting the anti-obesity components of ginseng: How ginseng polysaccharides and ginsenosides target gut microbiota to suppress high-fat diet-induced obesity.

INTRODUCTION: Ginseng demonstrates therapeutic potential in treating obesity, with both experimental and clinical studies suggesting its anti-obesity effects are mediated by gut microbiota. Nonetheless, the specific chemical components responsible for this effect remain largely unidentified. OBJECTIVES: This study aims to investigate the anti-obesity effects and mechanisms of ginseng polysaccharides (GP) and ginsenosides (GS), the primary chemical components of ginseng, with a focus on their impact on gut microbiota. METHODS: The impact of GP and GS on high-fat diet (HFD)-induced obesity was assessed using a mouse model. Molecular mechanisms were explored through a combination of chemical analysis, metagenomics, RT-qPCR, ELISA, and biochemical assays. RESULTS: GP or GS administration effectively prevented adiposity in HFD-fed mice, and both effects were mediated by gut microbiota. Chemical analysis revealed diverse glycosyl groups in GP and GS. Metagenomics data suggested that GP-enriched species, e.g., Bacteroides stercorirosoris and Clostridiales bacterium encoded carbohydrate-active enzymes GH35, GH43 and PL9_1, while GS-enriched Sulfurospirillum halorespirans encoded GH16_5. These enzymes facilitated the utilization of glycosyl groups in GP and GS, selectively stimulating bacterial growth and reshaping the gut microbiota. Furthermore, bacterial species enriched by GP or GS encoded specific functional genes involved in short-chain fatty acid (SCFA) synthesis (K00625 and K00925 for GP; K18118, K00100, and K18122 for GS) and intestinal gluconeogenesis (IGN) (K01678, K00024, and K01596 for GP; K18118 and K00278 for GS). Consequently, the SCFA-GLP-1/PYY signaling and IGN were activated by both GP and GS to ameliorate obesity phenotypes. CONCLUSION: GP and GS, containing diverse glycosyl groups, selectively stimulate specific gut bacteria, triggering mechanisms involved in SCFA-GLP-1/PYY signaling and IGN activation to reduce adiposity in HFD-fed mice. The study enhances understanding of the chemical components crucial for the gut microbiota-mediated anti-obesity effect of ginseng. The mechanistic understanding provides valuable insights for developing ginseng-based drugs or health products to combat obesity.

Gastrointestinal Microbiome↗

PubMed2025

Potential biomarkers for human Ascending aortic aneurysm identified through metagenomic and metabolomic analyses: A case-control study.

INTRODUCTION: Ascending aortic aneurysm (AsAA) is a high-risk cardiovascular condition; recent research indicates a possible association between gut microbiota, plasma metabolites, and the pathogenesis of AsAA. OBJECTIVE: This study aims to investigate the compositional and metabolic alterations in the gut microbiota of AsAA patients to identify potential biomarkers for AsAA. METHODS: This study enlisted 72 participants, comprising 44 individuals with AsAA and 28 healthy controls. All participants underwent examination for clinical features, and fecal and plasma samples were obtained for metagenomic and metabolomic studies. RESULTS: Metagenomic analysis revealed a significant reduction of 23 bacterial species in AsAA patients, including Bifidobacterium adolescentis, Bifidobacterium longum, Lactiplantibacillus plantarum, Enterococcus faecalis, and Streptococcus thermophilus, while 52 bacterial species, such as Prevotella copri, Phascolarctobacterium faecium, and Eubacterium ventriosum, were found to be enriched. Furthermore, we identified seven microbial co-abundance groups (CAGs), of which three (predominantly comprising Roseburia, Agathobacter, and Prevotella) were significantly elevated in AsAA patients, whereas one (predominantly comprising Escherichia) was substantially diminished. KEGG pathway enrichment analysis indicated that the biosynthesis of unsaturated fatty acids pathway displayed the most pronounced differences between groups. Metabolomics data revealed that 22 metabolites, including ceramides, were significantly elevated, while 8 metabolites, such as threonine, were notably downregulated. Moreover, clinical indicators like C-reactive protein (CRP) and complement components C3 and C4 have shown strong correlations with specific gut microbiota (Streptococcus, Prevotella) and plasma metabolites (threonine, ceramides). These findings indicate that inflammatory responses, metabolic dysregulation, and gut microbiota imbalance are pivotal in the etiology of AsAA. CONCLUSION: This study demonstrates substantial alterations in gut microbiota composition and plasma metabolites in patients with AsAA. Prevotella and ceramides exhibit potential as biomarkers for AsAA diagnosis. Furthermore, a synergy of Prevotella and ceramides may function as a potent disease prediction classifier, offering novel perspectives on the early diagnosis and targeted treatment of AsAA.

Humans↗

PubMed2025

Parabacteroides goldsteinii mitigates parkinsonism in LRRK2 mutant mice by reducing neuroinflammation through Gut-Brain axis.

INTRODUCTION: Alterations in the gut microbiota accompanied by intestinal inflammation are early features of Parkinson's disease (PD). Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene represent a common genetic risk factor for PD and inflammatory bowel disease. Parabacteroides goldsteinii has been reported to alleviate intestinal and systemic inflammation. However, whether modulation of the gut microenvironment at early disease stage can attenuate PD progression remains unclear. OBJECTIVE: To investigate the impact of P. goldsteinii colonization prior to the onset of motor dysfunction on PD progression. METHODS: We established a germ-free PD mouse model carrying the LRRK2 G2019S mutation and administered P. goldsteinii orally at the pre-symptomatic stage to evaluate its effects on motor performance and PD-related neuropathology. Spatial and bulk RNA transcriptomic analyses of brain tissue, together with cytokine profiling, were conducted to assess central changes. To investigate gut immunomodulatory mechanisms, we performed intestinal bulk and single-cell RNA sequencing, spectral flow cytometry as well as cellular bioenergetic analyses. RESULTS: Germ-free conditions partially alleviated PD-like phenotypes in LRRK2 G2019S mice. Colonization with P. goldsteinii at 5-months of age, prior to motor symptom onset, further improved locomotor performance, reduced neuronal α-synuclein aggregations, and mitigated microglial activation and dopaminergic neurodegeneration. Neuroprotection was mediated through enhanced noncanonical neuronal IL-12 receptor-dependent neurotrophic support without activating the canonical STAT4 phosphorylation pathway, along with suppression of microglial activation and downregulation of LRRK2 kinase activity. At the intestinal level, P. goldsteinii suppressed TLR4-driven inflammation, expanded anti-inflammatory intraepithelial CD4+CD8αα+ T cells, promoted dendritic cell and macrophage differentiation, upregulated epithelial tight-junction genes, and improved mitochondrial bioenergetics in intestinal cells. CONCLUSION: P. goldsteinii colonization attenuates the progression of LRRK2-associated parkinsonism by restoring intestinal homeostasis and reducing neuroinflammation. These findings underscore the therapeutic potential of modulating the gut-immune-brain axis during the prodromal stage of PD.

Animals↗

PubMed2025

Cetobacterium somerae ZNN-1 promotes goblet cell differentiation through glutamine-mediated Notch signaling suppression.

INTRODUCTION: The gut microbiota acts as a crucial mediator in the interaction between the diet components and the host metabolism. However, the molecular mechanism by which the gut microbiota adapts to dietary components and subsequently regulates host physiological responses remains unclear. OBJECTIVES: This study aimed to investigate the response of gut microbiota to a plant-based protein diet (soybean meal, SM) and the effects of gut microbiota on host intestinal barrier function, along with the underlying mechanisms in a fish model. METHODS: Histopathological examination, and transepithelial electrical resistance test were used to evaluate the effects of Cetobacterium somerae on intestinal barrier function. Potential molecular mechanisms were validated by integrating whole-genome sequencing, microbiota composition sequencing, transcriptomics, and metabolomics, and utilizing in vitro cell models and mouse-derived organoid models. RESULTS: The results revealed that the SM diet significantly increased the abundance of Cetobacterium somerae in fish. Administration of C.somerae ZNN-1, a dominant strain isolated from the intestine of fish fed with the SM diet, enhanced the intestinal barrier function, particularly increasing the number of goblet cells in the intestine. Whole genome analysis of C. somerae ZNN-1 showed carbohydrate metabolism-associated genes were the most abundant in its metabolic modules. C.somerae ZNN-1 supplementation significantly inhibited the Notch signaling pathway in fish intestine. Metabolomics analysis revealed that administration of C.somerae ZNN-1 increased the glutamine level in fish gut. In vitro experiments demonstrated that glutamine regulated the differentiation of goblet cell by inhibiting the Notch signaling pathway in both human intestinal epithelial cell model and mouse intestinal organoid model. CONCLUSION: C. somerae served as a key bacterium adapted to soybean meal-derived carbohydrates, and it promoted goblet cell differentiation by inhibiting the Notch pathway. This study provides a new perspective for unraveling the interaction mechanisms among diet components, intestinal microbiota and host health.

Animals↗

PubMed2026

Substrate recognition and cleavage by mucin degrading O-glycopeptidases from the gut microbe Bacteroides caccae.

O-glycopeptidases are enzymes that hydrolyze the peptide bonds in glycoproteins by a mechanism that involves specific recognition of O-linked glycans on the substrate. Bacteroides caccae, an accomplished mucin degrader, is a member of the human gut microbiota with sixteen genes encoding putative O-glycopeptidases in the peptidase_M60 family. At present, the diversity of substrate selectivity in O-glycopeptidases is not well-understood, nor is the rationale behind their expansion in bacteria such as B. caccae. Here, we reveal the activity and diversity of the peptidase_M60 O-glycopeptidases encoded in the B. caccae genome. At least thirteen of the sixteen peptidase_M60 encoding genes produce active mucinolytic enzymes. Targeted functional studies by a high-throughput FRET screen combined with detailed kinetic analyses reveal that five examples in an uncharacterized clade of peptidase_M60 proteins are specifically O-glycopeptidases with different substrate selectivities despite their relatively high degree of relatedness. Structural analyses of these enzymes, including bound complexes, reveal new insight into the molecular underpinnings of O-glycopeptidase diversity. This highlights the larger context of how varied the selectivity of peptidase_M60 O-glycopeptidases can be for the glycan moiety and/or the peptide portion of the substrates, and why mucin degraders like B. caccae diversify O-glycopeptidase substrate repertoires to potentially maximize breakdown of this extraordinarily complex polymer.

Mucins↗

PubMed2026

Probiotic potential of Parabacteroides johnsonii in mitigating age-related ovarian functional decline.

The gut microbiota is increasingly recognized as a regulator of reproductive health, yet its role in ovarian aging remains unclear. Here, we combine Mendelian randomization (MR) analysis with experimental validation to investigate the causal relationship between gut microbiota and ovarian aging. MR analysis identifies four microbial taxa significantly associated with age at natural menopause. In mouse models, germ-free mice exhibit accelerated ovarian functional decline, including reduced ovarian reserve and impaired folliculogenesis. Fecal microbiota transplantation (FMT) from young donors alleviates ovarian aging phenotypes, whereas FMT from aged donors exacerbates functional decline. Metagenomic analysis reveals species-level differences between young and ovarian-aging mice, with Parabacteroides johnsonii (P. johnsonii) enriched in young mice. Administration of P. johnsonii to middle-aged mice improves ovarian reserve, reduces follicular atresia, enhances granulosa cell proliferation, and decreases systemic inflammation. These findings highlight a causal role of the gut microbiota in ovarian aging and support microbiota-targeted interventions as a potential strategy to preserve ovarian function.

Female↗

PubMed2026

Microplastics as vectors for microbial pollutants: Biofilm-associated transfer of pathogens and antibiotic resistance genes in zebrafish intestine.

As composite carriers of microorganisms and pollutants, biofilm-attached microplastics (MPs) serve as potential vectors for the environmental migration and biotransmission of antibiotic resistance genes (ARGs) and pathogens. In this study, traditional polypropylene (PP) and biodegradable polylactic acid (PLA) MPs were used to investigate the interference effects of biofilms-attached MPs on gut microbiota and ARGs transmission, through a combination of laboratory biofilm cultivation, zebrafish (Danio rerio) exposure simulations, metagenomic sequencing, and metabolomic profiling. Results showed that MP biofilms likely induced gut dysbiosis and were associated with altered diversity and abundance of pathogens and ARGs. At the phylum level, Nitrospira was transferred from PP biofilms to the gut. At the genus level, 23 genera were transferred from MP biofilms, with PLA (23 genera) showing higher transfer capacity than PP (4 genera). Notably, two human pathogens, one opportunistic pathogen, and two ARGs (adeF and oqxB) were specifically transferred from PLA biofilms, highlighting the unique dissemination risk of biodegradable MPs. Mechanistically, MPs may activate mobile genetic elements (e.g., Tn916 transposon) through metabolic remodeling and quorum sensing, thereby promoting horizontal gene transfer and ARGs dissemination within the gut. Our findings highlight the potential role of MPs as carriers of microorganisms and ARGs, underscoring the biotransmission risks of antibiotic resistance caused by composite pollution.

Animals↗

PubMed2024

Integrated Multi-Omics Analyses Reveal Lipid Metabolic Signature in Osteoarthritis.

Osteoarthritis (OA) is the most common degenerative joint disease and the second leading cause of disability worldwide. Single-omics analyses are far from elucidating the complex mechanisms of lipid metabolic dysfunction in OA. This study identified a shared lipid metabolic signature of OA by integrating metabolomics, single-cell and bulk RNA-seq, as well as metagenomics. Compared to the normal counterparts, cartilagesin OA patients exhibited significant depletion of homeostatic chondrocytes (HomCs) (P = 0.03) and showed lipid metabolic disorders in linoleic acid metabolism and glycerophospholipid metabolism which was consistent with our findings obtained from plasma metabolomics. Through high-dimensional weighted gene co-expression network analysis (hdWGCNA), weidentified PLA2G2A as a hub gene associated with lipid metabolic disorders in HomCs. And an OA-associated subtype of HomCs, namely HomC1 (marked by PLA2G2A, MT-CO1, MT-CO2, and MT-CO3) was identified, which also exhibited abnormal activation of lipid metabolic pathways. This suggests the involvement of HomC1 in OA progression through the shared lipid metabolism aberrancies, which were further validated via bulk RNA-Seq analysis. Metagenomic profiling identified specific gut microbial species significantly associated with the key lipid metabolism disorders, including Bacteroides uniformis (P < 0.001, R = -0.52), Klebsiella pneumonia (P = 0.003, R = 0.42), Intestinibacter_bartlettii (P = 0.009, R = 0.38), and Streptococcus anginosus (P = 0.009, R = 0.38). By integrating the multi-omics features, a random forest diagnostic model with outstanding performance was developed (AUC = 0.97). In summary, this study deciphered the crucial role of a integrated lipid metabolic signature in OA pathogenesis, and established a regulatory axis of gut microbiota-metabolites-cell-gene, providing new insights into the gut-joint axis and precision therapy for OA.

Humans↗

PubMed2025

Investigation of associations between the neonatal gut microbiota and severe viral lower respiratory tract infections in the first 2 years of life: a birth cohort study with metagenomics.

BACKGROUND: Early-life gut microbiota affects immune system development, including the lung immune response (gut-lung axis). We aimed to investigate whether gut microbiota composition in neonates in the first week of life is associated with hospital admissions for viral lower respiratory tract infections (vLRTIs). METHODS: The Baby Biome Study (BBS) is a prospective birth cohort, which enrolled mother-baby pairs between Jan 1, 2016, and Dec 31, 2017, at three UK hospitals. In the present study, we only included BBS babies with a sequenced first-week stool sample and successful data linkage. Stool was collected in the first week of life for shotgun-metagenomic sequencing. We examined the following microbiota features: alpha diversity (Chao1, Shannon, and Simpson indices) and community structures (cluster-partitioning against medoids method). The participants were followed up through linkage to the Hospital Episode Statistics-Admitted Patient Care (HES-APC) database to determine vLRTI hospital admission incidence in the first 2 years of life. We used Poisson mixed-effects models for univariable and multivariable analyses to evaluate the association between microbiota features and vLRTI hospital admission incidence, adjusting for confounders identified through direct acyclic graphs. FINDINGS: 3305 (95%) of the 3476 BBS-enrolled babies for whom consent to data linkage was obtained were included in the present study. 1111 (34%) babies had a first-week sequenced stool sample, of whom 1082 (97%; 564 born vaginally and 518 born by caesarean section) were successfully linked to HES-APC, and had median follow-up of 2·0 years (IQR 1·4-2·9). Most babies were born at term (996 [92%] ≥37 weeks gestational age and 1070 [99%] >35 weeks gestational age) and healthy (1050 [97%] had no comorbidities), and 520 (48%) were female and 562 (52%) were male. Higher first-week gut microbiota alpha diversity was associated with reduced rates of vLRTI hospital admission (Chao1 Index adjusted hazard ratio [HR] 0·92 [95% CI 0·85-0·99]; Shannon Index adjusted HR 0·57 [0·33-0·98]; and Simpson Index adjusted HR 0·36 [0·11-1·20]). Three microbiota clusters were identified. Cluster 1 had a mixed composition and cluster 2 was dominated by Bifidobacterium breve, with both clusters observed in babies born vaginally and by caesarean section. Cluster 3 was found only in vaginally born babies and was dominated by Bifidobacterium longum. Having cluster 1 (mixed) or cluster 2 (B breve dominated) was independently associated with increased rates of vLRTI hospital admission compared with cluster 3 (B longum dominated; cluster 1 [mixed] 3·05 [1·25-7·41] and cluster 2 [B breve dominated] 2·80 [1·06-7·44]). INTERPRETATION: We report observational evidence that first-week gut microbiota differences are associated with clinically severe vLRTI in young children. This study identified bacterial species that could be of interest for vLRTI prevention. This finding has important implications for the design of future research and intervention strategies. FUNDING: The Wellcome Trust and Wellcome Sanger Institute core funding.

Humans↗

PubMed2024

metaExpertPro: A Computational Workflow for Metaproteomics Spectral Library Construction and Data-Independent Acquisition Mass Spectrometry Data Analysis.

Analysis of large-scale data-independent acquisition mass spectrometry metaproteomics data remains a computational challenge. Here, we present a computational pipeline called metaExpertPro for metaproteomics data analysis. This pipeline encompasses spectral library generation using data-dependent acquisition MS, protein identification and quantification using data-independent acquisition mass spectrometry, functional and taxonomic annotation, as well as quantitative matrix generation for both microbiota and hosts. By integrating FragPipe and DIA-NN, metaExpertPro offers compatibility with both Orbitrap and timsTOF MS instruments. To evaluate the depth and accuracy of identification and quantification, we conducted extensive assessments using human fecal samples and benchmark tests. Performance tests conducted on human fecal samples indicated that metaExpertPro quantified an average of 45,000 peptides in a 60-min diaPASEF injection. Notably, metaExpertPro outperformed three existing software tools by characterizing a higher number of peptides and proteins. Importantly, metaExpertPro maintained a low factual false discovery rate of approximately 5% for protein groups across four benchmark tests. Applying a filter of five peptides per genus, metaExpertPro achieved relatively high accuracy (F-score = 0.67-0.90) in genus diversity and showed a high correlation (rSpearman = 0.73-0.82) between the measured and true genus relative abundance in benchmark tests. Additionally, the quantitative results at the protein, taxonomy, and function levels exhibited high reproducibility and consistency across the commonly adopted public human gut microbial protein databases IGC and UHGP. In a metaproteomic analysis of dyslipidemia patients, metaExpertPro revealed characteristic alterations in microbial functions and potential interactions between the microbiota and the host.

Proteomics↗

PubMed2024

Dissecting host-microbe interactions with modern functional genomics.

Interrogation of host-microbe interactions has long been a source of both basic discoveries and benefits to human health. Here, we review the role that functional genomics approaches have played in such efforts, with an emphasis on recent examples that have harnessed technological advances to provide mechanistic insight at increased scale and resolution. Finally, we discuss how concurrent innovations in model systems and genetic tools have afforded opportunities to interrogate additional types of host-microbe relationships, such as those in the mammalian gut. Bringing these innovations together promises many exciting discoveries ahead.

Genomics↗

PubMed2026

Lipid metabolism is a key central, systemic and gut microbial feature of the decline in rat hippocampal function during middle age.

Middle age is emerging as a turning point in brain ageing, prognostic of future cognitive health and amenable to intervention. Metabolic and proteomic differences during this period are not yet fully understood and may potentially influence functions of the hippocampus, a brain area that regulates memory and anxiety. While the gut microbiota is implicated in brain ageing, the relationship between the gut microbiota, the metabolic state, and hippocampal proteome in middle age has not been investigated. We hypothesise that peripheral metabolic or protein features are associated with hippocampal vulnerability in middle age. Therefore, young adult and middle-aged rats were assessed for behavioural, proteomic, metabolic, and gut microbiota differences. Proteomic profiling of the hippocampus revealed differential expression of proteins indicative of altered synaptic signalling. Concurrently, adult hippocampal neurogenesis was decreased in middle age. Hippocampal microglia exhibited a lipid rich, inflammatory phenotype in middle age which correlated with poorer memory performance. CSF and serum proteomic and metabolomic analyses identified dysregulated lipid-related pathways potentially contributing to hippocampal vulnerability in middle age. Furthermore, 16S rRNA sequencing revealed reduced abundance of bacteria involved in lipid metabolism regulation. However, faecal microbiota transfer from young to middle aged rats was not sufficient to robustly improve hippocampus-dependent spatial memory. Together, these findings highlight dysfunctional lipid metabolism as a key feature of middle age that may contribute to decline in hippocampal function. Given that the scope for intervention is limited during older age, targeting biomarkers involved in metabolic and lipid homeostasis may be pivotal for the development of pharmacological or lifestyle-based interventions during middle age which could ultimately delay future cognitive ageing.

Animals↗

PubMed2026

Effects of multistrain probiotic supplementation on hepatic function and anthropometric parameters in patients with metabolic dysfunction-associated steatotic liver disease: a double-blind, randomized controlled trial.

BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD) is increasingly prevalent on a global scale. The gut microbiota is integral to its pathogenesis, prompting extensive research into microbiota modulation as a potential adjunctive therapeutic strategy. AIM: The study aimed to evaluate the effect of multistrain probiotics supplementation on hepatic function in patients with MASLD in a double-blind, randomized, controlled trial. The primary outcomes were changes in Fibrosis-4 index (FIB-4) and fatty liver index (FLI). Secondary outcomes included changes in anthropometric parameters, selected biochemical markers, and other liver-related indices. METHODS: A total of 64 patients with MASLD were randomly assigned to two groups receiving either placebo (C) or a probiotic mixture (PRO) containing the following bacterial strains: 50% Lactococcus lactis Rosell-1058, 25% Lacticaseibacillus casei Rosell-215, 12.5% Lactobacillus helveticus Rosell-52, 12.5% Bifidobacterium bifidum Rosell-71 for 12 wk. RESULTS: Significant group × time interactions were observed for FIB-4 (Q = 0.007), with reduction in the PRO group and increase in the C group (-0.05 vs. 0.10; P = 0.002). No significant interaction was found for FLI (Q = 0.942). Significant group × time interactions were also observed for aspartate aminotransferase (-2.87 vs. 1.87 U/L; Q = 0.003) and APRI (-0.03 vs. 0.02; Q = 0.001), favoring the PRO group (P < 0.001 for both). No significant changes were observed in anthropometric parameters, glucose levels, or lipid profile. CONCLUSIONS: In patients with MASLD, the 12-wk probiotic supplementation had a modest but statistically significant effect on FIB-4, aspartate aminotransferase, and APRI, with no significant effect on FLI or anthropometric and metabolic parameters. These findings suggest that this probiotic formulation may have potential benefits for liver function in MASLD. However, long-term studies incorporating imaging-based and histological endpoints are required to determine the clinical significance of these findings.

Humans↗

PubMed2026

Microbial Interactions with Protein Intake and Preterm Infant Body Composition: Secondary Analysis of a Randomized Trial.

BACKGROUND: Enteral protein supplementation improves preterm infant growth and may impact body composition and the gut microbiota. OBJECTIVES: This study aimed to identify the effects of additional enteral protein supplementation on the gut microbiota and microbial and clinical drivers of body composition. METHODS: Secondary analysis of a masked randomized trial of additional enteral protein vs. standard fortification in preterm infants born at 25 to 28 weeks of gestation (NCT03586102) was conducted. Stool samples at weeks 4 and 8 underwent 16S rRNA sequencing; functional potential was predicted by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2). Body composition was measured by air-displacement plethysmography at 36 wk postmenstrual age (PMA). Least absolute shrinkage and selection operator (LASSO) regression with multivariable linear regression identified body composition predictors. RESULTS: Among 46 infants, gestational age (P = 0.16) and sex (P = 0.55) did not differ between groups. The protein group had higher week 4 Shannon diversity than standard fortification (median 1.2 vs. 0.87, P = 0.049). Week 4 Shannon diversity was positively correlated with fat-free mass z-score at 36 wk PMA (r2 = 0.34, P = 0.02). Adjusting for covariates, the protein group had higher Peptoniphilus (β = 1.6, Padj = 0.10) and lower Vibrio centered log-ratio abundance (β = -0.98, Padj = 0.10); 62 predicted metabolic pathways were lower in the protein group (false discovery rate < 0.20). In combined LASSO models, Bacillus abundance at week 4 was the strongest predictor of fat-free mass z-score (β = -0.17, P < 0.001; R2 = 0.80) and fat mass z-score (β = -0.31, P < 0.001; R2 = 0.66). CONCLUSIONS: Additional protein supplementation is associated with fat-free mass z-score and alterations to the gut microbiota. Clinical variables and microbial variables are key predictors of body composition, suggesting that nutrition, clinical factors, and the gut microbiota jointly contribute to body composition in extremely preterm infants. This study was registered at clinicaltrials.gov as NCT03586102 https://clinicaltrials.gov/study/NCT03586102 (registered in March 2020).

Humans↗

PubMed2026

Faecalibacterium prausnitzii-derived L-arginine ameliorates insomnia by inhibiting POMC-ACTH-cortisol axis.

Insomnia is associated with gut microbial dysbiosis, but the specific microbial metabolites mediating gut-brain communication remain elusive. Here, we integrate metagenomic sequencing from 171 individuals (primary insomnia, post-COVID insomnia, and controls) with functional pathway analysis and preclinical validation. We identify Faecalibacterium prausnitzii depletion and reduced L-arginine biosynthesis as consistent features in both insomnia subtypes, accompanied by elevated cortisol levels. Genomic and in vitro analyses confirm that F. prausnitzii is a key microbial contributor to L-arginine production. In a chronic mild stress mouse model, administration of either F. prausnitzii or L-arginine restores sleep duration, normalizes corticosterone levels, and reverses stress-induced gut dysbiosis. Mechanistically, L-arginine suppresses POMC gene expression and dampens adrenocorticotropic hormone (ACTH)-stimulated corticosterone release, implicating the POMC-ACTH-cortisol axis as a key target. These findings uncover a gut-brain axis driven by F. prausnitzii-derived L-arginine that modulates sleep through endocrine signaling, positioning this metabolite as a potential therapeutic avenue for insomnia.

Arginine↗

PubMed2026

Maternal secretor status and human milk oligosaccharides influence the infant gut resistome.

The infant gut resistome is established early in life and is shaped by perinatal exposures, yet the mechanisms underlying its modulation remain unclear. We combined shotgun metagenomics of fecal samples from 57 one-month-old infants and paired milk samples from 50 mothers in the MAMI cohort to investigate the influence of maternal secretor status on early-life resistome development. Longitudinal follow-up at 6 and 12 months, and also further validation in the independent Lifelines NEXT (LLNEXT) cohort, support our findings. Cesarean section (C-section) was associated with increased antibiotic resistance gene (ARG) diversity, whereas exclusive breastfeeding reduced ARG abundance and diversity. Maternal secretor status further modified resistome composition among exclusively breastfed infants. Human milk oligosaccharide profiling identified specific glycans underlying these associations, with 2'-fucosyllactose and 6'-sialyllactose showing negative correlations with distinct ARG classes. These findings identify human milk composition as a key determinant of early-life resistome assembly and a potential target for modulating antimicrobial resistance.

Humans↗

PubMed2026

A regulator of amino acid catabolism controls Acinetobacter baumannii gut colonization.

Asymptomatic gut colonization increases the risk of clinical infection and transmission by the multidrug-resistant pathogen Acinetobacter baumannii. Ornithine utilization was shown to be critical for A. baumannii competition with the resident microbiota to persist in gut colonization, but the regulatory mechanisms and cues are unknown. Here, we identify a transcriptional regulator, AstR, that specifically activates the expression of the A. baumannii ornithine utilization operon astNOP. Phylogenetic analysis suggests that AstR was co-opted from the Acinetobacter arginine utilization ast(G)CADBE locus and is specialized to regulate ornithine utilization in A. baumannii. Reporter assays showed that astN promoter expression was activated by ornithine but inhibited by glutamate and other preferred amino acids. astN promoter expression was similarly activated by incubation with fecal samples from conventional mice but not germ-free mice, suggesting AstR-dependent activation of the astN promoter responds to intermicrobial competition for amino acids. Finally, AstR was required for A. baumannii to colonize the gut in a mouse model. Together, these results suggest that pathogenic Acinetobacter species evolved AstR to regulate ornithine catabolism, which is required to compete with the microbiota during gut colonization.

Animals↗

PubMed2025

16S rRNA and Metagenomic Datasets of Gastrointestinal Microbiota in Fetal and 7-Day-Old Goat Kids.

The perinatal period (from late gestation to the neonatal stage) in ruminants is a critical phase for fetal organ maturation, where ecological succession of gastrointestinal microbial communities significantly impacts livestock production efficiency. However, research remains insufficient regarding the distribution patterns and functional annotation of microbial communities across different gastrointestinal compartments during this period. This study characterized early microbiota dynamics in Hutianshi Goats using 16S rRNA sequencing (4 fetal goats at 90 ± 10 gestational days) and metagenomics (3 7-day-old goat kids). The fetal goat group generated 852,694 valid reads, yielding 688,277 high-quality reads after chimera removal for downstream analysis. The 7-day-old goat kids group produced 1,081,588,182 final valid reads, after data processing and assembly, 8,561,345 contigs were generated. Gene prediction identified 6,095,352 genes. Multi-database annotations (NR, KEGG, CAZy, etc.) revealed functional potential and antimicrobial resistance traits. The public release of this dataset facilitates academic understanding of microbial community dynamics and host-microbe interactions during this developmental stage, providing both theoretical foundations and data resources for ruminant developmental biology and precision breeding regulation.

Animals↗