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PubMed2026

Source- and Solubility-specific Choline, Gut Microbiota, and Dyslipidemia Risk: Trimethylamine N-oxide-associated and Non-trimethylamine N-oxide-Associated Patterns in a Prospective Cohort Study.

BACKGROUND: Dietary choline, a major precursor of the gut microbial metabolite trimethylamine N-oxide (TMAO), is implicated in dyslipidemia risk; however, source- and form-specific associations and interactions with gut microbiota remain unclear. OBJECTIVES: The aim of this study was to examine longitudinal associations of source- and form-specific dietary choline with plasma TMAO and dyslipidemia and to identify gut microbiota interactions. METHODS: Using data from the China Health and Nutrition Survey (2018-2023), dietary intake was assessed via 3 consecutive 24-h recalls in this prospective cohort study. Two-level generalized linear mixed-effects models were applied in 4828 adults (mean age: 55.9 ± 12.6 y, 56.6% females) to assess choline-dyslipidemia associations. Choline-TMAO and TMAO-dyslipidemia analyses were conducted in 1091 participants free of dyslipidemia at baseline. Among 7169 adults with gut microbiome data, Least Absolute Selection and Shrinkage Operator and logistic regression identified lipid-associated gut genera; TMAO relationships were examined in a subset of 693 participants. RESULTS: Higher intakes of total [Q4 compared with Q1: odds ratio (OR) = 1.261; 95% confidence interval (CI): 1.007, 1.580], red meat-derived (OR: 1.753; 95% CI: 1.196, 2.568), and lipid-soluble choline (OR: 1.304; 95% CI: 1.047, 1.624) were associated with higher risk of elevated low-density lipoprotein cholesterol (LDL cholesterol), whereas vegetable-derived choline was inversely associated. Egg-derived and lipid-soluble choline were positively associated with plasma TMAO, which was prospectively associated with 5-y incident dyslipidemia (Q4 compared with Q1-OR: 1.620; 95% CI: 1.047, 2.509), elevated LDL cholesterol (Q3 compared with Q1-OR: 2.478; 95% CI: 1.187, 5.174), and hypertriglyceridemia (Q4 compared with Q1-OR: 1.829; 95% CI: 1.028, 3.225). Three TMAO-associated genera were identified: Lachnospiraceae and Phascolarctobacterium as pro-risk taxa and Turicibacter as protective. The adverse LDLcholesterol association of egg-derived choline was observed exclusively in Phascolarctobacterium-enriched individuals. CONCLUSIONS: Dietary choline source and solubility differentially associated with dyslipidemia risk through TMAO-associated and non-TMAO-associated patterns, with gut microbiota as key modulators.

Humans↗

PubMed2026

Causal relationships between oral-gut microbiome and bone neoplasm-related phenotypes: Insights from bidirectional Mendelian randomization.

The human oral and gut microbiota are the 4 largest microbial communities in the body and play crucial roles in maintaining homeostasis and influencing disease. Observational studies have suggested links between these microbiota and bone neoplasm-related phenotypes, but establishing causality has been challenging due to confounding factors and reverse causality. We conducted a bidirectional, 2-sample Mendelian randomization (MR) study to investigate evidence consistent with a potential causal association between the saliva and gut microbiota and various bone neoplasm-related phenotypes. Genetic instruments for saliva and gut microbiota were sourced from large genome-wide association studies. Inverse variance weighted was the primary MR method, supplemented by 4 other MR techniques. Sensitivity analyses, including MR-Egger regression, were performed to assess pleiotropy and heterogeneity. In the forward MR analysis, Veillonella parvula from the saliva microbiota was associated with a decreased risk of bone and connective tissue neoplasms (β: -0.236, 95% CI: [-0.275, -0.197], P = 8.20E-33). MR analyses identified genetically predicted associations between several microbial taxa and bone neoplasm-related phenotypes. Reverse MR analyses showed that genetic liability to bone neoplasm-related phenotypes was associated with variation in the composition of the oral (e.g., Order Bacteroidales, Rothia mucilaginosa) and gut microbiota (e.g., Class Methanobacteria, Genus Eubacterium oxidoreducens group). Sensitivity analyses confirmed the robustness of these findings, as no statistical evidence of substantial heterogeneity or directional horizontal pleiotropy was detected. This study provides genetic evidence supporting a bidirectional causal relationship between specific saliva and gut microbiota and bone neoplasm-related phenotypes. Our findings identify several microbial taxa as potential candidates for future biomarker development and therapeutic investigation in bone neoplasm-related phenotypes. However, these genetically informed associations require further mechanistic, experimental, and prospective clinical validation before clinical application.

Humans↗

PubMed2026

Characterization of age-related changes in the gut microbiome and metabolome of Kunming dogs and their associations with police performance.

BACKGROUND: Gut microbiota plays a pivotal role in regulating the host's central nervous system (CNS) activity and behavior. However, its influence on the police performance of Kunming dogs and the underlying mechanisms remain largely unexplored. This study was the first to apply multi-omics technologies to investigate the dynamic variations in gut microbiota and their metabolic profiles across different ages of Kunming dogs. Furthermore, we systematically examined the associations between these microbial alterations and police performance metrics, providing a theoretical foundation for enhancing the working capabilities of Kunming dogs through targeted modulation of intestinal microecology. RESULTS: The study showed that puppies, young dogs and adult dogs had significantly better police performance than elderly dogs, with young dogs exhibiting the highest scores. Analysis of 16S rRNA sequencing demonstrated that gut microbial diversity and stability were highest during the young dog stage, gradually declining with age. Metagenomic analysis revealed that the abundance of Lactobacillus acidophilus, Lactobacillus johnsonii, Limosilactobacillus reuteri, Ligilactobacillus animalis and Muribaculum gordoncarteri were strongly correlated with police performance. The results of metagenome-assembled genomes (MAGs) indicated that the above species have functional genes involved in GABAergic and glutamatergic synapse pathways. Furthermore, metabolomic analysis showed that differential metabolites were enriched in the neuroactive ligand-receptor interaction pathway, in which GABA (γ-aminobutyric acid), histamine and tyramine metabolites were positively correlated with the above species and police performance. CONCLUSION: The species L. acidophilus, L. johnsonii, L. reuteri, L. animalis, and M. gordoncarteri, which were enriched in the gut of puppies and young Kunming dogs, may potentially influence the nervous system through the production of neurotransmitters and neuromodulators, suggesting a possible association with police performance. Video Abstract.

Animals↗

PubMed2026

Exploring the role of gut microbiota in coronary atherosclerosis through lipoprotein-mediated cholesterol transport and distribution: A Mendelian randomization analysis.

We employed Mendelian randomization (MR) to explore causal relationships between gut microbiota (GM), coronary atherosclerotic heart disease (CAHD), and potential metabolic mediators. We utilized summary statistics from genome-wide association studies (GWAS), encompassing data on 473 GM traits from comprehensive microbiome GWAS, 61 lipoprotein-mediated cholesterol transport and distribution data from large-scale metabolic biomarker studies, and coronary atherosclerosis (CA) data from the GWAS catalog (study accession GCST90043957) involving 456,348 European participants. Bidirectional MR analyses were conducted to investigate the causal relationships between GM and CA. Two-sample Mendelian randomization analyses were performed to identify potential mediating metabolites and quantify the mediation proportion. Ultimately, the GM GCA-900066755, identified through MR as having a potential causal relationship, was selected to investigate its potential effects on CA by influencing cholesterol transport and distribution. Our results indicated that GCA-900066755 was positively associated with an increased risk of CA (odds ratio = 1.156). CA did not significantly affect the levels of GCA-900066755 (odds ratio = 1.009). GCA-900066755 was negatively correlated with total cholesterol levels in medium high-density lipoprotein, which reduced CA risk, and was positively correlated with total cholesterol levels in low-density lipoprotein (LDL), large LDL, medium LDL, and small LDL, which were positively associated with CA. Mediation analysis showed 7 data points mediating the association between GCA-900066755 and CA. Our MR study supports a causal relationship between specific GM groups and the risk of CAHD, highlighting that cholesterol traits are not merely outcomes associated with the relationship between GM and CAHD, but are important mediating factors. Understanding the biological mechanisms of these traits can provide a concrete foundation for future targeted interventions.

Mendelian Randomization Analysis↗

PubMed2026

Dynamics of gut bacteriophage in diversity outbred mice studied over lifespan and during extreme caloric restriction.

BACKGROUND: The majority of bacteria in the vertebrate gut harbor integrated bacterial viruses ("bacteriophages" or "phages"; integrated phage are termed "prophages"). To probe phage replication strategies in the mammalian gut microbiome, we investigated phage activity in a large longitudinal study of diversity outbred mice (913 animals) undergoing extreme dietary restriction with detailed phenotypic characterization across lifespan. RESULTS: We assembled 54,119 candidate DNA viral genomes from 2997 longitudinal metagenomes, forming 6462 viral operational taxonomic units (vOTUs). Over 85% of vOTUs annotated as novel. Viruses annotated predominantly as prophages in the Caudoviricetes class. We detected no eukaryotic DNA viruses, and none of the strictly lytic Crassvirales order that is abundant in human gut. The most prevalent phages had the widest predicted host ranges. The relative abundance of most phages was highly correlated to that of their inferred host bacteria, suggesting quiescent prophages dominate viral metagenomes, consistent with "piggyback-the-winner" dynamics. After accounting for close phage-bacterial covariation, we did identify a subset of phages changing in relative abundance and prevalence relative to their hosts in response to dietary restriction and aging. In particular, phages with larger genomes become less common in diets with restricted calories, potentially reflecting a higher fitness cost to their host. Generalist phages were enriched for a gene encoding a single-strand DNA binding protein which is reportedly involved in DNA repair and protection from nucleases encoded by host cells. Lytic phages became more common with aging, and we observed a reduction in phage richness with age, both findings previously observed in human cohorts. CONCLUSION: These studies enrich our understanding of DNA phage dynamics in gut while emphasizing the predominance of "piggyback-the-winner" strategies.

Animals↗

PubMed2026

Harnessing probiotics to combat nonylphenol toxicity: a multiomics approach of gut microbiome remodelling in Silurus meridionalis.

BACKGROUND: As a ubiquitous environmental endocrine disruptor, nonylphenol (NP) threatens aquatic organisms, driving the need for sustainable mitigation strategies. While probiotics represent promising eco-friendly supplements, their molecular mechanisms against NP toxicity remain unclear. In this study, S. meridionalis received 7-week of probiotic (Bacillus subtilis and Lactobacillus acidophilus) pretreatment followed by 15 days of NP exposure. Integrated metagenomics, transcriptomics, and metabolomics analyses, with Reverse transcription quantitative real-time PCR (RT‒qPCR) and Enzyme-linked immunosorbent assay (ELISA) validation, were performed to elucidate microbial, genetic and metabolic responses. Growth performance, including the specific growth rate (SGR) and weight gain rate (WGR), was concurrently assessed. RESULTS: NP exposure significantly suppressed WGR and SGR, and induced gut microbiota dysbiosis alongside and lipid metabolism disorders in S. meridionalis. Probiotic pretreatment effectively reversed these toxic effects and restored the inhibited WGR and SGR. Multiomics integration revealed that the protective effects of probiotics were mediated by a coherent "microbe-host" co-metabolism network across 3 progressive layers: (1) Microbial Remodelling: in which beneficial taxa (e.g., Bacteroides eggerthii and Cetobacterium sp.) were enriched, and the functional capacity for short-chain fatty acid (SCFA) synthesis and ethanolamine metabolism was enhanced; (2) Host Gene Regulation: in which key lipid metabolism genes (ek1, cept1, ept1, mogat2, and abcg2a) were upregulated, and lipase activity was restored; and (3) Metabolic Pathway Activation and Physiological Repair: in which the activity of the NP-suppressed Kennedy pathway was reactivated, thereby promoting phosphatidylethanolamine (PE) and phosphatidylcholine (PC) synthesis and ultimately restoring gut barrier function. These results were further were corroborated by RT‒qPCR and ELISA. CONCLUSION: This study systematically elucidated that probiotics alleviated NP toxicity by remodelling a "microbiota-host Kennedy pathway gene-metabolite (PE and PC)-growth performance" regulatory network. The key mechanism is the beneficial microbiota activating the host Kennedy pathway and restoring gut phospholipid homeostasis and barrier function. These findings provide a theoretical basis for developing targeted, lipid metabolism focused probiotic feed additives for use in sustainable aquaculture.

Probiotics↗

PubMed2025

Metagenome-Based Characterization of the Gut Virome Signatures in Patients With Gout.

The gut microbiome has been implicated in the development of autoimmune diseases, including gout. However, the role of the gut virome in gout pathogenesis remains underexplored. We employed a reference-dependent virome approach to analyze fecal metagenomic data from 102 gout patients (77 in the discovery cohort and 25 in the validation cohort) and 86 healthy controls (HCs) (63 and 23 in each cohort). A subset of gout patients in the discovery cohort provided longitudinal samples at Weeks 2, 4, and 24. Our analysis revealed significant alterations in the gut virome of gout patients, including reduced viral richness and shifts in viral family composition. Notably, Siphoviridae, Myoviridae, and Podoviridae were depleted, while Quimbyviridae, Retroviridae, and Schitoviridae were enriched in gout patients. We identified 359 viral operational taxonomic units (vOTUs) associated with gout. Enriched vOTUs in gout patients predominantly consisted of Fusobacteriaceae, Bacteroidaceae, and Selenomonadaceae phages, while control-enriched vOTUs included Ruminococcaceae, Oscillospiraceae, and Enterobacteriaceae phages. Longitudinal analysis revealed that a substantial proportion of these virome signatures remained stable over 6 months. Functional profiling highlighted the enrichment of viral auxiliary metabolic genes, suggesting potential metabolic interactions between viruses and host bacteria. Notably, gut virome signatures effectively discriminated gout patients from HCs, with high classification performance in the validation cohort. This study provides the first comprehensive characterization of the gut virome in gout, revealing its potential role in disease pathogenesis and highlighting virome-based signatures as promising biomarkers for gout diagnosis and future therapeutic strategies.

Humans↗

PubMed2025

Host clustering of Campylobacter species and enteric pathogens in a longitudinal cohort of infants, family members and livestock in rural Eastern Ethiopia.

BACKGROUND: Livestock are recognized as major reservoirs for Campylobacter species and other enteric pathogens, posing infection risks to humans. High prevalence of Campylobacter during early childhood has been linked to environmental enteric dysfunction and stunting, particularly in low-resource settings. METHODS: A total of 280 samples from Campylobacter positive households with complete metadata were analyzed by shotgun metagenomic sequencing followed by bioinformatic analysis via the CZ-ID metagenomic pipeline (Illumina mNGS Pipeline v7.1). Further statistical analyses in JMP PRO 16 explored the microbiome, emphasizing Campylobacter and other enteric pathogens. Two-way hierarchical clustering and split k-mer analysis examined host structuring, patterns of co-infections and genetic relationships. Principal component analysis was used to characterize microbiome composition across the seven sample types. RESULTS: The study identified that microbiome composition was strongly host-driven, with more than 3844 genera detected, and two principal components explaining 62% of the total variation. Twenty-one dominant (based on relative abundance) Campylobacter species showed distinct clustering patterns for humans, ruminants, and broad hosts. The broad-host cluster included the most prevalent species, C. jejuni, C. concisus, and C. coli, present across sample types and a sub-cluster within C. jejuni involving humans, chickens, and ruminants. Campylobacter species from chickens showed strong positive correlations with mothers (r = 0.76), siblings (r = 0.61) and infants (r = 0.54), while co-occurrence analysis found a higher likelihood (Pr > 0.5) of pairs such as C. jejuni with C. coli, C. concisus, and C. showae. Analysis of the top 50 most abundant microbial taxa showed a distinct cluster uniquely present in human stool and absent in all livestock. The study also found frequent co-occurrence of C. jejuni with other enteric pathogens such as Salmonella, and Shigella, particularly in human and chicken. Additionally, instances of Candidatus Campylobacter infans (C. infans) were identified co-occurring with Salmonella and Shigella species in stool samples from infants, mothers, and siblings. CONCLUSIONS: A comprehensive analysis of Campylobacter diversity in humans and livestock in a low-resource setting revealed that infants can be exposed to multiple Campylobacter species early in life. C. jejuni is the dominant species with a propensity for co-occurrence with other notable enteric bacterial pathogens, including Salmonella, and Shigella, especially among infants. Video Abstract.

Animals↗

PubMed2026

Effects of aerobic exercise on inflammation and gut microbiota in obese mice: a metagenomic and metabolomic analysis.

BACKGROUND: Aerobic exercise can ameliorate insulin resistance (IR). However, the mechanism by which aerobic exercise regulates the gut microbiome to ameliorate IR and obesity remains unexplored. METHODS: Obese models were established by feeding C57BL/6 male mice a high-fat diet. A total of 26 mice were randomly divided into control group (group A, N = 8) and high-fat diet group (HFD group, N = 18). Successfully modeled mice were further assigned to model group (group B, N = 8) and exercise group (group C, N = 8). Group C underwent a 6-week treadmill exercise program (12 m/min, 60 min per day, 5 days per week). After intervention, colon tissue morphology was observed through hematoxylin-eosin staining, serum lipids and inflammatory indicators levels were detected by ELISA. The changes in the intestinal microbiota of the mice were also examined using metagenomic sequencing and UPLC-MS non-targeted metabolomics. RESULTS: Compared with the group A, the body weight, TC, TG, LDL-C, blood glucose, insulin, and IR in the group B significantly increased (P < 0.01), while the levels of pro-inflammatory cytokines TXNIP, TNF-α, NLRP3, IL-1β, and IL-18 significantly increased (P < 0.05 or P < 0.01). Compared with the group B, aerobic exercise reduced the body weight, TC, blood glucose, insulin, IR, TXNIP, TNF-α and other indicators in obese mice (P < 0.05 or P < 0.01). Moreover, aerobic exercise can regulate the imbalance of the intestinal flora in obese mice and ameliorate the disorder of metabolites. The metabolic pathways including arachidonic acid metabolism and histidine metabolism showed the most significant differences after the intervention of aerobic exercise. CONCLUSIONS: In conclusion, aerobic exercise can ameliorate glucose and lipid metabolism, IR, inflammatory response, and regulate the intestinal microecology and metabolic disorders in obese mice. The mechanism may be closely related to enhancing the diversity of intestinal flora, regulating the metabolism of arachidonic acid and histidine.

Animals↗

PubMed2026

Exploring the hypothetical role of Bacteroides species in depression progression: insights from metagenomic analysis.

Depression, a psychiatric disorder with significant morbidity and mortality, has a complex etiology. Recent advances in microbiome research have highlighted the potential role of fecal microbiota in depression pathogenesis. This study utilized shotgun metagenomic sequencing to compare the fecal microbiota of 28 depression patients and 26 healthy individuals. Significant differences in fecal microbiota composition were observed between the two groups. We generated 350 non-redundant high-quality metagenome-assembled genomes (MAGs) by binning and conducted comparisons between the depression and control groups. Notably, we found that the MAGs enriched in people with depression mostly belonged to Bacteroides, indicating a close link between Bacteroides abundance and the development of depression, suggesting that Bacteroides might be a potential culprit for depression. In the depression group, we found that the module of nitric oxide synthesis was remarkably enriched, and all Bacteroides MAGs contained genes annotated as nitric oxide synthase, suggesting that increased levels of Bacteroides may contribute to elevated nitric oxide synthesis. A distinct microbial signature consisting of Arthrobacter sp._U41, Bacillus cereus, Campylobacter rectus, and Pasteurella dagmatis accurately discriminates between depressed individuals and healthy controls, achieving an average area under the receiver operating characteristic curve of 0.950. This research sheds light on the potential role of fecal microbiota in depression and highlights specific metabolic pathways and microbial markers for further investigation.IMPORTANCEThis research highlighted significant differences in the composition and function of fecal microbiota between individuals with depression and healthy individuals, particularly the enrichment of Bacteroides metagenome-assembled genomes (MAGs) in depression patients. The upregulation of the nitric oxide synthesis pathway associated with these MAGs belonging to Bacteroides in the gut of depression patients had also been observed. The selected bacterial biomarkers reliably differentiate depression cases from healthy controls with high diagnostic accuracy (mean area under the receiver operating characteristic curve = 0.950). Our results suggest the importance of exploring microbial markers as potential diagnostic and therapeutic targets in managing depression.

Humans↗

PubMed2026

Cross-kingdom genomic variation in chicken gut microbiomes: insights from China's diverse local breeds.

BACKGROUND: The gut microbiome possesses substantial genetic diversity that supports microbial adaptation, but the genomic variation patterns across its prokaryotic and viral populations remain incompletely characterized. RESULTS: Through integrated metagenomic and metatranscriptomic analysis of ten indigenous chicken breeds from China, we recovered 1527 representative prokaryotic MAGs, 37,555 representative DNA viral contigs, and 1867 representative RNA viral contigs (primarily comprising Bacillota/Bacteroidota, Uroviricota, and Lenarviricota/Pisuviricota, respectively). By integrating complementary short-read and long-read metagenomics with metatranscriptomics, we identified structural variants (SVs) and single-nucleotide variants (SNVs) in these cross-kingdom genomes. Positive SV-SNV density correlations occurred consistently across all microbial groups, indicating coordinated mutational processes. DNA viruses exhibited the highest variant prevalence (86.9% SNVs, 47.7% SVs), with temperate phages accumulating significantly more variants than virulent phages. Functionally, prokaryotic variants accumulated in carbohydrate metabolism and amino acid metabolism, while viral variants demonstrated broad metabolic hijacking. Horizontal gene transfer (HGT) was characterized by a strong virus-associated signature (69.40% of 536 events) and marked by an asymmetric pattern, with phage-to-bacteria (P-to-B) flow alone constituting 37.50% of all events. Random forest analysis revealed a strong bidirectional predictive relationship between SV and SNV densities across prokaryotic, DNA viral, and RNA viral populations, suggesting coupled genomic instability. Niche breadth emerged as a major driver of SNVs across kingdoms and was positively correlated with variant density. In prokaryotes, HGT events significantly shaped variant patterns. For viruses, genomic GC content was an important factor and consistently showed a negative correlation with SNV density in both DNA and RNA viruses. CONCLUSIONS: These findings demonstrate that coordinated mutational processes and kingdom-specific intrinsic factors drive genomic variation, with viruses serving as key genetic exchange vectors in chicken gut ecosystems. Video Abstract.

Animals↗

PubMed2026

Admission Gut and Plasma-Derived Signatures Associated With Severity and 90-day Outcome in Hepatitis A-Related and Drug-Induced Acute Liver Failure.

Acute liver failure (ALF) due to hepatitis A (ALF-A) has high mortality, but admission-day markers associated with disease severity and outcome are unknown. We aimed to define gut microbiome and plasma multi-omics signatures associated with severity and 90-day outcomes in ALF-A, compared to drug-induced ALF (ALF-D) as non-viral ALF group. ALF patients (aged 26 ± 9 years; 50.7% male, 49.3% female) with IgM HAV positive (ALF-A, n = 33), ALF-D (n = 38) were recruited along with acute viral hepatitis (AVH-A, n = 27) and healthy subjects (HC, n = 20). Stool bacteria profiling was done at D0; plasma cytokines, metabolites and barrier markers were analysed at D0, 3, 5, 7. Correlations with clinical severity parameters were assessed. Associations with 90-day mortality were assessed using severity-adjusted association analyses. ALF-A patients were more severe at the time of admission than ALF-D. In ALF-A, 90-day mortality was 33% versus 18.4% with increased severity scores like KCH 21% versus 10.5%, SOFA score 7.97 ± 2.89 versus 5.87 ± 2.32, SIRS 60.6% versus 18.4%, mechanical ventilation 39% versus 21%. At D0, ALF-A was enriched for lactate/ammonia/bile salt hydrolase/histamine-producing pathobionts like Enterococcus, Ruminococcus gnavus, Flavonifractor, Thomasclavelia correlating positively with severity (|r| > 0.4, p < 0.05) showing higher baseline abundance in ALF-A non-survivors (NS). At D0 in ALF-A, histamine accumulation, reduced tryptophan, butyrate metabolism inversely correlated with severity and worsened in ALF-A_NS by D7. Pro-inflammatory cytokines, IFABP2 were elevated at Day 0 in ALF-A, correlated positively with severity, and remained increased through Day 7 in ALF-A_NS. In contrast, ALF-D_NS retained commensals, showed increased fatty acid, bile acid biosynthesis with low levels of pro-inflammatory cytokines. In ALF-A, gut and plasma integrated multi-omics features were associated with disease severity, 90-day outcomes and identified candidate biomarkers for future validation.

Humans↗

PubMed2026

Lipidomic Profiling Reveals Differential Behaviors of Individual Free Fatty Acids During Altered Metabolic States in Rats.

We used lipidomic analyses to investigate how individual free fatty acids (FFAs) behave differently in metabolic states altered by diet and by antibiotic treatment (ABX) that depletes gut bacteria. Wistar rats were fed either a low-fat or high-fat purified diet, or standard chow with or without antibiotics for two weeks (n = 8-10). Blood samples were then collected before and after meals. Individual FFAs were quantified and grouped based on distinct postprandial response patterns across dietary and treatment conditions. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), key ω-3 FFAs, exhibited postprandial shifts suggestive of suppressed adipocyte lipolysis following meals. Fatty acids in the high-fat diet (HFD) elevated postprandial FFA levels, masking the meal-induced suppression of lipolysis observed with chow or low-fat diet (LFD). Some FFAs, including medium-chain saturated species, remained unaffected by meals. We further evaluated the impact of diet and ABX on baseline (pre-meal) concentrations of FFAs. Certain FFAs were altered by purified diets compared to standard chow. Notably, EPA and DHA were selectively depleted under HFD conditions, likely due to enhanced catabolic activity. In conclusion, lipidomic profiling revealed divergent behaviors among individual FFAs, reflecting distinct metabolic processes and regulatory mechanisms under altered metabolic states.

Animals↗

PubMed2025

New evidence for the protective effect of gut microbiota regulation of ferroptosis-related proteins against osteoporosis.

Osteoporosis (OP), characterized by bone degradation and increased fracture susceptibility, constitutes a significant global health burden. Recent findings implicate gut microbiota and ferroptosis in the regulation of bone metabolism; however, causal evidence for the gut microbiota's influence on OP specifically via ferroptosis regulation remains to be established. This study employed two-sample Mendelian randomization (MR) using genome-wide association study (GWAS) summary statistics to investigate these causal relationships and delineate mediating pathways.We assessed causal links between gut microbiota, ferroptosis-related proteins, and OP risk. Associations for gut microbiota abundance and ferroptosis-related proteins were derived from GWAS data and Icelandic blood-derived protein quantitative trait loci, respectively. Outcome data for OP were obtained from the FinnGen Release R12. The primary analysis utilized the inverse variance weighted (IVW) method, supplemented by sensitivity analyses to evaluate heterogeneity and horizontal pleiotropy.  MR analysis identified 33 gut microbial taxa causally associated with OP risk: 13 protective and 20 detrimental. Similarly, 34 ferroptosis-related proteins were categorized as protective (18) or detrimental (16) for OP. Mediation analysis revealed that the protective effect of Terrisporobacter othiniensis on OP is partially mediated by the ferroptosis regulator MDM4 (indirect effect β = -0.020, 95% CI: -0.068 to 0.029), accounting for 6.8% of the total effect. Sensitivity analyses showed no significant evidence of heterogeneity or horizontal pleiotropy. This study provides the first genetically validated evidence supporting a causal relationship between specific gut microbiota, ferroptosis-associated proteins, and OP susceptibility. Specifically, Terrisporobacter othiniensis demonstrates a novel protective mechanism, modulating OP risk partly through the ferroptosis regulator MDM4. These findings broaden understanding of the "gut-bone axis" and highlight the gut microbiota-ferroptosis pathway, particularly the MDM4/p53 axis, as a promising target for novel OP prevention and therapeutic strategies.

Ferroptosis↗

PubMed2026

Do Multi-Omics Approaches Improve the Diagnosis of Microbial Overgrowth Syndromes?

PURPOSE OF REVIEW: This review investigates how advances in breath testing (BT), small bowel (SB) culture, metagenomics, metatranscriptomics, transcriptomics and proteomics are reshaping the definition and diagnosis of small intestinal bacterial overgrowth (SIBO). It also discusses whether SIBO should be redefined as part of a larger group of microbial overgrowth syndromes. RECENT FINDINGS: Recent studies identify distinct hydrogen-, methane-, and hydrogen sulfide-associated overgrowth phenotypes, termed SIBO, intestinal methanogen overgrowth (IMO), and intestinal sulfide overproduction (ISO). SB sampling shows that these conditions involve different microbial patterns and functional activity, symptoms, and host responses. Quantitative shotgun metagenomics provides greater taxonomic and functional resolution than culture, while metatranscriptomics reveals active microbial pathways. On top of that, host transcriptomics and proteomics contribute to the better understanding of the predominant microbial effects in host cellular mechanisms in each of the distinct small bowel overgrowth types. SIBO has been increasingly identified as a disorder of microbial ecology and function rather than bacterial quantity alone. Integrating BT with SB sampling and multi-omics approaches may improve classification, clarify symptom mechanisms, and support a more individualized treatment, although standardized methods and further clinical validation remain necessary.

Humans↗

PubMed2026

Assessing the Safety and Probiotic Potential of Bifidobacterium longum subsp. infantis BI45: A Comprehensive Study from Genomic Analysis to Randomized Controlled Clinical Trial in Healthy Adults.

While probiotics are increasingly consumed for health benefits, comprehensive safety assessments, particularly for novel strains, are imperative. This study aimed to conduct a holistic safety and efficacy assessment of Bifidobacterium longum subsp. infantis (B. infantis) BI45, spanning genomic analysis, in vitro tests, In vivo toxicity test, and a clinical trial. The safety of B. infantis BI45 was evaluated through: (1) whole-genome sequencing for antibiotic resistance and virulence genes; (2) in vitro phenotyping (hemolysis, cytotoxicity, gastrointestinal tolerance and antibiotic susceptibility); (3) an acute oral toxicity study in mice; and (4) a randomized, double-blind, placebo-controlled clinical trial. Forty-eight healthy adults were recruited and randomly assigned to receive either B. infantis BI45 or a placebo (n = 24/group) for 8 weeks. Hematological, biochemical, immunological, and gut microbiota parameters were assessed. Genomic analysis identified no transferable antibiotic resistance or virulence genes. In vitro assays confirmed the absence of hemolytic and cytotoxic activity, alongside high gastrointestinal tolerance. Antibiotic susceptibility testing showed that B. infantis BI45 is sensitive to a range of antibiotics. No adverse effects were observed in the murine toxicity study at 2 × 10¹⁰ CFU/kg. Importantly, the clinical intervention revealed no adverse events or significant alterations in hematological, hepatic, or renal function markers in the B. infantis BI45 group, demonstrating an excellent safety profile. Furthermore, B. infantis BI45 supplementation significantly increased serum levels of immunomodulatory markers Immunoglobulin A (IgA) and antimicrobial peptide LL-37 compared to the placebo (p < 0.05) and modulated the gut microbiota by enriching beneficial short-chain fatty acid producers. The multi-tiered evidence demonstrates that B. infantis BI45 is a safe probiotic strain that does not induce adverse reactions in healthy adults. Its consumption positively modulates host immunity and the gut microbiota.Trial Registration Number: NCT06863415 (ClinicalTrials.gov).

Adult↗

PubMed2026

A Risk Score for Polycystic Ovary Syndrome Based on Meta-Analysis and Machine Learning of Gut Microbiota Signatures.

Polycystic Ovary Syndrome (PCOS) is a prevalent endocrine and metabolic disorder among reproductive-age women, in which emerging evidence suggests a substantial role played by the gut microbiota. To comprehensively evaluate gut microbiota alterations in PCOS and identify microbial biomarkers through integrated analysis, a systematic search of PubMed, Web of Science, and Embase was conducted for studies employing 16S rRNA gene sequencing of fecal samples from PCOS cohorts. Ten eligible PCOS cohorts, comprising 858 individuals, were included in the study, from which a risk score was derived using a 20-gene gut microbial signature associated with PCOS. Meta-analysis at the genus level identified that Subdoligranulum, NK4A214_group, and Collinsella significantly decreased, and Bacteroides increased in PCOS across multiple cohorts. Machine learning analysis identified a 20-genus microbial signature using the least absolute shrinkage and selection operator (LASSO) method, which was used to construct a risk score with an AUC of 0.835 in diagnosis prediction. Network analysis further identified Negativibacillus and Lachnospiraceae_UCG_010 as potential driver microbes in PCOS. The analysis in this study highlights key alterations in the gut microbiota across PCOS cohorts. The identified gut microbial signature and derived LASSO-based risk model offer novel insights and a potential tool for PCOS diagnosis.

Polycystic Ovary Syndrome↗

PubMed2025

Mendelian randomization and FinnGen analysis of the causal relationship between 473 gut microbiota species and chronic sinusitis.

OBJECTIVE: To investigate the causal associations between Gut Microbiota (GM) and Chronic Sinusitis (CRS) using Mendelian Randomization (MR). METHODS: Genome-Wide Association Study (GWAS) summary statistics for 473 GM taxa were obtained from MiBioGen consortium. CRS data (22,099 cases vs. 371,520 controls) were sourced from the FinnGen R12 cohort. Causal effects were estimated via Inverse Variance-Weighted (IVW), MR-Egger, weighted median, and Bayesian-weighted MR methods. Sensitivity analyses (heterogeneity and horizontal pleiotropy tests) were performed to validate robustness. RESULTS: IVW analysis identified 20 GM taxa significantly associated with CRS risk (p < 0.05). Of these, 7 taxa (e.g., Francisellales, Roseibacillus, Merdibacter massiliensis) exhibited risk-increasing effects, while 13 taxa (e.g., Firmicutes I, Succinivibrionaceae) showed protective effects. Sensitivity analyses confirmed the absence of significant heterogeneity (Cochran's Q p > 0.05) or pleiotropy (MR-Egger intercept p > 0.05). Bayesian-weighted MR validated 18 causal relationships (posterior probability > 95%), except for RUG420 sp900317985 and UBA7703 (non-significant). CONCLUSIONS: This MR study provides genetic evidence supporting causal roles of specific GM taxa in CRS pathogenesis. These findings highlight the gut-sinus axis as a potential therapeutic target and underscore the utility of large-scale biobanks (e.g., FinnGen) in advancing precision medicine. LEVEL OF EVIDENCE: Level 5. Mendelian Randomized (MR) studies are second only to randomized controlled trials in terms of the level of evidence.

Humans↗