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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↗

PubMed2025

Effects of Different Feeding Patterns on the Gut Virome of 6-Month-Old Infants.

The gut microbiome is essential for infant health, and in recent years, the impact of enteroviruses on infant health and disease has received increasing attention. The transmission of breast milk phages to the infant gastrointestinal tract contributes to the shaping of the infant gut virome, while breastfeeding regulates the colonization of the infant gut virome. In this study, we collected fecal samples from healthy infants and analyzed the distribution characteristics of infant viral communities by viral metagenomic analysis, and analyzed the differences in infant viral communities under different feeding practices. Our results indicate that the infant intestinal virome consists of phages and eukaryotic viruses. Caudovirales and Microviridae dominated the phage composition, and except for Siphoviridae, which was more predominant in the intestines of formula-fed infants, there were no significant differences in the overall abundance of other Caudovirales and Microviridae in the intestines of infants with different feeding patterns. Breastfeeding can lead to a higher diversity of infant gut viruses through vertical transmission, and a highly diverse gut virome helps maintain the maturation of the gut microbiome. This study informs the shaping of gut virome in healthy infants by breastfeeding and contributes to further research on infant gut virome characteristics and formation processes.

Humans↗

PubMed2006

Metagenomics: the role of the microbiome in cardiovascular diseases.

PURPOSE OF REVIEW: The human oral and intestinal microbiota interact with the host through poorly understood metabolic pathways. Investigation of such complex ecosystems and interactions has been difficult. In this paper, we assess the current evidence supporting the role of the microbiota as a significant determinant of cardiovascular disease risk. RECENT FINDINGS: The link between oral disease and cardiovascular disease was established about 15 years ago. The accumulated evidence supports, but does not prove a causal association between periodontal infection and cardiovascular disease and suggests some physiologically obvious connections between these pathologies, namely, inflammatory and immune responses, and hemostasis. Moreover, some studies have observed higher concentrations of total and LDL-cholesterol and triglycerides and lower concentrations of HDL-cholesterol in individuals with periodontitis before periodontal treatment. Likewise, recent reports suggest the influence of the gut microbiome in the risk of common age-related diseases such as cancer and potentially cardiovascular disease through modification of classical risk factors such as obesity, insulin resistance and plasma lipids. SUMMARY: The recognition that microorganisms may play an even more important role in maintaining human health than in generating diseases places metagenomics as one of the most relevant areas of future research. The knowledge of the hundreds of genomes that we host and their interaction with our own genome shall provide a much more complete understanding of the individual nutritional needs and may be an obligated part of future personalized healthcare approaches.

Cardiovascular Diseases↗

PubMed2025

Effects of commonly used antibiotics on children's developing gut microbiomes and resistomes in peri-urban Lima, Peru.

BACKGROUND: The effects of antibiotic use on children's gut microbiomes and resistomes are not well characterized in middle-income countries, where antibiotic consumption is exceptionally common. OBJECTIVES: We characterized the effects of antibiotics commonly used by Peruvian children (i.e. amoxicillin, azithromycin, cefalexin, trimethoprim/sulfamethoxazole) on the α-diversity, β-diversity and abundance of gut genera and antibiotic resistance genes (ARGs) from 3 to 16 months. METHODS: This study included 54 children from a prospective cohort of enteric infections in peri-urban Lima, 2016-19. Stools collected at 3, 6, 7, 9, 12 and 16 months underwent DNA extraction and short-read metagenomic sequencing. We profiled the taxonomy of stool metagenomes and assessed ARG abundance by aligning reads to the ResFinder database. We used daily surveillance data (40 662 observations) to tabulate the number of antibiotic courses consumed in the 30 days prior to stool sampling. Using linear mixed models, we examined associations of recent antibiotic use with richness, diversity and abundance of gut genera and ARGs over time. RESULTS: Each additional recent antibiotic course decreased Bifidobacterium and Dialister abundance and increased Veillonella abundance, although gut richness and diversity were not affected. Recent use of amoxicillin, azithromycin, cefalexin or trimethoprim/sulfamethoxazole, specifically, did not impact gut microbiome measures. Amoxicillin, azithromycin and trimethoprim/sulfamethoxazole significantly enriched multiple ARGs and amoxicillin use significantly increased total ARGs. CONCLUSIONS: Common antibiotics like amoxicillin and azithromycin appear to be key drivers of the paediatric gut resistome. Resistome perturbations appeared to be stronger, or persist for longer, than gut microbiome effects in this middle-income country setting.

Humans↗

PubMed2026

Human DNA levels in feces reflect gut inflammation and associate with presence of gut species in IBD patients across the age spectrum.

BACKGROUND: Feces represent a complex biological matrix that provides valuable information about intestinal physiology and gut microbial activity. Comprehensive fecal DNA sequencing is mostly utilized as a non-invasive way to profile the gut microbiome, and both clinical practice and research on inflammatory bowel diseases (IBD) would greatly benefit from accurate and non-invasive methods to monitor gut inflammation in IBD patients. In IBD, excessive immune cell recruitment and epithelial cell shedding in the gut increase the amount of human DNA in feces, making fecal DNA profiling a desirable approach to monitor gut inflammation dynamics. METHODS: We used a combination of sequencing techniques to comprehensively characterize the fecal DNA diversity in a newly established cohort of pediatric IBD patients and controls (Pediatric cohort, N = 134 children, Israel). We performed methylation-based human cell-specific profiling together with shotgun metagenomics to characterize the human and the microbial DNA content in feces, respectively. Moreover, we included a large complementary external cohort including adult IBD patients and controls (Adult cohort, N = 689 adults, the Netherlands), not only to compare microbial patterns across the age spectrum, but also to extend our findings from the methylation-based profiling to the more broadly-available quantification of human DNA in metagenomic sequencing. RESULTS: We found that neutrophil DNA dominates fecal human DNA content in IBD patients, and our measurements were highly correlated with fecal calprotectin levels. Combining neutrophil and other cell type DNA fractions in one metric was able to distinguish between remissive and active cases of IBD. Human reads percentage by metagenomics was well correlated with disease severity and species richness, which had distinct trends in CD and UC over time. We used a combination of species richness, human DNA percentage, and microbiome composition data to predict IBD and distinguish CD from UC in both adult and pediatric IBD cohorts. CONCLUSIONS: The comprehensive characterization of human and microbiome fecal DNA is a useful approach to track immune response level and investigate the interaction that the immune system has with gut microbiome richness and composition over time, enriching opportunities for better disease monitoring and thus better treatment of IBD patients. Video Abstract.

Humans↗

PubMed2025

Gut metagenome and plasma metabolome profiles in older adults suggest pyruvate metabolism as a link between sleep quality and frailty.

Poor sleep quality is associated with increased frailty in older adults, but the role of the gut microbiome in this relationship remains unclear. Here, gut metagenome and plasma metabolome were profiled in 1,225 individuals aged 62-96 years. Poor sleep quality was associated with reduced abundances of potential probiotics such as Faecalibacterium prausnitzii and elevated abundances of pathobionts. A gut microbiome sleep quality index (GMSI) was developed to quantify microbial balance related to better sleep quality; higher GMSI scores were inversely associated with frailty and related clinical traits. Pyruvate metabolism emerged as a key microbial pathway linking sleep quality to frailty, with features such as F. prausnitzii abundance and microbial pyridoxal 5'-phosphate biosynthesis implicated in this connection. These findings deepen our understanding of microbiome-metabolome pathways related to sleep quality and frailty in aging and provide a valuable resource for future longitudinal and interventional studies.

Humans↗

PubMed2025

Examining the bacterial diversity including extracellular vesicles in air and soil: implications for human health.

As the significance of human health continues to rise, the microbiome has shifted its focus from microbial composition to the functional roles it plays. In parallel, interest in ultrafine particles associated with clinically important impact has been increasing. Bacterial extracellular vesicles (BEVs), involved in systemic microbiome activity, are nano-sized spherical vesicles (20 - 100 nm in diameter) containing DNA, RNA, proteins, and lipids. They are known to be absorbed into the body potentially through air and soil, circulate in the blood, and directly impact diseases by affecting organs. Therefore, the aim of this study is to examine the biodiversity of bacteria and BEVs and predicted functional pathways. We sampled air and soil samples in Seoul, Korea and analyzed metagenomics based on 16S rRNA sequencing. At the phylum levels, Firmicutes in BEVs from soil and air were significantly higher than in bacteria, and Acidobacteria in both bacteria and BEVs from soil were significantly higher than from air (p < 0.05). The most dominant genera were Pseudomonas in bacteria from air and soil; and Escherichia-Shigella in BEVs from air and soil. In addition, Two-component system (ko02020) and ATP-binding cassette transporters (ko02010) were dominant functional pathways in both air and soil. The most functional pathways and orthologous groups were significantly different between air and soil (p < 0.05). In conclusion, human health can be affected differently depending on type of environment. Future study is necessary to have a better understanding of human health effects from environmental microbiota.

Soil Microbiology↗

PubMed2024

Metagenomic Analysis of Gut Microbiome of Persistent Pulmonary Hypertension of the Newborn.

Persistent pulmonary hypertension of the newborn (PPHN) is one of the most common diseases in the neonatal intensive care unit which severely affects neonatal survival. Gut microbes play an increasingly important role in human health, but there are rarely reported how gut microbiota contribute to PPHN. In our study, the metagenomic sequencing of feces from 12 PPHN's neonates and 8 controls were performed to expose the relation between neonatal gut microbes and PPHN disease. Firstly, we found that the abundance of Actinobacteria, Proteobacteria, Bacteroidetes were significantly increased in PPHN compared with controls, but the Firmicutes components was reduced. And some pathogenic strains (like Vibrio metschnikovii) were significantly enriched in the PPHN compared with controls. Secondly, functional annotation of genes found that PPHN up-regulated transmembrane transport, but down-regulated ribosome and ATP binding. Lastly, microbial metabolic pathway enrichment analysis indicated that some metabolic pathway in PPHN were conflicting and contradictory, showed that an abnormally increased metabolism, disturbed protein synthesis and genomic instability in the PPHN neonate. Our results contribute to understanding the changes in the species and function of gut microbiota in PPHN, thus providing a theoretical basis for the explanation and treatment of PPHN.

Gastrointestinal Microbiome↗

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↗

PubMed2024

Beyond water and soil: Air emerges as a major reservoir of human pathogens.

Assessing the risk of human pathogens in the environment is crucial for controlling the spread of diseases and safeguarding human health. However, conducting a thorough assessment of low-abundance pathogens in highly complex environmental microbial communities remains challenging. This study compiled a comprehensive catalog of 247 human-pathogenic bacterial taxa from global biosafety agencies and identified more than 78 million genome-specific markers (GSMs) from their 17,470 sequenced genomes. Subsequently, we analyzed these pathogens' types, abundance, and diversity within 474 shotgun metagenomic sequences obtained from diverse environmental sources. The results revealed that among the four habitats studied (air, water, soil, and sediment), the detection rate, diversity, and abundance of detectable pathogens in the air all exceeded those in the other three habitats. Air, sediment, and water environments exhibited identical dominant taxa, indicating that these human pathogens may have unique environmental vectors for their transmission or survival. Furthermore, we observed the impact of human activities on the environmental risk posed by these pathogens, where greater amounts of human activities significantly increased the abundance of human pathogenic bacteria, especially in water and air. These findings have remarkable implications for the environmental risk assessment of human pathogens, providing valuable insights into their presence and distribution across different habitats.

Humans↗

PubMed2016

The impact of metagenomic interplay on the mosquito redox homeostasis.

Mosquitoes are exposed to oxidative challenges throughout their life cycle. The primary challenge comes from a blood meal. The blood digestion turns the midgut into an oxidative environment, which imposes pressure not only on mosquito fecundity and other physiological traits but also on the microbiota in the midgut. During evolution, mosquitoes have developed numerous oxidative defense mechanisms to maintain redox homeostasis in the midgut. In addition to antioxidants, SOD, catalase, and glutathione system, sufficient supply of the reducing agent, NADPH, is vital for a successful defense against oxidative stress. Increasing evidence indicates that in response to oxidative stress, cells reconfigure metabolic pathways to increase the generation of NADPH through NADP-reducing networks including the pentose phosphate pathway and others. The microbial homeostasis is critical for the functional contributions to various host phenotypes. The symbiotic microbiota is regulated largely by the Duox-ROS pathway in Drosophila. In mosquitoes, Duox-ROS pathway, heme-mediated signaling, antimicrobial peptide production and C-type lectins work in concert to maintain the dynamic microbial community in the midgut. Microbial mechanisms against oxidative stress in this context are not well understood. Emerging evidence that microbial metabolites trigger host oxidative response warrants further study on the metagenomic interplay in an oxidative environment like mosquito gut ecosystem. Besides the classical Drosophila model, hematophagous insects like mosquitoes provide an alternative model system to study redox homeostasis in a symbiotic metagenomic context.

Animals↗

PubMed2024

Gut microbial genomes with paired isolates from China illustrate probiotic and cardiometabolic effects.

The gut microbiome displays genetic differences among populations, and characterization of the genomic landscape of the gut microbiome in China remains limited. Here, we present the Chinese Gut Microbial Reference (CGMR) set, comprising 101,060 high-quality metagenomic assembled genomes (MAGs) of 3,707 nonredundant species from 3,234 fecal samples across primarily rural Chinese locations, 1,376 live isolates mainly from lactic acid bacteria, and 987 novel species relative to worldwide databases. We observed region-specific coexisting MAGs and MAGs with probiotic and cardiometabolic functionalities. Preliminary mouse experiments suggest a probiotic effect of two Faecalibacillus intestinalis isolates in alleviating constipation, cardiometabolic influences of three Bacteroides fragilis_A isolates in obesity, and isolates from the genera Parabacteroides and Lactobacillus in host lipid metabolism. Our study expands the current microbial genomes with paired isolates and demonstrates potential host effects, contributing to the mechanistic understanding of host-microbe interactions.

Probiotics↗

PubMed2026

Natural products alleviate exercise-induced fatigue by modulating gut microbiota: a systematic review.

BACKGROUND: Exercise-induced fatigue critically impairs athletic performance and training quality. The gut microbiota, as a key regulator of the "gut-muscle axis," has emerged as a promising anti-fatigue target. Natural products - owing to their diverse sources, structural complexity, and favorable safety profiles - have attracted growing research interest. However, a systematic synthesis comparing their anti-fatigue effects via gut microbiota modulation across different sources is lacking. SCOPE AND APPROACH: We systematically searched PubMed, Web of Science, the Cochrane Library, and CNKI for original studies that administered natural products and concurrently assessed gut microbiota changes and anti-fatigue outcomes. Twenty-six studies (25 animal experiments and 1 human trial) were included and categorized into seven groups by source and chemical characteristics. A descriptive systematic review was conducted to identify common mechanisms and source-specific differentiations. KEY FINDINGS AND CONCLUSIONS: The enrichment of short-chain fatty acid (SCFA)-producing bacteria and the activation of the SCFA-AMPK/PGC-1α axis were shared core events across all product categories. However, source-dependent mechanistic divergences emerged: polysaccharides acted primarily as fermentable substrates with an optimal dose window; polyphenols and saponins exerted dual modulation on both microbiota and host signaling pathways; compound extracts achieved systemic synergy through functional complementation; marine- and animal-derived products exhibited unique targeting profiles and rapid action. Intestinal barrier maintenance and brain-gut axis regulation further extended the anti-fatigue repertoire. Collectively, natural products possess a solid mechanistic basis for alleviating exercise-induced fatigue via gut microbiota remodeling. The differentiated characteristics of these methods in targeting precision and pathway engagement provide a theoretical foundation for designing precision intervention strategies tailored to specific fatigue contexts.

Humans↗

PubMed2026

Contribution of a combined approach using refined enterotyping and non-negative matrix factorization (NMF) to the characterization of the gut microbiota in Tunisia, North Africa.

This pilot study aimed to assess the enhanced capabilities of a combined approach using refined enterotyping and non-negative matrix factorization (NMF) for identifying specific microbiota patterns in healthy adults in Tunisia. Shotgun metagenomic sequencing was performed on 21 stool samples. Taxonomic classification was carried out using Kraken2, followed by Bracken analysis. Enterotype (ET) assignment was performed using a publicly available, reference-based classification tool involving Fuzzy-k-means (FKM) clustering. Next, NMF was applied to identify 'enterosignatures' (ESs). The FKM approach revealed a co-dominance of Prevotella-ET (P-ET, 57%) and Firmicutes-ET (F-ET, 38%) with 41% of P-ET samples exhibiting a significant deviation from the reference enterotype center. These latter had a lower proportion of Prevotella-ES and a higher proportion of Bacteroides/Phocaeicola-, Firmicutes- and/or Bifidobacterium-enriched ESs. The F-ET samples were differentially enriched by Blautia (P = 0.007) and Vescimonas (P = 0.007). NMF revealed within this group, a candidate Firmicutes-associated ES driven by Blautia and encompassing Vescimonas, Akkermansia, and Methanobrevibacter. These findings demonstrate the combined power of refined enterotyping and NMF in characterizing gut microbiota, providing a key methodology for future large-scale research. However, our relatively small sample size limits statistical power and biological interpretation, making this study exploratory in nature. Candidate ES requires validation in larger independent datasets.

Humans↗

PubMed2024

Effectiveness of stabilization methods for the immediate and short-term preservation of bovine fecal and upper respiratory tract genomic DNA.

Previous research on stabilization methods for microbiome investigations has largely focused on human fecal samples. There are a few studies using feces from other species, but no published studies investigating preservation of samples collected from cattle. Given that microbial taxa are differentially impacted during storage it is warranted to study impacts of preservation methods on microbial communities found in samples outside of human fecal samples. Here we tested methods of preserving bovine fecal respiratory specimens for up to 2 weeks at four temperatures (room temperature, 4°C, -20°C, and -80°C) by comparing microbial diversity and community composition to samples extracted immediately after collection. Importantly, fecal specimens preserved and analyzed were technical replicates, providing a look at the effects of preservation method in the absence of biological variation. We found that preservation with the OMNIgene®•GUT kit resulted in community structure most like that of fresh samples extracted immediately, even when stored at room temperature (~20°C). Samples that were flash-frozen without added preservation solution were the next most representative of original communities, while samples preserved with ethanol were the least representative. These results contradict previous reports that ethanol is effective in preserving fecal communities and suggest for studies investigating cattle either flash-freezing of samples without preservative or preservation with OMNIgene®•GUT will yield more representative microbial communities.

Cattle↗

PubMed2026

A Computational Workflow for Prioritizing Microbial Metabolite-Associated Host Genes in Constipation-Predominant Irritable Bowel Syndrome.

No standardized computational pipeline exists for systematically prioritizing microbial metabolite-associated host genes and protein-ligand complexes from publicly available chemical, genomic, and structural databases. This article describes an eight-stage workflow that accepts a user-defined set of gut microbiota-derived metabolites and produces a ranked shortlist of candidate metabolite-associated host genes, enriched biological pathways, and structurally prioritized protein-ligand complexes for experimental follow-up. The pipeline integrates (i) chemoinformatic metabolite profiling; (ii) multi-database candidate target prediction using protein-chemical interaction and ligand-based target-prediction tool and a molecular docking program; (iii) differential gene expression analysis of publicly available transcriptomic data; (iv) target-differentially expressed gene overlap; (v) protein-protein interaction network construction and pathway enrichment; (vi) molecular docking with a molecular docking program; (vii) 200 ns molecular dynamics simulation using a molecular dynamics engine with a protein force field used for molecular dynamics simulations; and (viii) MM-PBSA binding free-energy estimation. As a worked example, nine gut microbiota-derived or microbiota-modified metabolites representing short-chain fatty acids, bile acids, tryptophan-derived metabolites, and urolithin A were processed using the public IBS-C rectal mucosal transcriptomic dataset GSE36701. The workflow ranked 17 unique predicted metabolite-associated genes that were differentially expressed in this dataset. Docking, molecular dynamics simulation, and MM-PBSA analyses structurally prioritized five metabolite-protein complexes: lithocholic acid-VDR, lithocholic acid-NR1H4/FXR, ursodeoxycholic acid-NR1H4/FXR, tryptamine-HTR2A (simulated in an explicit 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid bilayer), and urolithin A-CASP3. The protocol is designed to be adaptable to other metabolite sets, disease transcriptomic datasets, and target classes; all outputs are hypothesis-generating computational predictions that require independent transcriptomic replication, protein-level validation, and functional ligand-response assays before causal or therapeutic conclusions can be drawn.

Irritable Bowel Syndrome↗

PubMed2026

Longitudinal development of infant oral ecosystem: salivary metabolomic, bacteriome, and virome dynamics in early infancy.

This prospective cohort study investigated the longitudinal development of the salivary bacteriome, virome, and metabolome during early infancy. We assessed the associations between oral bacteria, viruses, and metabolites from 10 mother-infant dyads, with oral samples collected at 1 and 2 years of age. Forty saliva and plaque samples underwent untargeted metabolomic analysis, and infant saliva samples underwent metagenomic sequencing. Maternal salivary and plaque metabolomic profiles remained largely stable, whereas infant profiles were clearly separated from maternal profiles and changed with age. Notably, infant dental plaque metabolism underwent more substantial changes from year 1 to year 2 than saliva, with age-dependent metabolite shifts mainly involving energy, amino acid, nucleotide, and lipid metabolic pathways. Our findings also revealed significant developmental shifts in salivary bacteriome, virome, and functional pathway profiles during early childhood. The most abundant oral bacteria in early life, comprising over 75% of total abundance, included Veillonella, Streptococcus, Rothia, Prevotella, Neisseria, and Actinomyces species. While human viruses like Roseolovirus were detected, bacteriophages constituted the majority of the virome. Comparing infants at year 1 and year 2, we identified differentially abundant bacteria, viruses, metabolic functional pathways, and specific metabolites. We observed associations between bacteria and viruses, noting that these cross-kingdom relationships attenuated as infants grew. The study results underscore the complex and dynamic development of the oral microbiome, virome, and metabolome during early childhood.IMPORTANCEThe human oral cavity undergoes substantial microbial and metabolic development during early childhood, yet the temporal changes in the infant oral ecosystem remain incompletely understood. In this study, we longitudinally profiled the salivary metabolome, bacteriome, and virome of infants at 1 and 2 years of age. We demonstrated that the infant oral metabolome undergoes substantial developmental shifts, particularly in pathways related to energy, amino acid, and lipid metabolism; whereas maternal metabolic profiles remained stable over the same period. Furthermore, our results revealed the dynamic assembly of infant salivary virome and bacteriome and their associations with the functional pathways and metabolites. These findings provide new insights into the complex and dynamic development of the oral microbiome, virome, and metabolome in early infancy.

bacteriome↗

PubMed2026

Mechanisms linking the gut microbiota to colorectal cancer development and progression.

Colorectal cancer remains a leading cause of global cancer mortality, with a concerning rise in early-onset cases driven by complex interactions between environmental exposures, lifestyle factors, and host genetics. Mounting evidence indicates that gut microbiota dysbiosis critically modulates this oncogenic process, acting as an active participant rather than a passive bystander. This review systematically synthesizes the dichotomous roles of the intestinal microbiome in colorectal tumorigenesis through the conceptual framework of the driver-passenger model. We discuss how early initiating driver bacteria, such as Polyketide synthase-positive Escherichia coli and enterotoxigenic Bacteroides fragilis, compromise mucosal barriers, induce chronic mucosal inflammation, and inflict direct genomic instability. As the local tumor microenvironment undergoes profound metabolic remodeling, opportunistic passenger pathogens, notably Fusobacterium nucleatum, become enriched, further promoting cellular proliferation and facilitating tumor immune evasion. Conversely, protective commensals, exemplified by Clostridium butyricum and Streptococcus thermophilus, exert robust tumor-suppressive effects through multifaceted mechanisms. These beneficial microbes actively antagonize malignant progression by redirecting tumor metabolic fluxes toward oxidative stress, orchestrating deep epigenetic reprogramming, and degrading core oncoproteins to reverse chemoresistance. Transitioning from fundamental mechanisms to clinical application, we evaluate a comprehensive spectrum of microbiota-targeted interventions, encompassing non-invasive diagnostic biomarkers, fecal microbiota transplantation, engineered bacteria, phage therapy, and postbiotics. Finally, we critically address the formidable translational challenges associated with microbial heterogeneity, long-term safety, and regulatory standardization, aiming to provide a balanced perspective on integrating microbiome-based strategies into next-generation precision oncology for colorectal cancer.

Humans↗