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Trimethylamine-producing microbe Bacillus megaterium KCTC 3007 promotes antitumor immunity in endometrial cancer via type I interferon response pathways.

BACKGROUND: Endometrial cancer (ECa) is one of the most common gynecologic malignancies, with limited therapeutic responses in metastatic or recurrent cases. The bacterial microbiota has emerged as a key modulator of carcinogenesis and antitumor immunity. However, the role of endometrial microbiota in ECa pathogenesis and prognosis remains poorly understood. METHODS: We performed comprehensive multi-omics analysis integrating metatranscriptomics, transcriptomics, and targeted metabolomics from 60 ECa and 18 benign patients. RNA sequencing enabled simultaneous profiling of active tissue-resident microbiota and host gene expression. Serum metabolomics was conducted on all patients. Identified microbial-metabolite associations were validated through in vitro co-culture experiments using peripheral blood mononuclear cells (PBMCs), cancer cell lines, RNA sequencing, and live cell imaging. RESULTS: ECa patients exhibited significantly altered microbial diversity and composition compared to benign controls. Through integrated multi-omics analysis, we identified Bacillus megaterium (BM) KCTC 3007 as a beneficial microbe associated with prolonged recurrence-free survival. In an exploratory analysis of ECa subtypes, Cupriavidus taiwanensis and Marinomonas primoryensis showed potential links to poor prognosis, although these observations warrant caution due to the limited size of certain subgroups. Tissue BM abundance positively correlated with serum trimethylamine N-oxide (TMAO) levels, particularly in postmenopausal women. In vitro experiments demonstrated that BM KCTC 3007 enhanced antitumor immunity by promoting interleukin and type I interferon expression, expanding CD8 + T cell populations, and increasing immune cell-tumor cell interactions. RNA sequencing revealed activation of interferon alpha response and immune cell proliferation pathways, with IFNAR1 identified as a key upstream regulator. TMAO treatment recapitulated these immune-activating effects, enhancing CD8 + T cell responses and preferentially inducing pyroptotic cancer cell death. CONCLUSIONS: We provide the first evidence that tissue-resident BM KCTC 3007 promotes antitumor immunity in ECa through TMAO production and subsequent type I interferon-mediated immune activation. This integrated multi-omics approach establishes a complete microbe-metabolite-host mechanistic pathway and highlights the therapeutic potential of TMAO-producing probiotic strains for ECa treatment. Video Abstract.

Female

Challenges and Opportunities in Analyzing Cancer-Associated Microbiomes.

The study of cancer-associated microbiomes has gained significant attention in recent years, spurred by advances in high-throughput sequencing and metagenomic analysis. Microbiome research holds promise for identifying noninvasive biomarkers and possibly new paradigms for cancer treatment. In this review, we explore the key computational challenges and opportunities in analyzing cancer-associated microbiomes (in tumor/normal tissues and other body sites, e.g., gut, oral, and skin), focusing on sequencing-driven strategies and associated considerations for taxonomic and functional characterization. The discussion covers the strengths and limitations of current analysis tools for identifying contamination, determining compositional bias, and resolving species and strains, as well as the statistical, metabolic, and network inferences that are essential to uncover host-microbiome interactions. Several key considerations are required to guide the choice of databases used for metagenomic analysis in such studies. Recent advances in spatial and single-cell technologies have provided insights into cancer-associated microbiomes, and Artificial Intelligence-driven protein function prediction might enable rapid advances in this field. Finally, we provide a perspective on how the field can evolve to manage the ever-growing size of datasets and generate robust and testable hypotheses. This article is part of a special series: Driving Cancer Discoveries with Computational Research, Data Science, and Machine Learning/AI .

Humans

Comprehensive Assessment of the Intrinsic Pancreatic Microbiome.

OBJECTIVE: To sought comprehensively profile tissue and cyst fluid in patients with benign, precancerous, and cancerous conditions of the pancreas to characterize the intrinsic pancreatic microbiome. BACKGROUND: Small studies in pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasm (IPMN) have suggested that intrapancreatic microbial dysbiosis may drive malignant transformation. METHODS: Pancreatic samples were collected at the time of resection from 109 patients. Samples included tumor tissue (control, n = 20; IPMN, n = 20; PDAC, n = 19) and pancreatic cyst fluid (IPMN, n = 30; serous cystadenomas, n = 10; mucinous cystic neoplasm, n = 10). Assessment of bacterial DNA by quantitative polymerase chain reaction and 16S ribosomal RNA gene sequencing was performed. Downstream analyses determined the relative abundances of individual taxa between groups and compared intergroup diversity. Whole-genome sequencing data from 140 patients with PDAC in the National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium were analyzed to validate findings. RESULTS: Sequencing of pancreatic tissue yielded few microbial reads regardless of diagnosis, and analysis of pancreatic tissue showed no difference in the abundance and composition of bacterial taxa between normal pancreas, IPMN, or PDAC groups. Low-grade and high-grade dysplasia IPMN were characterized by low bacterial abundances with no difference in tissue composition and a slight increase in Pseudomonas and Sediminibacterium in high-grade dysplasia cyst fluid. Decontamination analysis using the Clinical Proteomic Tumor Analysis Consortium database confirmed a low-biomass, low-diversity intrinsic pancreatic microbiome that did not differ by pathology. CONCLUSIONS: Our analysis of the pancreatic microbiome demonstrated very low intrinsic biomass that is relatively conserved across diverse neoplastic conditions and thus unlikely to drive malignant transformation.

Humans

Immunosuppressants Rewire the Gut Microbiome-Alloimmune Axis Through Time-Dependent and Tissue-Specific Mechanisms.

BACKGROUND: Lifelong immunosuppressive therapy is required to prevent allograft rejection in organ transplantation. Current immunosuppressants effectively suppress adaptive and innate immune responses, but their broad, antigen-non-specific effects often result in severe off-target complications. It remains a significant unmet medical need in transplant medicine. RESULTS: In this study we investigated immunosuppressant effects of four major immunosuppressant classes, including tacrolimus, prednisone, mycophenolate mofetil (MMF), and fingolimod (FTY), on the gut microbiome, metabolic pathways, lymphoid architecture and lymphocyte trafficking after up to 30-day chronic exposure. Despite their distinct mechanisms of action and not designed to target the gut, all immunosuppressive drugs induced profound and time-dependent alterations in both intestine gene expression and gut microbiome composition. Progressive alterations from moderate early, drug-specific changes to a strikingly convergent microbial dysbiosis, marked by significant expansion of pathobionts of Muribaculaceae, occurred across all drug classes. Concurrently, all drugs uniformly induced significant suppression of mucosal immunity including B cell, immunoglobulin, and antigen recognition. Time-dependent changes in lymph node (LN) reorganization and cellular composition were also observed, marked by a progressive shift toward pro-inflammatory phenotypes in gut-draining mesenteric LNs and a gradual loss of tolerogenic architecture in peripheral LNs. Drug-specific metabolic alterations and distinct phases of intestinal transcriptional responses were also characterized. Notably, MMF and FTY demonstrated the most robust immunomodulatory properties, and were able to suppress alloantigen-induced inflammation through mediating regulatory T cell distribution and LN remodeling. CONCLUSIONS: Together, these findings highlight the underappreciated complexity and temporal dynamics immunosuppressants effects, particularly their impact on the gut and compartmentalized regulation of alloimmune in lymphoid tissues. Understanding these relationships offers new opportunities for refining immunosuppressive strategies to reduce treatment-related off-target complications and improve long-term organ transplant outcomes.

gut dysbiosis

Snail immunity to schistosomes: insights from omics studies.

Schistosomiasis is a serious public health concern, with transmission facilitated by a small number of freshwater snail intermediate host species. Infection outcomes vary greatly across the primary vector genera, Biomphalaria (for Schistosoma mansoni), Bulinus (for S. haematobium), and Oncomelania (for S. japonicum), even within species, ranging from full resistance to high compatibility. Omics methods have altered this field by correlating host genotype, baseline immunological status, and time-resolved responses to whether invading miracidia are eliminated or develop sporocysts. Evidence from genomes, transcriptomics, proteomics, and epigenomics suggests that resistance is frequently primed prior to exposure. However, the clearest divergence between resistant and susceptible trajectories occurs during a small early window (<12-48&#x202f;h) after penetration. During this time, recognition, hemocyte recruitment, and soluble effector deployment either come together quickly or are delayed and guided by parasite-derived modulators. Established infections cause the host to adapt to chronic conditions through immune regulation, metabolic reprogramming, tissue and neuroendocrine remodeling, microbiome modification, and parasite castration. Comparative genomics reveals that each vector genus has evolved its own immunogenomic profile, which includes lineage-specific expansions of recognition and effector gene families. Together, these findings can help with field surveillance and intervention by providing molecular compatibility markers, functional tools for testing candidate genes, and tactics that target parasite-derived immune modulators. Integrated multi-omics approaches are a top priority, yet they are still limited in snail vectors compared to other disease vector systems.

Animals

Microbial and functional shifts between flare and remission in a single-center cohort of children with inflammatory bowel disease.

BACKGROUND: Gut microbial dysbiosis is central to the pathogenesis of inflammatory bowel disease (IBD). While gut microbiome differences between patients with and without IBD are well established, microbiome changes associated with disease activity and remission remain limited, particularly in paediatric populations. AIM: To examine intra-individual taxonomic and functional gut microbiome changes during transition from active flare to remission under maintenance immunosuppression in a pilot single-center Singapore cohort of children with IBD. METHODS: Paired stool samples and clinical data were collected from seven patients with paediatric IBD [5 Crohn's disease (CD), 2 ulcerative colitis; &#x2264; 18 years] during active disease/flare (visit 1; Pediatric CD Activity Index/Pediatric Ulcerative Colitis Activity Index &#x2265; 10) and subsequent clinical remission (visit 2; Pediatric CD Activity Index/Pediatric Ulcerative Colitis Activity Index < 10). Samples underwent shotgun metagenomic sequencing for high-resolution taxonomic profiling and functional annotation of Kyoto Encyclopaedia of Genes and Genomes pathways. RESULTS: Gut microbial diversity was reduced during flare compared to remission, with Actinobacteria abundance significantly higher in remission. Two distinct microbial clusters differentiated flare and remission states: The remission cluster was enriched with Bifidobacterium adolescentis, Bifidobacterium dentium, Lactobacillus gasseri, Faecalibacterium prausnitzii, while the flare state showed increased Klebsiella pneumoniae. Remission was further characterized by a downregulation of pathogenic microbes and an upregulation of beneficial microbes including a higher abundance of the butyrate producer Anaerostipes hadrus (P = 0.046). Microbial functional genes enriched in remission were predominantly associated with metabolic pathways including vitamin and cofactor biosynthesis, as well as carbohydrate, amino acid, and lipid metabolism. CONCLUSION: The transition from flare to remission in Singaporean children with IBD is characterized by functional remodeling of the gut microbiome, which may contribute to recovery processes related to intestinal barrier integrity, cellular maintenance, and tissue repair. Targeted modulation of the gut microbiome may help sustain remission in paediatric IBD.

Functional shift

Multi-level aggregation analysis of microbiome composition and host gene expression reveals associations with systemic and local immunity.

The human gut microbiome plays a critical role in immune regulation, yet the molecular links between microbiome composition and host gene expression remain incompletely understood. We analyzed associations between host gene expression and microbiome composition in a cohort of 315 healthy individuals, integrating microarray-based gene expression data from three intestinal sites (ileum, transverse colon, and rectum) and six immune cell types with microbiome sequencing data. Using a hierarchical feature aggregation strategy combining principal component analysis, clustering, and covariate correction, we discovered significant associations primarily related to immunity. While microbial profiles were similar across the three intestinal sites, the transverse colon yielded the most "microbiome-host gene expression" associations. Among the immune cell types, CD8+ cells showed the highest number of associations. The first principal component of microbiome composition, reflecting a gradient from commensals (e.g., Ruminococcaceae and Christensenellaceae) to proinflammatory taxa ([Ruminococcus] gnavus and Lachnoclostridium), correlated with the expression of TNF-&#x3b1;-linked genes (HMOX1, CPI17, HSD3B2, and SLC5A1). Among individual genera, Catenibacterium abundance was associated with gene expression in both intestinal and immune cells, including negative associations with MRPS21 (related to mitochondrial function) in the transverse colon and with CD8+ gene programs related to T cell differentiation. These findings align with emerging evidence implicating mitochondrial dysfunction in intestinal inflammation. Our results identify multi-level associations between the gut microbiome and host gene expression, suggesting potential mechanisms by which microbiota shape local and systemic immunity and vice versa. The implicated genes and taxa represent candidates for experimental validation to improve understanding of host-microbiome homeostasis and its disruption in disease.IMPORTANCEThe gut microbiome and immune system are engaged in a complex interplay throughout human life. While most associative studies focus on case-control comparisons-typically examining patients with conditions such as inflammatory bowel disease or metabolic diseases-less is known about the molecular links between the microbiome and immune system in healthy individuals. In this study of a large cohort of healthy individuals, we addressed this gap by applying multiscale modeling to tackle the high dimensionality of host-microbiome data. We identified multi-level associations between microbiome composition and host gene expression in both intestinal tissues and immune cells. These findings offer a valuable reference for understanding baseline host-microbiome communication and highlight molecular candidates-such as TNF-&#x3b1;-related genes and mitochondrial pathways-for future experimental validation.

Humans

Virome metatranscriptomic profiling of birch pollen reveals a diverse viral community.

INTRODUCTION: Viruses are increasingly recognized as integral components of plant-associated biological systems. However, their occurrence and diversity in the reproductive tissues of woody plants remain poorly understood. Birch (Betula spp.) produces large quantities of wind-dispersed pollen that can travel over long distances and may harbour viruses or virus-derived nucleic acids originating from the host plant and/or its associated microbiota. METHODS: We investigated the virome of birch pollen collected from trees growing in central and suburban Berlin, Germany. Metatranscriptomic analyses were performed on pooled pollen samples collected in 2020. These analyses were complemented by RT-PCR screening of individually processed pollen samples collected in 2025 from resampled trees. Primer walking was additionally used to recover an extended genome sequence of a pollen-associated birch toti-like virus. RESULTS: Multiple virus-associated contigs were identified in both pooled metatranscriptomic datasets. These included sequences corresponding to the cherry leaf roll virus (CLRV), the birch idaeovirus (BIV) and the birch toti-like virus (BTLV), as well as additional virus-like contigs provisionally assigned to lineages related to the Orthototiviridae, Botourmiaviridae, Endornaviridae, and Chrysoviridae families. RT-PCR analysis of individually processed pollen samples confirmed the continued detection of CLRV, BIV, and BTLV within the Berlin sampling framework. A near-complete genome sequence was recovered from a pollen-derived BTLV isolate from Berlin, showing high amino acid sequence identity to a recently described leaf-derived BTLV isolate from the United States. DISCUSSION: These findings demonstrate that birch pollen harbours a diverse assemblage of plant- and/or microbiome-associated viruses and expand the known tissue distribution and geographic range of BTLV. More broadly, they establish pollen as an underexplored ecological niche for virome research and provide a foundation for future studies on the ecology, transmission dynamics, and epidemiological significance of pollen-associated and pollen-transmitted viruses.

Betula

Benchmarking DNA extraction protocols across use cases for culture-independent Nanopore metagenomics.

Oxford Nanopore Technologies (ONT) sequencing offers several advantages for metagenomics, including long reads, rapid turnaround, low upfront cost, scalability and portability. However, for ONT metagenomics, DNA yield, quality and integrity are important considerations when selecting an extraction method. Many metagenomic extraction methods use harsh lysis conditions to extract a wide range of species and provide an accurate community composition, but these conditions can compromise DNA fragment length. Therefore, extraction methods for ONT metagenomics must balance DNA shearing and recovery with representative community lysis. We systematically evaluated DNA extraction methods for ONT metagenomic sequencing using a use case-oriented framework. Among nearly 50 extraction methods screened, 7 were selected for detailed comparison based on suitability for metagenomics, variation in methodology, availability, cost and processing time: Norgen BioTek Corp's Stool DNA Isolation (NG), Zymo Research's ZymoBIOMICS Quick-DNA HMW MagBead (ZMG), Qiagen's DNeasy Blood and Tissue (QBT), Macherey-Nagel's NucleoMag DNA Microbiome (MN), Zymo Research's ZymoBIOMICS DNA Mini Prep (ZMI), Qiagen's DNeasy PowerSoil/QIAamp PowerFecal Pro (PS) and Qiagen's QIAamp Fast DNA Stool Mini (QIA). Methods were tested using Zymo Research's ZymoBIOMICS Microbial Community Standard (MCS), a matrix-free mock community with known composition. DNA extracts were sequenced on an ONT PromethION using the Rapid Barcoding Kit, except QIA due to insufficient DNA yield. Metrics for the method, DNA extracts, sequencing and genomes were evaluated, revealing trade-offs between methods. The two magnetic bead methods, MN and ZMG, produced the highest mean read length N50 values (13.9 and 16.5&#x2009;kb, respectively) but showed apparent community compositions skewed towards Gram-negative bacteria. In contrast, ZMI and PS maintained a community composition close to expected, with reduced mean read length N50 values (4.5 vs. 7.5&#x2009;kb). Performance across various metrics is presented in the context of the following use cases: maximizing genome coverage and assembly completeness, preserving composition accuracy, targeting specific species and limiting required resources (equipment, time or budget). The metrics and use case considerations presented offer practical guidance for informed selection of DNA extraction methods for ONT metagenomics. For accurate community composition, ZMI or PS are recommended, while PS and ZMG perform best at maximizing genome coverage and assembly completeness. NG and QBT may be the most economical options, though performance trade-offs were observed. Finally, PS may be the preferred method for time-sensitive diagnostic or field applications.

Metagenomics

RNA-seq sheds light on "who is doing what" in the coral Porites lutea.

BACKGROUND: The coral holobiont functions as a complex biogeochemical system, sustained by intricate metabolic exchanges between the host and its associated microbiome. While the taxonomic diversity of these communities is well documented, the specific metabolic roles and biogeochemical contributions of microorganisms across distinct coral compartments, particularly within the endolithic habitats, remain poorly understood. Using RNA-seq, we investigated the active microbiome of healthy stony coral Porites lutea, focusing on the coral tissue, the green endolithic algal layer (Ostreobium layer), and the deeper coral skeleton. RESULTS: We identified distinct, metabolically active communities within these compartments and highlight substantial metabolic redundancy across carbon, nitrogen, and sulfur pathways. Our study provides the first transcriptomic evidence of Ostreobium's ability to transfer fixed carbon to other holobiont members and the coral host. We highlight the critical roles of diverse coral holobiont members in nutrient cycling and maintaining homeostasis through scavenging of reactive oxygen and nitrogen species. CONCLUSIONS: This study provides a novel molecular-level understanding of the functional roles played by diverse coral holobiont members in their respective compartments and underscores that corals harbor distinct microbiomes with wide-ranging functions. Video Abstract.

Animals

Altered ruminal microbiome tryptophan metabolism and their derived 3-indoleacetic acid inhibit ruminal inflammation in subacute ruminal acidosis goats.

BACKGROUND: Subacute ruminal acidosis (SARA) is a digestive disorder that often severely jeopardizes the health and lactation performance of ruminants fed a high-energy diet. Different dairy ruminants exhibit varying degrees of inflammation accompanied by variations in the rumen microbiota when SARA occurs. Our understanding of the occurrence of SARA and varying degrees of rumen epithelial inflammation is lacking. Hence, we performed rumen metagenomic, metagenome-assembled genome and metabolomic analyses, with transcriptome and single-nucleus RNA sequence analyses, to explore the microbial mechanism of SARA occurrence and different degrees of inflammation. RESULTS: A total of 36 goats fed two diets with gradually increasing levels of rumen-degradable starch (RDS) were included in this study, and SARA goats fed 70% concentrate diets supplemented with whole corn (HGW-SARA) and SARA goats fed 70% concentrate diets supplemented with crushed corn (HGC-SARA) were identified. Moreover, 11 goats fed a control basal diet, named LGW-CON, were also included. Compared with those in the LGW-CON group, the rumen fermentation capacity was enhanced, accompanied by ruminal epithelial and systemic inflammation, in goats from HGW-SARA and HGC-SARA. Between them, HGC-SARA goats presented less inflammation. Notably, the ruminal inflammation-related pathways were increased only in the HGW-SARA group but not in the HGC-SARA group. Metagenomic analysis revealed that the &#x3b2; diversity of SARA goats was significantly different from that of LGW-CON goats. Ruminococcus significantly increased in both SARA groups, whereas Prevotella and Bacteroidales significantly decreased, which was accompanied by a decrease in cellulose and hemicellulose enzymes and an increase in lysozymes and lipopolysaccharide synthesis enzymes. Multi-omics analysis of the ruminal contents and tissues suggested that epithelial inflammation was caused by disturbed ruminal microbiome-induced Th17 cell differentiation and IL-17 signalling pathway activation. Comparative analyses between the HGW-SARA and HGC-SARA groups highlighted the importance of Selenomonas and Bifidobacterium, as well as bacterial tryptophan metabolism, in the production of 3-indoleacetic acid, which mitigated ruminal epithelial inflammation by modulating Th17 cells and inhibiting IL-17 signalling. Ruminal microbiota transplantation from HGW-SARA goats to healthy dairy goats and mice revealed the role of microbes in epithelial inflammation. Additionally, 3-indoleacetic acid supplementation reduced rumen inflammation and the IL-17 concentration in the serum, improved VFAs absorption, and enhanced milk production. CONCLUSIONS: This study unveiled that after SARA was induced by high-concentrate feeding, the rumen homeostasis was disrupted, and rumen fiber degradation capacity of dairy goats decreased, but the LPS synthesis capacity increased, and inflammation of the rumen epithelium was observed. However, the ruminal microbial species from the Bifidobacterium and Selenomonas genera and bacterial 3-indole acetic acid are pivotal in mitigating ruminal epithelial inflammation during SARA in dairy goats. This could potentially be attributed to the modulation of ruminal Th17 cell proportions and the inhibition of IL-17 signalling pathways. Video Abstract.

Rumen

Metabolic and endocrine modulation of the gut-adipose tissue axis via pro-, pre-, and postbiotics in overweight dogs: A systematic review.

Canine obesity is a complex metabolic disorder driven by luminal dysbiosis, impaired gut barrier function, and metaflammation. Following PRISMA 2020 guidelines, this systematic review evaluated the efficacy of pro-, pre-, and postbiotics in modulating the gut-adipose tissue axis in overweight dogs (BCS &#x2265; 6/9) or diet-induced obesity models. Searches across PubMed and Dimensions (April 2026) identified seven eligible experimental trials. Results suggest that postbiotic Bifidobacterium animalis subsp. lactis CECT 8145 reduced postprandial glucose AUC by 6 % strictly during energy restriction. Pasteurized Akkermansia muciniphila postbiotics limited diet-induced weight gain, though glucoregulatory impacts were highly strain-specific (AKK2 reduced fasting glucose and insulin resistance indexes, whereas EB-AMDK19 exerted no significant effect). Specific probiotics (including Enterococcus faecium, Bifidobacterium lactis, Lactiplantibacillus plantarum and Bifidobacterium breve) attenuated fasting hyperinsulinemia and preserved circulating adiponectin, but lipid profile improvements (triglycerides and total cholesterol) were inconsistent across trials. In dogs, increased luminal short-chain fatty acids are not consistently mirrored by endocrine responses, so the coupling between microbial metabolites and incretin signaling remains incomplete. A critical lack of standardized reporting for species-validated insulin sensitivity metrics was identified. In conclusion, microbiome-targeted therapies, particularly inanimate postbiotics, may represent useful adjunctive strategies to mitigate metabolic dysregulation in obesogenic environments. However, clinical efficacy remains strictly strain-specific and dependent on host energy balance. Given the scarcity of high-certainty evidence, future trials must integrate dynamic physiological assessments with species-validated surrogate indexes alongside standardized dietary controls.

Animals

Genetic modification of the shikimate pathway to reduce lignin content in switchgrass (Panicum virgatum L.) significantly impacts plant microbiomes.

UNLABELLED: Switchgrass (Panicum virgatum L.) is considered a sustainable biofuel feedstock, given its fast-impact growth, low input requirements, and high biomass yields. Improvements in bioenergy conversion efficiency of switchgrass could be made by reducing its lignin content. Engineered switchgrass that expresses a bacterial 3-dehydroshikimate dehydratase (QsuB) has reduced lignin content and improved biomass saccharification due to the rerouting of the shikimate pathway towards the simple aromatic protocatechuate at the expense of lignin biosynthesis. However, the impacts of this QsuB trait on switchgrass microbiome structure and function remain unclear. To address this, wild-type and QsuB-engineered switchgrass were grown in switchgrass field soils, and samples were collected from inflorescences, leaves, roots, rhizospheres, and bulk soils for microbiome analysis. We investigated how QsuB expression influenced switchgrass-associated fungal and bacterial communities using high-throughput Illumina MiSeq amplicon sequencing of ITS and 16S rDNA. Compared to wild-type, QsuB-engineered switchgrass hosted different microbial communities in roots, rhizosphere, and leaves. Specifically, QsuB-engineered plants had a lower relative abundance of arbuscular mycorrhizal fungi (AMF). Additionally, QsuB-engineered plants had fewer Actinobacteriota in root and rhizosphere samples. These findings may indicate that changes in the plant metabolism impact both AMF and Actinobacteriota similarly or potential interactions between AMF and the bacterial community. This study enhances understanding of plant-microbiome interactions by providing baseline microbial data for developing beneficial bioengineering strategies and by assessing nontarget impacts of engineered plant traits on the plant microbiome. IMPORTANCE: Bioenergy crops provide an important strategy for mitigating climate change. Reducing the lignin in bioenergy crops could improve fermentable sugar yields for more efficient conversion into bioenergy and bioproducts. In this study, we assessed how switchgrass engineered for low lignin impacted aboveground and belowground switchgrass microbiome. Our results show unexpected reductions in mycorrhizas and actinobacteria in belowground tissues, raising questions on the resilience and function of genetically engineered plants in agricultural systems.

Panicum

Assessment of multiple probiotic strains that protect Montipora capitata coral from infection by Vibrio coralliilyticus.

Coral disease outbreaks threaten reef ecosystems, often leading to widespread mortality and declines in coral cover. Outbreaks of tissue loss diseases like acute Montipora white syndrome (aMWS) have impacted coral populations that include the Hawaiian rice coral (Montipora capitata). Multiple strains of Vibrio coralliilyticus are known pathogens, and strain OCN008 has been demonstrated as an etiological agent of aMWS in Hawai'i. Recent work has demonstrated that probiotic bacterial strains can be used to directly treat or prevent transmission (prophylaxis) of coral diseases. Based on their production of zones of inhibition and isolation from disease-resistant corals, Pseudoalteromonas ardens R96, Pseudoalteromonas obscura P94, strain Y97 (the genomic similarity to Pseudoalteromonas piscicida is presented), Pseudoalteromonas umbrosa B95, and Vibrio tetraodonis subsp. pristinus OCN044 were assessed for their ability to impair V. coralliilyticus OCN008 infection of M. capitata during laboratory infection trials. Individual inoculation of each of the five aforementioned strains on M. capitata fragments for 48 h prior to V. coralliilyticus OCN008 inoculation resulted in up to a 93.75% reduction in mortality. These results indicate that strains of Pseudoalteromonas and Vibrio can act as prophylactics to prevent M. capitata mortality from V. coralliilyticus OCN008 infection and provide tools to improve disease resilience for Pacific corals.IMPORTANCECoral disease outbreaks are a growing threat to the continued health of coral reefs, which are already vulnerable ecosystems. Strains of the bacterium Vibrio coralliilyticus are known to infect various coral species worldwide, predominantly causing tissue loss and death of the coral animal. Previous research has indicated that constituents from healthy coral microbiomes can act as probiotics to treat or prevent coral infections, and the discovery of effective probiotics is important in the effort to further develop mitigation tools for disease outbreaks. This work provides a demonstration of probiotic species that can protect coral from tissue loss infections by a strain of Vibrio coralliilyticus and is an example of probiotics developed for coral species in Hawai'i. This work provides new tools for probiotic-based coral protection and evidence for this research as a viable avenue to protect coral in their native environments.

Animals

Commensal Dysbiosis Alters Primary Bile Acid Signaling to Drive Mammary Gland Inflammation and Breast Tumor Dissemination.

UNLABELLED: Breast cancer is the most commonly diagnosed malignancy and a leading cause of cancer-related mortality. Hormone receptor-positive (HR+) tumors represent the most prevalent metastatic subtype, and early dissemination remains a major clinical challenge. Commensal dysbiosis, defined as an inflammatory gut microbiome with low biodiversity, promotes metastasis by inducing mammary gland inflammation. In this study, we investigated systemic mechanisms governing dysbiosis-induced metastasis. Metabolomic profiling revealed elevated primary bile acids (BA) in the dysbiotic fecal microbiome. Sequestration and supplementation approaches demonstrated that beyond driving metabolic disease and mammary gland inflammation, primary BAs orchestrated enhanced HR+ tumor dissemination via a prostaglandin E2 (PGE2)-dependent pathway. Analysis of The Cancer Genome Atlas showed that BA, insulin resistance, and PGE2 gene signatures are associated with reduced survival in patients with HR+ tumors. In complementary analyses using the Epic Cosmos electronic health record database, BA sequestrant use was associated with longer restricted mean survival time among patients with metastatic disease. Together, these findings reveal that commensal dysbiosis-associated loss of microbial BA metabolism elevates primary BAs and promotes HR+ metastatic progression through PGE2 signaling. SIGNIFICANCE: Dysbiosis-induced bile acids drive systemic and mammary tissue-specific inflammation that promotes HR+ breast tumor metastasis, supporting the development of strategies targeting microbiome-derived metabolites to reduce metastatic risk in vulnerable populations.

Female

Detection of House Dust Mite-derived DNA in Human Lung Tumors by Whole-Genome Sequencing.

Lung cancer in never-smokers (LCINS) accounts for an increasing proportion of lung cancer cases, yet its risk factors remain poorly understood. House dust mites (HDM) are common aeroallergens that induce airway inflammation, but their potential contribution to lung cancer is unknown. We analyzed unmapped whole-genome sequencing reads from 783 lung cancers from the Sherlock-Lung (n = 621 never-smokers) and EAGLE (n = 162 smokers) cohorts, including 328 matched adjacent normal lung tissues. After removal of human sequences, reads were aligned to reference genomes from the two major HDM species and confirmed by BLAST. Samples with top BLAST matches were classified as HDM-detected. Associations between HDM detection and genomic, microbiome, and bulk RNA-seq-derived immune features were evaluated. HDM-derived DNA was detected at low abundance in a subset of tumors and adjacent normal tissues, with higher detection frequencies in tumors than matched normal tissues and in smokers than never-smokers. In LCINS tumors, HDM detection was not associated with tumor mutational burden or recurrent driver alterations but was associated with modest differences in immune cell composition and a limited but reproducible bacterial co-detection pattern. These findings provide a foundation for investigating aeroallergen-derived DNA signatures and their potential relationship to the lung tumor microenvironment.

Environmental exposure

Microbiome therapeutic PMC101 inhibits the translocation of carbapenem-resistant Klebsiella while enhancing eubiosis in antibiotic-induced dysbiosis mice.

Carbapenem-resistant Enterobacteriaceae (CRE), known for their extensive antibiotic resistance, pose a severe global medical threat. Therefore, developing novel therapeutics beyond conventional antibiotics is urgently needed, and the importance of microbiome therapeutics is increasingly being recognized. This study explores the expanded systemic efficacy of PMC101, a microbiome therapeutic, beyond intestinal CRE infections and investigates its mechanism of action from a microbiome perspective. First, the genetic characteristics of the novel strain were identified through whole-genome analysis, and a scalable cultivation process was established as part of the overall development of this microbiome therapeutic. PMC101 increased the survival rate to 100%, significantly reduced disease severity scores, and prevented weight loss in CRE-infected mice treated with antibiotics. These effects are attributed to the inhibition of CRE growth in stool and the reduced detection of CRE in the lungs and kidneys, indicating suppression of systemic translocation. Metagenomic analysis revealed that PMC101 prevented the reduction in microbial population caused by antibiotics and CRE infection, restored species diversity indices, and mitigated dysbiosis while promoting eubiosis. This CRE translocation suppression was closely associated with increased CRE translocation-microbiome index, defined as the ratio of Bacteroidetes to Proteobacteria. This relationship was further confirmed through simulations using a human intestinal microbial ecosystem model. Additionally, increases in short-chain fatty acids, reductions in excessive inflammatory responses, and decreases in tissue damage were observed, all of which contribute to preventing CRE translocation. Finally, pathogen inhibition effects and safety tests were conducted, confirming the prophylactic potential of PMC101 as a microbiome therapeutic. These findings strongly support PMC101 as a promising candidate for future microbiome-based therapies against CRE infections.

Animals

Hyperprogression Upon Cemiplimab Alone or With Short Course Chemotherapy in PD-L1 &#x2265; 50% Non-small Cell Lung Cancer: A Biomarker Guided Multicenter International Phase 2 Trial-HYPERBOLIC Study.

BACKGROUND: Immune checkpoint inhibitor (ICI) monotherapy is the standard first-line treatment for advanced non-small cell lung cancer (NSCLC) with PD-L1 &#x2265; 50%; however, up to 30% of patients experience early progression or death, including cases of hyperprogressive disease (HPD). High baseline levels (&#x2265; 30.5%) of circulating CD10- low-density neutrophils (LDNs) have been associated with increased HPD occurrence. Emerging evidence suggests that combining ICI with platinum-based chemotherapy (PCT) may mitigate the risk of HPD. Currently, no prospective studies have addressed HPD prevention in this context. PATIENTS AND METHODS: HYPERBOLIC (NCT07274384) is a phase 2, randomized, open-label, multicenter, international trial evaluating whether adding 3 cycles of PCT to first-line cemiplimab reduces HPD rate in stage IV NSCLC with PD-L1 &#x2265; 50% and CD10- LDNs (identified by flow cytometry as CD15&#x207a;CD11b&#x207a; within the PBMC fraction, with immature cells defined by loss of CD10) &#x2265; 30.5%. Seventy-four patients will be randomized (1:1 ratio) to receive cemiplimab alone or cemiplimab plus 3 PCT cycles, followed by cemiplimab maintenance. Randomization will be stratified by Lung Immune Prognostic Index. The first computed tomography scan at week 7 after treatment start will assess HPD occurrence, defined as RECIST v 1.1. disease progression with a delta tumor growth rate (&#x394;TGR) &#x2265; 50% and/or TGR ratio &#x2265; 2. The primary endpoint will be the combined rate of HPD and early death (death within 12 weeks with no radiological evaluation). Secondary endpoints will be HPD rate according to alternative definitions, overall survival, progression free survival, objective response rate, and safety. An extensive translational research platform will include spatial transcriptomics of tumor tissue, single-cell RNA sequencing of PBMCs, circulating-free DNA and plasma factors profiling, and saliva/stool microbiome genomics and metabolomics, to longitudinally explore tumor-host dynamic interactions during treatment. CONCLUSION: to our knowledge, HYPERBOLIC is the first prospective, biomarker-driven trial investigating early treatment escalation based on HPD risk in PD-L1-high NSCLC.

CD10