Microbiome最新文献

{"title":"A single amplified genome catalog reveals the dynamics of mobilome and resistome in the human microbiome.","authors":"Tetsuro Kawano-Sugaya, Koji Arikawa, Tatsuya Saeki, Taruho Endoh, Kazuma Kamata, Ayumi Matsuhashi, Masahito Hosokawa","doi":"10.1186/s40168-024-01903-z","DOIUrl":"10.1186/s40168-024-01903-z","url":null,"abstract":"<p><strong>Background: </strong>The increase in metagenome-assembled genomes (MAGs) has advanced our understanding of the functional characterization and taxonomic assignment within the human microbiome. However, MAGs, as population consensus genomes, often aggregate heterogeneity among species and strains, thereby obfuscating the precise relationships between microbial hosts and mobile genetic elements (MGEs). In contrast, single amplified genomes (SAGs) derived via single-cell genome sequencing can capture individual genomic content, including MGEs.</p><p><strong>Results: </strong>We introduce the first substantial SAG dataset (bbsag20) from the human oral and gut microbiome, comprising 17,202 SAGs above medium-quality without co-assembly. This collection unveils a diversity of bacterial lineages across 312 oral and 647 gut species, demonstrating different taxonomic compositions from MAGs. Moreover, the SAGs showed cellular-level evidence of the translocation of oral bacteria to the gut. We also identified broad-host-range MGEs harboring antibiotic resistance genes (ARGs), which were not detected in the MAGs.</p><p><strong>Conclusions: </strong>The difference in taxonomic composition between SAGs and MAGs indicates that combining both methods would be effective in expanding the genome catalog. By connecting mobilomes and resistomes in individual samples, SAGs could meticulously chart a dynamic network of ARGs on MGEs, pinpointing potential ARG reservoirs and their spreading patterns in the microbial community. Video Abstract.</p>","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"188"},"PeriodicalIF":13.8,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11446047/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142365790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strain-resolved de-novo metagenomic assembly of viral genomes and microbial 16S rRNAs.","authors":"Annika Jochheim, Florian A Jochheim, Alexandra Kolodyazhnaya, Étienne Morice, Martin Steinegger, Johannes Söding","doi":"10.1186/s40168-024-01904-y","DOIUrl":"10.1186/s40168-024-01904-y","url":null,"abstract":"<p><strong>Background: </strong>Metagenomics is a powerful approach to study environmental and human-associated microbial communities and, in particular, the role of viruses in shaping them. Viral genomes are challenging to assemble from metagenomic samples due to their genomic diversity caused by high mutation rates. In the standard de Bruijn graph assemblers, this genomic diversity leads to complex k-mer assembly graphs with a plethora of loops and bulges that are challenging to resolve into strains or haplotypes because variants more than the k-mer size apart cannot be phased. In contrast, overlap assemblers can phase variants as long as they are covered by a single read.</p><p><strong>Results: </strong>Here, we present PenguiN, a software for strain resolved assembly of viral DNA and RNA genomes and bacterial 16S rRNA from shotgun metagenomics. Its exhaustive detection of all read overlaps in linear time combined with a Bayesian model to select strain-resolved extensions allow it to assemble longer viral contigs, less fragmented genomes, and more strains than existing assembly tools, on both real and simulated datasets. We show a 3-40-fold increase in complete viral genomes and a 6-fold increase in bacterial 16S rRNA genes.</p><p><strong>Conclusion: </strong>PenguiN is the first overlap-based assembler for viral genome and 16S rRNA assembly from large and complex metagenomic datasets, which we hope will facilitate studying the key roles of viruses in microbial communities. Video Abstract.</p>","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"187"},"PeriodicalIF":13.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11443906/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142361753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stratification of human gut microbiomes by succinotype is associated with inflammatory bowel disease status.","authors":"Laura Anthamatten, Philipp Rogalla von Bieberstein, Carmen Menzi, Janina N Zünd, Christophe Lacroix, Tomas de Wouters, Gabriel E Leventhal","doi":"10.1186/s40168-024-01897-8","DOIUrl":"10.1186/s40168-024-01897-8","url":null,"abstract":"<p><strong>Background: </strong>The human gut microbiome produces and consumes a variety of compounds that interact with the host and impact health. Succinate is of particular interest as it intersects with both host and microbiome metabolism. However, which gut bacteria are most responsible for the consumption of intestinal succinate is poorly understood.</p><p><strong>Results: </strong>We build upon an enrichment-based whole fecal sample culturing approach and identify two main bacterial taxa that are responsible for succinate consumption in the human intestinal microbiome, Phascolarctobacterium and Dialister. These two taxa have the hallmark of a functional guild and are strongly mutual exclusive across 21,459 fecal samples in 94 cohorts and can thus be used to assign a robust \"succinotype\" to an individual. We show that they differ with respect to their rate of succinate consumption in vitro and that this is associated with higher concentrations of fecal succinate. Finally, individuals suffering from inflammatory bowel disease (IBD) are more likely to have the Dialister succinotype compared to healthy subjects.</p><p><strong>Conclusions: </strong>We identified that only two bacterial genera are the key succinate consumers in human gut microbiome, despite the fact that many more intestinal bacteria encode for the succinate pathway. This highlights the importance of phenotypic assays in functionally profiling intestinal microbiota. A stratification based on \"succinotype\" is to our knowledge the first function-based classification of human intestinal microbiota. The association of succinotype with IBD thus builds a bridge between microbiome function and IBD pathophysiology related to succinate homeostasis. Video Abstract.</p>","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"186"},"PeriodicalIF":13.8,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11441152/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Akkermansia muciniphila improve cognitive dysfunction by regulating BDNF and serotonin pathway in gut-liver-brain axis.","authors":"Eun Ji Kang, Min-Gi Cha, Goo-Hyun Kwon, Sang Hak Han, Sang Jun Yoon, Sang Kyu Lee, Moo Eob Ahn, Sung-Min Won, Eun Hee Ahn, Ki Tae Suk","doi":"10.1186/s40168-024-01924-8","DOIUrl":"10.1186/s40168-024-01924-8","url":null,"abstract":"<p><strong>Backrground: </strong>Akkermansia muciniphila, a next-generation probiotic, is known as a cornerstone regulating the gut-organ axis in various diseases, but the underlying mechanism remains poorly understood. Here, we revealed the neuronal and antifibrotic effects of A. muciniphila on the gut-liver-brain axis in liver injury.</p><p><strong>Results: </strong>To investigate neurologic dysfunction and characteristic gut microbiotas, we performed a cirrhosis cohort (154 patients with or without hepatic encephalopathy) and a community cognition cohort (80 participants in one region for three years) and validated the existence of cognitive impairment in a 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced hepatic injury mouse model. The effects of the candidate strain on cognition were evaluated in animal models of liver injury. The expression of brain-derived neurotrophic factor (BDNF) and serotonin receptors was accessed in patients with fibrosis (100 patients) according to the fibrosis grade and hepatic venous pressure gradient. The proportion of A. muciniphila decreased in populations with hepatic encephalopathy and cognitive dysfunction. Tissue staining techniques confirmed gut-liver-brain damage in liver injury, with drastic expression of BDNF and serotonin in the gut and brain. The administration of A. muciniphila significantly reduced tissue damage and improved cognitive dysfunction and the expression of BDNF and serotonin. Isolated vagus nerve staining showed a recovery of serotonin expression without affecting the dopamine pathway. Conversely, in liver tissue, the inhibition of injury through the suppression of serotonin receptor (5-hydroxytryptamine 2A and 2B) expression was confirmed. The severity of liver injury was correlated with the abundance of serotonin, BDNF, and A. muciniphila.</p><p><strong>Conclusions: </strong>A. muciniphila, a next-generation probiotic, is a therapeutic candidate for alleviating the symptoms of liver fibrosis and cognitive impairment.</p>","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"181"},"PeriodicalIF":13.8,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11438137/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phosphorus availability influences disease-suppressive soil microbiome through plant-microbe interactions.","authors":"Yifan Cao, Zongzhuan Shen, Na Zhang, Xuhui Deng, Linda S Thomashow, Ian Lidbury, Hongjun Liu, Rong Li, Qirong Shen, George A Kowalchuk","doi":"10.1186/s40168-024-01906-w","DOIUrl":"https://doi.org/10.1186/s40168-024-01906-w","url":null,"abstract":"<p><strong>Background: </strong>Soil nutrient status and soil-borne diseases are pivotal factors impacting modern intensive agricultural production. The interplay among plants, soil microbiome, and nutrient regimes in agroecosystems is essential for developing effective disease management. However, the influence of nutrient availability on soil-borne disease suppression and associated plant-microbe interactions remains to be fully explored. T his study aims to elucidate the mechanistic understanding of nutrient impacts on disease suppression, using phosphorous as a target nutrient.</p><p><strong>Results: </strong>A 6-year field trial involving monocropping of tomatoes with varied fertilizer manipulations demonstrated that phosphorus availability is a key factor driving the control of bacterial wilt disease caused by Ralstonia solanacearum. Subsequent greenhouse experiments were then conducted to delve into the underlying mechanisms of this phenomenon by varying phosphorus availability for tomatoes challenged with the pathogen. Results showed that the alleviation of phosphorus stress promoted the disease-suppressive capacity of the rhizosphere microbiome, but not that of the bulk soil microbiome. This appears to be an extension of the plant trade-off between investment in disease defense mechanisms versus phosphorus acquisition. Adequate phosphorus levels were associated with elevated secretion of root metabolites such as L-tryptophan, methoxyindoleacetic acid, O-phosphorylethanolamine, or mangiferin, increasing the relative density of microbial biocontrol populations such as Chryseobacterium in the rhizosphere. On the other hand, phosphorus deficiency triggered an alternate defense strategy, via root metabolites like blumenol A or quercetin to form symbiosis with arbuscular mycorrhizal fungi, which facilitated phosphorus acquisition as well.</p><p><strong>Conclusion: </strong>Overall, our study shows how phosphorus availability can influence the disease suppression capability of the soil microbiome through plant-microbial interactions. These findings highlight the importance of optimizing nutrient regimes to enhance disease suppression, facilitating targeted crop management and boosting agricultural productivity. Video Abstract.</p>","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"185"},"PeriodicalIF":13.8,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11439275/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover crop root exudates impact soil microbiome functional trajectories in agricultural soils.","authors":"Valerie A Seitz, Bridget B McGivern, Mikayla A Borton, Jacqueline M Chaparro, Meagan E Schipanski, Jessica E Prenni, Kelly C Wrighton","doi":"10.1186/s40168-024-01886-x","DOIUrl":"10.1186/s40168-024-01886-x","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Cover cropping is an agricultural practice that uses secondary crops to support the growth of primary crops through various mechanisms including erosion control, weed suppression, nutrient management, and enhanced biodiversity. Cover crops may elicit some of these ecosystem services through chemical interactions with the soil microbiome via root exudation, or the release of plant metabolites from roots. Phytohormones are one metabolite type exuded by plants that activate the rhizosphere microbiome, yet managing this chemical interaction remains an untapped mechanism for optimizing plant-soil-microbiome interactions. Currently, there is limited understanding on the diversity of cover crop phytohormone root exudation patterns and our aim was to understand how phytochemical signals selectively enrich specific microbial taxa and functionalities in agricultural soils.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Here, we link variability in cover crop root exudate composition to changes in soil microbiome functionality. Exudate chemical profiles from 4 cover crop species (Sorghum bicolor, Vicia villosa, Brassica napus, and Secale cereal) were used as the chemical inputs to decipher microbial responses. These distinct exudate profiles, along with a no exudate control, were amended to agricultural soil microcosms with microbial responses tracked over time using metabolomes and genome-resolved metatranscriptomes. Our findings illustrated microbial metabolic patterns were unique in response to cover crop exudate inputs over time, particularly by sorghum and cereal rye amended microcosms. In these microcosms, we identify novel microbial members (at the genera and family level) who produced IAA and GA&lt;sub&gt;4&lt;/sub&gt; over time. Additionally, we identified cover crop exudates exclusively enriched for bacterial nitrite oxidizers, while control microcosms were discriminated for nitrogen transport, mineralization, and assimilation, highlighting distinct changes in microbial nitrogen cycling in response to chemical inputs.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;We highlight that root exudate amendments alter microbial community function (i.e., N cycling) and microbial phytohormone metabolisms, particularly in response to root exudates isolated from cereal rye and sorghum plants. Additionally, we constructed a soil microbial genomic catalog of microorganisms responding to commonly used cover crops, a public resource for agriculturally relevant microbes. Many of our exudate-stimulated microorganisms are representatives from poorly characterized or novel taxa, revealing the yet to be discovered metabolic reservoir harbored in agricultural soils. Our findings emphasize the tractability of high-resolution multi-omics approaches to investigate processes relevant for agricultural soils, opening the possibility of targeting specific soil biogeochemical outcomes through biological precision agricultural practices that use cover crops and the microbiome as lev","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"183"},"PeriodicalIF":13.8,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11439266/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Networks as tools for defining emergent properties of microbiomes and their stability.","authors":"Kacie T Kajihara, Nicole A Hynson","doi":"10.1186/s40168-024-01868-z","DOIUrl":"https://doi.org/10.1186/s40168-024-01868-z","url":null,"abstract":"<p><p>The potential promise of the microbiome to ameliorate a wide range of societal and ecological challenges, from disease prevention and treatment to the restoration of entire ecosystems, hinges not only on microbiome engineering but also on the stability of beneficial microbiomes. Yet the properties of microbiome stability remain elusive and challenging to discern due to the complexity of interactions and often intractable diversity within these communities of bacteria, archaea, fungi, and other microeukaryotes. Networks are powerful tools for the study of complex microbiomes, with the potential to elucidate structural patterns of stable communities and generate testable hypotheses for experimental validation. However, the implementation of these analyses introduces a cascade of dichotomies and decision trees due to the lack of consensus on best practices. Here, we provide a road map for network-based microbiome studies with an emphasis on discerning properties of stability. We identify important considerations for data preparation, network construction, and interpretation of network properties. We also highlight remaining limitations and outstanding needs for this field. This review also serves to clarify the varying schools of thought on the application of network theory for microbiome studies and to identify practices that enhance the reproducibility and validity of future work. Video Abstract.</p>","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"184"},"PeriodicalIF":13.8,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11439251/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maternal HIV infection and the milk microbiome.","authors":"Nicole H Tobin, Fan Li, Sean Brummel, Patricia M Flynn, Sufia Dababhai, Dhayendre Moodley, Lameck Chinula, Avy Violari, Mary Glenn Fowler, Vanessa Rouzier, Louise Kuhn, Grace M Aldrovandi","doi":"10.1186/s40168-024-01843-8","DOIUrl":"https://doi.org/10.1186/s40168-024-01843-8","url":null,"abstract":"<p><strong>Background: </strong>Children born to women with HIV but who do not become HIV infected experience increased morbidity and mortality compared with children born to women without HIV. The basis of this increased vulnerability is unknown. The microbiome, specifically the infant gut microbiome, likely plays an important role in infant immune development. The human milk microbiome is thought to have an important role in the development of the infant gut and therefore, if perturbed, may contribute to this increased vulnerability. We investigated the effects of HIV and its therapies on the milk microbiome and possible changes in the milk microbiome before or after infant HIV infection.</p><p><strong>Results: </strong>Seven-hundred fifty-six human milk samples were selected from three separate studies conducted over a 15-year period to investigate the role of HIV and its therapies on the human milk microbiome. Our data reveal that the milk microbiome is modulated by parity (R² = 0.006, p = 0.041), region/country (R² = 0.014, p = 0.007), and duration of lactation (R² = 0.027-0.038, all p < 0.001). There is no evidence, however, using 16S rRNA V4 amplicon sequencing, that the human milk microbiome is altered by HIV infection (R² = 0.003, p = 0.896), by combination antiretroviral therapy (R² = 0.0009, p = 0.909), by advanced maternal disease (R² = 0.003, p = 0.263), or in cases of infant infection either through isolated early mucosal (R² = 0.003, p = 0.197) or early mucosal and breast milk transmission (R² = 0.002, p = 0.587).</p><p><strong>Conclusions: </strong>The milk microbiome varies by stage of lactation, by parity, and by region; however, we found no evidence that the human milk microbiome is altered by maternal HIV infection, disease severity, or antiretroviral therapy. Additionally, we found no association between the milk microbiome and transmission of HIV to the infant. Investigations including higher resolution microbiome approaches or into other potential mechanisms to understand why the approximately one million children born annually to women with HIV escape infection, but do not escape harm, are urgently needed. Video Abstract.</p>","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"182"},"PeriodicalIF":13.8,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11439335/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut microbiota drives colon cancer risk associated with diet: a comparative analysis of meat-based and pesco-vegetarian diets.","authors":"Carlotta De Filippo, Sofia Chioccioli, Niccolò Meriggi, Antonio Dario Troise, Francesco Vitali, Mariela Mejia Monroy, Serdar Özsezen, Katia Tortora, Aurélie Balvay, Claire Maudet, Nathalie Naud, Edwin Fouché, Charline Buisson, Jacques Dupuy, Valérie Bézirard, Sylvie Chevolleau, Valérie Tondereau, Vassilia Theodorou, Claire Maslo, Perrine Aubry, Camille Etienne, Lisa Giovannelli, Vincenzo Longo, Andrea Scaloni, Duccio Cavalieri, Jildau Bouwman, Fabrice Pierre, Philippe Gérard, Françoise Guéraud, Giovanna Caderni","doi":"10.1186/s40168-024-01900-2","DOIUrl":"https://doi.org/10.1186/s40168-024-01900-2","url":null,"abstract":"<p><strong>Background: </strong>Colorectal cancer (CRC) risk is strongly affected by dietary habits with red and processed meat increasing risk, and foods rich in dietary fibres considered protective. Dietary habits also shape gut microbiota, but the role of the combination between diet, the gut microbiota, and the metabolite profile on CRC risk is still missing an unequivocal characterisation.</p><p><strong>Methods: </strong>To investigate how gut microbiota affects diet-associated CRC risk, we fed Apc-mutated PIRC rats and azoxymethane (AOM)-induced rats the following diets: a high-risk red/processed meat-based diet (MBD), a normalised risk diet (MBD with α-tocopherol, MBDT), a low-risk pesco-vegetarian diet (PVD), and control diet. We then conducted faecal microbiota transplantation (FMT) from PIRC rats to germ-free rats treated with AOM and fed a standard diet for 3 months. We analysed multiple tumour markers and assessed the variations in the faecal microbiota using 16S rRNA gene sequencing together with targeted- and untargeted-metabolomics analyses.</p><p><strong>Results: </strong>In both animal models, the PVD group exhibited significantly lower colon tumorigenesis than the MBD ones, consistent with various CRC biomarkers. Faecal microbiota and its metabolites also revealed significant diet-dependent profiles. Intriguingly, when faeces from PIRC rats fed these diets were transplanted into germ-free rats, those transplanted with MBD faeces developed a higher number of preneoplastic lesions together with distinctive diet-related bacterial and metabolic profiles. PVD determines a selection of nine taxonomic markers mainly belonging to Lachnospiraceae and Prevotellaceae families exclusively associated with at least two different animal models, and within these, four taxonomic markers were shared across all the three animal models. An inverse correlation between nonconjugated bile acids and bacterial genera mainly belonging to the Lachnospiraceae and Prevotellaceae families (representative of the PVD group) was present, suggesting a potential mechanism of action for the protective effect of these genera against CRC.</p><p><strong>Conclusions: </strong>These results highlight the protective effects of PVD while reaffirming the carcinogenic properties of MBD diets. In germ-free rats, FMT induced changes reminiscent of dietary effects, including heightened preneoplastic lesions in MBD rats and the transmission of specific diet-related bacterial and metabolic profiles. Importantly, to the best of our knowledge, this is the first study showing that diet-associated cancer risk can be transferred with faeces, establishing gut microbiota as a determinant of diet-associated CRC risk. Therefore, this study marks the pioneering demonstration of faecal transfer as a means of conveying diet-related cancer risk, firmly establishing the gut microbiota as a pivotal factor in diet-associated CRC susceptibility. Video Abstract.</p>","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"180"},"PeriodicalIF":13.8,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11438057/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dietary fibers boost gut microbiota-produced B vitamin pool and alter host immune landscape.","authors":"Erica T Grant, Amy Parrish, Marie Boudaud, Oliver Hunewald, Akiyoshi Hirayama, Markus Ollert, Shinji Fukuda, Mahesh S Desai","doi":"10.1186/s40168-024-01898-7","DOIUrl":"10.1186/s40168-024-01898-7","url":null,"abstract":"<p><strong>Background: </strong>Dietary fibers can alter microbial metabolic output in support of healthy immune function; however, the impact of distinct fiber sources and immunomodulatory effects beyond short-chain fatty acid production are underexplored. In an effort to discern the effects of diverse fibers on host immunity, we employed five distinct rodent diets with varying fiber content and source in specific-pathogen-free, gnotobiotic (containing a 14-member synthetic human gut microbiota), and germ-free mice.</p><p><strong>Results: </strong>Broad-scale metabolomics analysis of cecal contents revealed that fiber deprivation consistently reduced the concentrations of microbiota-produced B vitamins. This phenomenon was not always explained by reduced biosynthesis, rather, metatranscriptomic analyses pointed toward increased microbial usage of certain B vitamins under fiber-free conditions, ultimately resulting in a net reduction of host-available B vitamins. Broad immunophenotyping indicated that the local gut effector immune populations and activated T cells accumulate in a microbiota-dependent manner. Supplementation with the prebiotic inulin recovered the availability of microbially produced B vitamins and restored immune homeostasis.</p><p><strong>Conclusions: </strong>Our findings highlight the potential to use defined fiber polysaccharides to boost microbiota-derived B vitamin availability in an animal model and to regulate local innate and adaptive immune populations of the host. Video abstract.</p>","PeriodicalId":18447,"journal":{"name":"Microbiome","volume":"12 1","pages":"179"},"PeriodicalIF":13.8,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11418204/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}