Microbiome最新文献

Background: The canine microbiome is a vastly understudied area relative to the importance of dogs in society, particularly given the potential importance of the microbiome in veterinary medicine. This has led to a large knowledge gap in the basic taxonomy and functions of the canine gut microbiome and an overreliance on human databases for canine-specific research. Using a broad sample set, long read sequencing, short read sequencing, and metagenomic assembly approaches, we have produced the most comprehensive microbiome resource in all companion animal research.

Results: Here, we describe the recovery of 240 core species that account for > 80% of the canine gut microbiome when tested on an independent validation dataset. We uncovered > 900 new canine-specific strains, 89 novel species, and 10 novel genera, providing a dramatic increase in previous knowledge of the canine microbiome and allowing for mapping rates of up to 95%, a 70% increase on historic mapping rates of ~ 25% using publicly available resources. Through detailed annotation of function, we demonstrate the potential importance of the novel species and genera to health and nutrition and provide evidence of new canine-adapted strains of existing genera and species previously unknown to inhabit canines that provide important metabolic function to the canine host. We discovered the canine microbiome has an expansive ability to metabolize carbohydrates, providing insight into how canines process diverse carbohydrates given their known limited host genomic potential. We uncovered a range of species with abilities to produce butyrate, propionate, and vitamins, highlighting the importance of the canine microbiome to host nutrition. We describe two novel Peptacetobacter species that could regulate host bile acid metabolism, an important finding in the context of chronic GI disease in pets. We demonstrated all new species and genera had no known virulence, suggesting they are commensal and, finally, provided a baseline for antimicrobial resistance in the microbiota species of healthy pets.

Conclusions: This work gives entirely new perspectives on the functional capabilities of the canine gut microbiome, suggesting the canine microbiome is distinct, presumably having evolved to its host, diet, and environment over several millennia. Video Abstract.

Background: The nasal microbiome, a dynamic assemblage of commensals and opportunistic pathogens, is crucial to human health.

Results: Using cross-sectional data from 1,608 adults and longitudinal sampling of 149 individuals over 8-22 months, we identified nine nasal community state types (CSTs), defined by bacterial density and indicator taxa, with varying stability and transition patterns. Core taxa such as Staphylococcus epidermidis and Cutibacterium acnes were highly stable, while opportunistic pathogens like Staphylococcus aureus and Moraxella catarrhalis had shorter residence times. Interactions between Dolosigranulum pigrum and Corynebacterium pseudodiphtheriticum/propinquum were linked to reduced S. aureus colonization. Host factors, including age and biological sex, significantly shaped microbiome dynamics: men exhibited higher bacterial densities and pathogen colonization, while women showed more stable commensal-dominated CSTs. Aging was associated with shifts in CST frequencies, with declining S. aureus and increasing Enterobacterales.

Conclusions: These findings reveal potential strategies by modulating nasal microbiome dynamics to reduce pathogen colonization and improve health. Video Abstract.

Background: Chicken coccidiosis caused by Eimeria tenella (E. tenella) poses a major threat to global poultry production, with its tropism for the caecal microenvironment and dynamic interactions with the resident microbiota remaining incompletely understood. The caecal microbiota plays a critical role in host‒parasite interplay, yet the mechanisms through which microbial homeostasis influences E. tenella development and host resistance remain elusive. This study aimed to elucidate the causal relationship between caecal dysbiosis and E. tenella pathogenesis, with a focus on identifying microbiota-derived regulators of parasite development and host immunity.

Results: Antibiotic-induced caecal dysbiosis (ABX) significantly impaired E. tenella macrogametogenesis, demonstrating microbiota-dependent regulation of parasitic development. Faecal microbiota transplantation (FMT) validated this causal link, revealing that microbial reconstitution restored parasite maturation. Notably, Intestinimonas spp. were identified as key inhibitors of E. tenella development through transcriptional regulation of the EtGFAT gene (Eimeria tenella glucosamine: fructose-6-phosphate aminotransferase), a critical mediator of macrogamete formation. Furthermore, the transplantation of Intestinimonas butyriciproducens (I. butyriciproducens) attenuated clinical manifestations of infection while increasing IFN-γ secretion from CD8⁺ T lymphocytes, thereby enhancing host resistance to E. tenella.

Conclusions: This study revealed that caecal microbiota homeostasis is indispensable for E. tenella developmental progression and highlights Intestinimonas as a pivotal microbial regulator of parasite biology. The dual role of I. butyriciproducens in suppressing parasitic virulence and potentiating adaptive immune responses underscores the therapeutic potential of microbiota-targeted strategies. These findings provide a foundation for the development of novel anticoccidial interventions through targeted manipulation of caecal microbial communities. Video Abstract.

Background: The presence of intracellular microbiota in epithelial cells of gastrointestinal tracts (GITs) of dairy cows, as well as their associations with rumen development, remains unclear.

Results: Using a single-cell analysis of host-microbiome interactions (SAHMI) within a single-cell atlas derived from ten GITs tissue types collected from new-born (NB) and adult (AD) cows, we found that 20.5% of the single-cell RNA sequencing reads aligned to reference microbial genomes after filtering low-quality single cells and doublets. Comparative analysis revealed that abomasum tissue exhibited the highest proportion of cells detected microbial signals, with Paneth cells possessing the most genes classified as both marker genes and those related to microbial signals. In the NB rumen, Basal cells demonstrated the greatest overlap between differentially expressed genes in AD vs. NB comparison and the microbial signal-related genes. Notably, these microbiota-associated genes, which are mainly linked to Aliiroseovarius crassostreae, Enterobacter sp. T2, and Enzebya pacifica, are implicated in nucleotide excision repair mechanisms, including DNA replication and the cell cycle. Furthermore, bacterial fluorescence in situ hybridization (FISH) analysis indicated that these three microbial species were partially localized within the cytoplasm and nucleus of rumen epithelial cells in NB cattle.

Conclusions: These findings provide substantial evidence supporting the existence of an intracellular microbiome within the GITs of dairy cattle and highlight their potential relationships with rumen development. This research enhances our understanding of the crosstalk between hosts and microbiome during the maturation of ruminants. Video Abstract.

Background: Antibiotic resistance genes (ARGs) are proliferating in wastewater microbiomes, yet the biotic forces shaping their diversity remain poorly understood. Here, we integrate 14 months of metagenomic and metatranscriptomic data from a wastewater treatment plant to reveal that viruses and microeukaryotes, long-overlooked trophic actors, may play an important role in shaping bacterial and ARG diversity.

Results: We show that viral and microeukaryotic communities exhibit strong seasonal dynamics that cascade through the microbial food web, significantly structuring prokaryotic communities and subsequently ARG profiles. Crucially, we find that viral and microeukaryotic diversity are positively associated with bacterial diversity, which in turn shapes ARG diversity, underscoring the regulatory potential of ecological interactions.

Conclusions: Our findings challenge the abiotic-centric paradigm and establish the central role of multi-trophic interactions in shaping ARG dynamics in wastewater ecosystems. Video Abstract.

Background: In high-producing dairy systems, the average productive lifespan of cows is around 2.5-4 years. Persistent productivity and longevity are key determinants of dairy cow production performance and herd profitability. Although gastrointestinal microbiota influences dairy cow productivity, the mechanisms by which host-microbiome interactions support sustained productivity in long-lived dairy cows remain unclear. Therefore, this study integrated the metagenomics and metabolomics of the rumen and rectum, along with serum and milk metabolomics, to elucidate the potential impact of the rumen and rectum microbiota on the productivity of long-lived dairy cows.

Results: Serum alanine aminotransferase (ALT), alkaline phosphatase (ALP), total cholesterol (TC), and high-density and low-density lipoprotein cholesterol (HDL-C and LDL-C) levels in long-lived dairy cows were positively correlated with milk yield (MY) and elevated in long-lived high-yielding (LH) dairy cows, whereas insulin (INS) and glucagon (GCG) were negatively correlated with MY and higher in long-lived low-yielding (LL) dairy cows. Rumen propionate level was elevated in LH group and positively correlated with MY. The rumen microbiome, in LH cows upregulated pathways involved in amino acid, cofactor, and vitamin metabolism. LH cows' rumen and rectum microbial networks had cohesion and vulnerability levels similar to those of LL cows and exhibited dependence on key nodes. The rumen and rectum MY-associated purine metabolites, guanosine and D-ribose-1-phosphate, mediated 65.56% and 67.55% of the significant positive effects of Acidaminococcaceae bacterium and Parabacteroides sp. on MY, respectively. Furthermore, the specific lipid metabolism-associated rumen microbiota module enhanced serum eicosapentaenoic acid (EPA) levels by modulating rumen α-linolenic acid metabolism, thereby promoting the synthesis of Pe(20:5/0:0) in milk, which positively contributed to MY.

Conclusions: This study revealed the potential contributions of the rumen and rectum microbiota to the productivity of long-lived dairy cows via purine metabolites, as well as the potential role of the rumen microbial network module in influencing productivity through α-linolenic acid metabolism, providing new insights for nutritional management strategies aimed at improving the persistent production capacity of dairy cows. Video Abstract.

Background: Early lactation (EL) in high-yield dairy cows represents a critical lactation phase marked by significant metabolic stress, which often provokes health disorders and production losses. The rumen microbiome is instrumental in regulating host health and metabolism. However, its contribution to metabolic stress experienced by EL cows has been largely unexplored.

Results: Metabolic stress was prominently observed during EL in the form of elevated oxidative stress (OS), inflammation, and lipolysis. This stress gradually decreased with the progression of lactation from day in milk (DIM) 21 to 90. To identify the underlying mechanisms, this study analyzed EL cows (DIM 32) and peak lactation (PL, DIM 72) using an integrative approach including rumen metagenomics, rumen metabolomics, host metabolomics, and their interactions. Metagenomic analysis revealed a higher abundance of methanogenic archaea (Methanobrevibacter and Methanosphaera) in EL cows, driving increased methane production and subsequent energy loss. This energy waste likely worsened the negative energy balance and caused excessive lipolysis in EL cows. In contrast, the rumen microbiota of PL cows was enriched with Prevotella species and anti-inflammatory bacterial genera (Bacteroides, Parabacteroides, and Alistipes), which are associated with the alleviation of host metabolic stress. Functional analysis of the rumen microbiota uncovered increased tryptophan biosynthesis in EL cows, driving kynurenine production. Conversely, PL cows exhibited a greater abundance of enzymes involved in tryptophan metabolism, thus facilitating the production of indole-3-acetic acid (IAA). Metabolomics analysis also identified the tryptophan metabolism pathway as a shared link between the rumen and serum. Specifically, the kynurenine pathway, associated with OS and inflammation, was upregulated in EL cows, while the indole pathway, particularly the production of IAA, was markedly elevated in PL cows, which attenuated OS and inflammation.

Conclusions: The study results indicate that the rumen microbiota is pivotal in mitigating metabolic stress in EL cows by modulating tryptophan metabolism. Specifically, the transition from EL to PL was characterized by an enhanced tryptophan-indole pathway and a suppressed tryptophan-kynurenine pathway. The results offer meaningful insights into the microbial mechanisms underlying metabolic stress and identify potential strategies for improving cow health and productivity during lactation. Video Abstract.

Background: True bugs (Heteroptera) have undergone repeated evolutionary shifts between phytophagous and carnivorous feeding strategies. Although gut microbiomes are recognized for aiding dietary adaptation, their function in mediating these transitions is still unclear, specifically, how microbial communities change during dietary evolution and influence the diversification of feeding traits.

Results: Here, we selected a stink bug lineage of the subfamily Asopinae (Pentatomidae), representative of an independent feeding trait transition from phytophagy to carnivory. Their gut microbiomes were analyzed and compared to those of closely related phytophagous species within the Pentatomidae family, as well as predatory assassin bugs from the Reduviidae family, which represent the ancestral heteropteran feeding trait of predation. It was found that Asopinae lack the gammaproteobacterial symbionts and midgut crypts that are conserved in their phytophagous counterparts. Instead, their gut microbiomes converged on a community dominated by Enterococcus (Firmicutes) and select Proteobacteria (Serratia, Yokenella, Proteus), mirroring the microbiome of assassin bugs. This core community persisted despite prey variation, likely maintained through pentatomid ancestral eggshell-piercing behavior, enabling vertical transmission. Metagenomic analysis linked the Asopinae microbiome to functions potentially associated with predation adaptation, including the digestion of chitinous substrates likely sourced from prey's internal body. Through bacterial isolation, genomics, and functional assays, we demonstrated that Serratia mediates chitin degradation, which along with a potential coordination in diet digestion, may also have been involved in an antifungal effect. Meanwhile, an Enterococcus strain exhibits inhibition to multiple pathogens such that may provide protections to the host, potentially via a class III lanthipeptide.

Conclusions: Our findings reveal a coordinated restructuring of the gut microbiome during dietary shifts. The convergence of Asopinae and Reduviidae microbiomes underscores how microbial communities may have facilitated the ecological adaptation, likely by enabling hosts to exploit new dietary niches and providing defense against bacterial and fungal pathogens. Video Abstract.

Background: Intestinal inflammation, often driven by microbial dysbiosis and infections, remains a significant health challenge with limited effective treatments. Identifying probiotic strains with anti-inflammatory properties and elucidating their mechanisms is essential for developing novel therapeutic strategies. This study investigates the molecular mechanisms by which E. hirae-a lactic acid bacterium (LAB) isolated from Ningxiang piglets with low diarrhea incidence-alleviates E. coli-induced intestinal inflammation.

Results: In the present study, comparative analysis showed that Ningxiang piglets exhibited a significantly lower incidence of diarrhea and reduced E. coli abundance compared to Yorkshire piglets. Notably, E. hirae was more abundant in Ningxiang piglets and correlated with elevated secretory IgA levels. Additionally, in vitro antagonism assays found that E. hirae effectively inhibited E. coli growth. In vivo supplementation of E. hirae in E. coli-infected piglets restored intestinal microbial balance, increased levels of short-chain fatty acids (SCFAs) such as acetate and propionate, and mitigated E. coli colonization. Further analyses suggested that acetate and propionate downregulated the MyD88/NF-κB signaling pathway, thereby reducing pro-inflammatory cytokine expression. Molecular docking and MyD88 ^- / -experiments verified that MyD88 is involved in SCFA-mediated protection against E. coli-induced inflammation. Furthermore, analyses of public human datasets revealed that Crohn's disease patients exhibited a similar reduction in SCFA levels and MyD88-NF-κB pathway activation, suggesting potential clinical relevance.

Conclusion: Token together, our results reveal that Ningxiang pig-derived E. hirae alleviates E. coli-induced gut dysbiosis and inflammation potentially through the acetate/propionate-MyD88-NF-κB axis. This work provides mechanistic insights for further exploration of probiotic and postbiotic approaches against bacterial-induced intestinal inflammation. Video Abstract.