Peer Bork

In-cell discovery and characterization of a non-canonical bacterial protein translocation-folding complex

Cryo-electron tomography has emerged as a powerful technology for in-cell structural biology and, in combination with breakthroughs in protein structure prediction, offers a unique opportunity for illuminating functions of previously uncharacterized macromolecular complexes. Here, we used the genome-reduced bacterium Mycoplasma pneumoniae as a minimal cell model and determined in-cell maps of an unknown complex located at the cell surface. By combining proteomics, structure prediction, integrative modeling, and bioinformatics, we identified the complex to include the conserved Sec-translocon and an extracellular dome-like structure largely formed by three uncharacterized proteins (Mdps). The Mdps show structural homology to the periplasmic ATP-independent foldase PrsA, with Mdp444 retaining key catalytic residues and activity. Our study provides the first sub-nanometer-resolution maps of the complete bacterial Sec-translocation machinery, depicting its association in SecA-mediated co-translational translocation and its coordination with an extracellular protein-folding system.

Multidisciplinary Delphi consensus statement on minimal standards for clinical metadata and end points in microbiome studies

The lack of harmonization for microbiome-based clinical studies represents a critical issue for microbiome researchers and stakeholders, although microbiome research and clinical studies on the gut microbiome have been intensively conducted for more than a decade. The selection of a minimum metadata set to be analysed and reported during clinical studies with microbiome outcomes, the identification of reference materials, the definition of standardized sampling procedures and data analysis protocols, and the choice of unified clinical end points are still lacking. The two-round Delphi survey, conducted within the framework of the Horizon Europe Human Microbiome Action (HMA) consortium, aimed to standardize metadata collection, sampling procedures, data generation and sharing, and standard operating procedures for aspects of gut microbiome-based clinical studies beyond outcomes. The process involved 72 scientists and experts worldwide in the first round and 61 experts in the second round, with an 85% participation rate from the first to the second round. On the basis of the outcome of the Delphi survey, the HMA consortium provided 15 recommendations that might be taken up by the community at large to promote coherence and harmonization in the way microbiome clinical research is and will be performed. The recommendations mainly focus on the gut microbiome and diseases associated with the gastrointestinal tract and gut-organ axes.

Diet and microbiome shape small-molecule cytokinin pools in mammals

Variations in the latitudinal diversity gradients of the ocean microbiome

Latitudinal diversity gradients (LDGs), which typically decline from the equator to the poles, are a pervasive macroecological pattern. However, their generality and drivers in the ocean microbiome remain widely unresolved. We integrated global-scale metagenomic data with habitat modeling to study marine microbial LDGs across seasons and depths. Surface mixed-layer microbiomes exhibit diversity peaks at (sub)tropical latitudes and a poleward decline, whereas mesopelagic communities (200-1,000 m) show no latitudinal diversity structuring. Taxonomic resolution reveals that the mixed-layer LDG is underpinned by Alphaproteobacteria and Cyanobacteriia, while other taxa exhibit distinct or contrasting LDGs. Diversity structuring also varies by seasons and regions and is governed by temperature and nutrient availability. Together, these findings highlight that, within the ocean microbiome, LDGs are not universal but reflect lineage-specific ecological strategies and responses to environmental gradients. Our study provides fundamental insights into the structuring of ocean microbiome diversity and lays the foundation for predicting responses to environmental change.

Prominent mediatory role of gut microbiome in the effect of lifestyle on host metabolic phenotypes

. These findings highlight distinct and clinically relevant microbiome pathways linking lifestyle behaviors to cardiometabolic risks.One sentence summary:The gut microbiome mediates the impact of diet quality and diversity, physical activity and smoking status - combined in a composite lifestyle score - on cardiometabolic phenotypes.

VIRE: a metagenome-derived, planetary-scale virome resource with environmental context

proGenomes4: providing 2 million accurately and consistently annotated high-quality prokaryotic genomes

The pervasive availability of publicly available microbial genomes has opened many new avenues for microbiology research, yet it also demands robust quality control and consistent annotation pipelines to ensure meaningful biological insights. proGenomes4 (prokaryotic Genomes v4) addresses this challenge by providing a resource of nearly 2 million high-quality microbial genomes, a doubling in scale from previous versions, encompassing over 7 billion genes. Each genome underwent rigorous quality assessment and comprehensive functional annotation by applying multiple standardized annotation workflows, including the systematic identification of mobile genetic elements and biosynthetic gene clusters. proGenomes4 contains 32 887 species with ecological habitat metadata as well as precomputed pan-genomes. This substantially expanded resource provides the microbiology community with a foundation for large-scale comparative studies and is freely accessible via a newly developed command line interface and at https://progenomes.embl.de/.

eggNOG v7: phylogeny-based orthology predictions and functional annotations

The eggNOG (evolutionary genealogy of genes: Non-supervised Orthologous Groups) database is a phylogenomic resource for orthology inference, evolutionary analysis, and functional annotation across eukaryotes, bacteria, and archaea. Previous versions relied on best reciprocal hit triangulation and clustering approaches, which, although effective, faced challenges with the computational demands of large datasets, inconsistent hierarchical orthologous group (OG) reconstruction, and inaccurate classification of multidomain proteins. Here, we present eggNOG v7, the first release implementing a fully phylogenetic, domain-centric workflow. In this pipeline, sequences are first pre-clustered by Pfam domains or de novo clustering, followed by large-scale multiple sequence alignment and phylogenetic tree inference. Speciation and duplication events are then detected using a noise-tolerant algorithm to generate hierarchically consistent, evolutionarily dated OGs. Applied to 59.3 million proteins from 12 535 species, eggNOG v7 produced 3.18 million OGs, reducing singletons, fragmentation, and oversized groups compared to prior versions. Benchmarking against manually curated KEGG functional OGs demonstrated higher functional consistency. Additionally, eggNOG v7 provides updated protein functional annotations and a fully redesigned web interface with protein-centric searches, interactive phylogenies, and functional profiling tools. eggNOG v7 is available at https://eggnogdb.org.

Metalog: curated and harmonised contextual data for global metagenomics samples

Metagenomic sequencing enables the in-depth study of microbes and their functions in humans, animals, and the environment. While sequencing data is deposited in public databases, the associated contextual data is often not complete and needs to be retrieved from primary publications. This lack of access to sample-level metadata like clinical data or in situ observations impedes cross-study comparisons and meta-analyses. We therefore created the Metalog database, a repository of manually curated metadata for metagenomics samples across the globe. It contains 80 423 samples from humans (including 66 527 of the gut microbiome), 10 744 animal samples, 5547 ocean water samples, and 23 455 samples from other environmental habitats such as soil, sediment, or fresh water. Samples have been consistently annotated for a set of habitat-specific core features, such as demographics, disease status, and medication for humans; host species and captivity status for animals; and filter sizes and salinity for marine samples. Additionally, all original metadata is provided in tabular form, simplifying focused studies e.g. into nutrient concentrations. Pre-computed taxonomic profiles facilitate rapid data exploration, while links to the SPIRE database enable genome-based analyses. The database is freely available for browsing and download at https://metalog.embl.de/.

Lactococcus A phages predict ACLF while Enterococcus B phages predict bacterial infection in decompensated cirrhosis

Background & Aims As portal hypertension progresses in cirrhosis, bacterial translocation across a compromised gut barrier leads to endotoxemia, systemic inflammation and immune dysfunction. Gut phages play a key role in these processes by influencing bacteria-host interactions. This study explores the role of the human gut virome in acute decompensation of cirrhosis and acute-on-chronic liver failure (ACLF). Methods The fecal virome was longitudinally assessed by metagenomic sequencing in two independent cohorts: 93 patients (292 samples) with acute decompensation or ACLF from the PREDICT study, and 94 patients (94 samples) with decompensated cirrhosis undergoing TIPS (transjugular intrahepatic portosystemic shunt) surgery collected in a tertiary care setting. Besides descriptive analysis, phages were grouped according to their predicted bacterial host and lifestyle, and associated with clinical parameters. Results Phage alpha-diversity was higher in patients with ACLF and correlated with ACLF severity. In the absence of ACLF, the phageome was dominated by virulent phages, but in ACLF, temperate phages became more prevalent. Genus-level analysis showed that phageomes were highly patient-specific. Lactococcus A phages were the only phage-host group predicting ACLF development (odds ratio [OR] = 14; Fisher test p = 0.0129). Enterococcus B phages (OR = 14.7; p = 0.0015; adj. p = 0.037) and their bacterial hosts (OR = 2.8; p = 0.020) were significantly more prevalent in cases of proven systemic bacterial infection. The presence of both phage families was linked to increased 90-day mortality rates. Conclusion ACLF is characterized by increased fecal virome diversity and a shift from virulent toward temperate phages at disease onset. Our study links Lactococcus A phages to ACLF development, and Enterococcus B phages to bacterial infection, while both are associated with increased 90-day mortality. Clinical trial number NCT03056612. Impact and implications The human gut virome is a poorly investigated part of the human gut microbiome, especially in the context of decompensated cirrhosis and acute-on-chronic liver failure. This study identified two phage groups ( Lactococcus A phages and Enterococcus B phages) with particular prognostic value. In the future, virome analysis of fecal samples could be useful for patient stratification in clinical practice.

SMART v10: three decades of the protein domain annotation resource

A gut microbiome-kidney-heart axis predictive of future cardiovascular diseases.

Metalog: curated and harmonised contextual data for global metagenomics samples

The JEDI marker as a universal measure of planetary biodiversity

Planetary microbiome structure and generalist-driven gene flow across disparate habitats

Alcohol-related liver disease disrupts bile acid synthesis and is associated with compensatory gut microbiota changes

Nuclear rerouting of paracrine Fgf3 in source cells represses target genes to pattern morphogen responses

The postbiotic ReFerm® versus standard nutritional support in advanced alcohol-related liver disease (GALA-POSTBIO): a randomized controlled phase 2 trial

Impaired gut barrier function may lead to progression of liver fibrosis in people with alcohol-related liver disease. The postbiotic ReFerm® can lower gut barrier permeability and may thereby reduce fibrosis formation. Here, we report the results from an open-labelled, single centre randomized controlled trial where 56 patients with advanced, compensated, alcohol-related liver disease were assigned 1:1 to receive either ReFerm® (n = 28) or standard nutritional support (Fresubin®, n = 28) for 24 weeks. The primary outcome was a ≥ 10% reduction of the fibrosis formation marker alpha-smooth muscle actin in liver biopsies, assessed by a blinded pathologist using automated digital imaging analysis. Paired liver biopsies meeting quality criteria for the primary outcome were available for 40 participants (ReFerm®, n = 21 and Fresubin®, n = 19). This reduction was observed in 29% of patients receiving ReFerm®, compared to 14% with Fresubin® (OR = 2.40; 95% CI 0.63 to 9.16; p = 0.200). No treatment-related serious adverse events occurred. Our findings suggest that ReFerm® may reduce liver fibrosis by enhancing gut barrier function, potentially preventing the progression of alcohol-related liver disease. Impaired gut barrier function is a central driver of alcohol-related liver disease. This study indicates that the postbiotic ReFerm® improves gut barrier function and reduce liver stiffness and liver fibrosis, suggesting the gut barrier function as a potential treatment target.

Hidden but discoverable diversity in the global microbiome

Cataloguing Earth’s biodiversity remains one of the most formidable challenges in biology, and the greatest diversity is expected to reside among the smallest organisms: microbes. Yet the ongoing census of microbial life is hampered by disparate sampling of Earth’s habitats, challenges in isolating uncultivated organisms, limited resolution in taxonomic marker gene amplicons, and incomplete recovery of metagenome-assembled genomes (MAGs). Here, we quantified discoverable bacterial and archaeal diversity in a comprehensive, curated cross-habitat dataset of 92,187 metagenomes. Clustering 502M sequences of 130 marker genes, we detected 705k bacterial and 27k archaeal species-level clades, the vast majority of which was hidden among ‘unbinned’ contigs. At deeper taxonomic levels, we estimate that 10 archaeal and 145 bacterial novel phyla and around 80k novel genera are discoverable in current data. We identified soils and aquatic environments as novel lineage recovery hotspots, yet predict that discovery will remain in full swing across habitats as more data accrues. Finally, we show that prokaryotic diversity follows power laws, confirming century-old hypotheses on clade size patterns and suggesting that novel lineages arise within common (and fractal) evolutionary patterns, comparable to those among eukaryotic clades and viruses, along the full depth and breadth of the Tree of Life.

In-cell discovery and characterization of a non-canonical bacterial protein translocation-folding complex

Summary Cryo-electron tomography has emerged as powerful technology for in-cell structural biology, and in combination with breakthroughs in protein structure prediction, offers a unique opportunity for illuminating functions of previously uncharacterized macromolecular complexes. Here, we used the genome-reduced bacterium Mycoplasma pneumoniae as a minimal cell model, and determined in-cell maps of an unknown complex located at the cell surface. By combining proteomics, structure prediction, and bioinformatics, we identified the complex to include the conserved Sec-translocon and an extracellular dome-like structure largely formed by three uncharacterized proteins (Mdps). The Mdps show structural homology to a periplasmic ATP-independent foldase, PrsA, with Mdp444 retaining key catalytic residues. Our study provides the first sub-nanometer resolution maps of the complete bacterial Sec-translocation machinery, depicting several conformational states that allow us to suggest a model for translocation initiation, and revealing its coordination with a novel, extracellular, protein-folding system.