New Microbiome Tool Joins Multi-Omics Data With Sixfold Accuracy Boost

Microbial communities are not made of one kind of data. A single gut sample can yield sequencing reads that reveal which bacteria are present, metabolomic profiles that show which molecules those bacteria are producing and consuming, and transcriptomic readouts that capture which genes the microbes are actively expressing. Each of these layers tells part of the story, but the story only makes sense when the layers are read together. That is the premise behind a new computational method called Joint-RPCA, described in Molecular Systems Biology, which promises to make multi-omics integration for microbiome research faster, more accurate, and more interpretable than the general-purpose tools that have dominated the field.

The challenge that Joint-RPCA tackles is deceptively simple to state and notoriously hard to solve. Microbiome data are compositional, meaning sequencing reflects relative rather than absolute abundances. They are sparse, with many measurements containing zeros or missing values. And they span wildly different scales, because metabolomics, proteomics, and genomics generate numbers in different units and magnitudes. Traditional approaches often sidestep these problems by analyzing each data layer separately, using dimensionality reduction techniques such as principal coordinates analysis on a distance matrix. But doing so treats the data layers as independent and ignores the inherent correlations between modalities sampled from the same ecosystem, such as the production of a specific metabolite by a specific bacterium.

Joint-RPCA, developed by Bianca Cordazzo Vargas, Cameron Martino, Liat Shenhav, and colleagues spanning institutions from New York University to the University of California San Diego, the University of Turku, and Ben-Gurion University, addresses these issues head-on. The method builds on the OptSpace matrix completion framework, assuming that the input data matrices share an underlying low-rank structured component. In practice, this means the dominant biological signal, such as the difference between diseased and healthy individuals, can be captured by a small number of latent factors, even when that signal is embedded in a sea of high-rank biological and technical noise. The authors are careful to clarify that low-dimensional signal refers to the dimensionality of the latent phenotype factor, not the fraction of total variance it explains, a distinction that matters greatly in microbiome settings where disease effects may be subtle relative to interpersonal variation.

Mathematically, the workflow begins by transforming each data modality using a robust centered log-ratio transformation, which handles sparsity and compositionality without requiring imputation or pseudocounts. Then, a joint dimensionality reduction is performed via singular value decomposition optimized on a local manifold. The key architectural choice is that the sample space is estimated jointly across all modalities, while the feature space is estimated individually within each modality. This yields a shared scores matrix for subjects and distinct loadings matrices for features in each omic type. The output includes a joint low-dimensional representation of samples, feature loadings indicating each feature’s contribution to the axes of variation, and a denoised feature-feature covariance matrix that can be interpreted as a multipartite network of cross-modal interactions.

To evaluate the method, the team benchmarked it against widely used microbiome approaches, including PCoA with Bray-Curtis and Aitchison distances and the single-modality RPCA, as well as general-purpose multi-omics tools such as MOFA+, iClusterPlus, intNMF, and multiblock sPLS from mixOmics. Using data-driven simulations anchored in real data from the Integrative Human Microbiome Project, with induced sparsity ranging from 12 percent down to 3 percent observed density, Joint-RPCA consistently recovered inflammatory bowel disease-associated structure more reliably than the alternatives. Classification accuracy improved by up to sixfold in this benchmark setting, and the method showed greater Mahalanobis distances between phenotype centroids and higher PERMANOVA pseudo-F statistics across simulated densities.

Consistency of feature selection proved to be another strength. When the researchers compared the top-ranked metabolomic features identified by Joint-RPCA and MOFA+ along the component most strongly associated with IBD diagnosis, Joint-RPCA showed a 60 to 70 percent median overlap in its selections across train-test splits and sparsity levels, whereas MOFA+ exhibited less than 30 percent overlap. This indicates that Joint-RPCA more stably recovers the shared low-dimensional phenotype-associated signal rather than selecting features that fluctuate with each training set. In purely synthetic simulations with traceable signals, Joint-RPCA reliably ranked the specific features carrying induced signals among its top loadings, while competitors showed variable or inconsistent performance, particularly when signals were weak.

The method also excels at recovering biologically validated cross-modal relationships. In a study of biological soil crusts, thin living layers on arid soil surfaces, roughly 70 percent of the microbe-metabolite relationships following a wetting event had been experimentally validated, providing ground truth for benchmarking. Joint-RPCA correctly assigned positive covariance values between the cyanobacterium Microcoleus vaginatus and all metabolites the isolate was known to release, and these metabolites ranked among the top 40 co-varying molecules out of 85 total. This finding remained robust even when the sequencing data were subsampled from 50 percent dense down to 1 percent dense. Compared with correlation-based approaches and the specialized method MMvec, Joint-RPCA and MMvec both achieved significantly higher true-positive rates, precision, and recall, but Joint-RPCA did so more than 100 times faster.

That speed advantage stems from a fundamental design difference. MMvec estimates conditional probabilities between metabolite abundances and microbial reads on a per-read basis, so its runtime scales linearly with the number of sequencing reads. Joint-RPCA resolves the high-dimensionality challenge by construction and operates on a per-sample basis, so its runtime scales with the number of samples instead. In runtime experiments using the FINRISK study, one of the largest multi-omics microbiome cohorts to date with 7,167 individuals, Joint-RPCA completed analyses in minutes that would take MMvec days. When processing two independent IBD cohorts with multiple omic types, MMvec required pairwise analysis of all omic combinations, and some pairs had to be excluded because runtimes exceeded 24 hours, forcing the researchers to extrapolate. Joint-RPCA processed thousands of samples and features across omic types within seconds to minutes.

Applied to real-world data, the method delivered replicable biological findings. In the iHMP dataset, which includes matched metabolomics, proteomics, viromics, metagenomics, and metatranscriptomics from 135 samples, Joint-RPCA separated IBD from non-IBD subjects across all omic layers with a PERMANOVA pseudo-F of 17.04. It identified cross-modal markers including urobilin metabolites and Klebsiella pneumoniae that aligned with prior iHMP findings, and it succeeded where single-modality RPCA failed, using the context of proteomics, viromics, and metagenomics to reveal disease-associated patterns in metatranscriptomic and metabolomic data that were otherwise invisible. The signal replicated in an independent UCSD cohort of 146 subjects, with a significant correlation of 0.47 between the IBD-associated metagenomic feature rankings of the two cohorts, and it held in a third validation dataset combining IBD patients with 824 controls from the American Gut Project. Across all three datasets, Phocaeicola vulgatus emerged as the top bacterial species associated with IBD, consistent with its experimentally demonstrated production of disease-linked proteases.

The method’s reach extends beyond human disease. Applied to multi-omics data from human cadaver decomposition across three forensic facilities, Joint-RPCA captured the progression of accumulated degree days along its second principal component and identified a universal microbial decomposer network shared across geographically and climatically distinct sites, including fungal taxa such as Yarrowia and Candida and the bacterium Thiopseudomonas alkaliphila, which single-modality analyses missed. In mammalian gut microbiomes spanning 25 species and five omic types, Joint-RPCA amplified weak signals from gas chromatography-mass spectrometry metabolomics, improving classification of host taxonomy and digestive strategy from an AUC-ROC of 0.65 with independently ranked features to 0.88 when features were ranked in the joint context. The authors caution that the method assumes a shared low-dimensional structure across modalities, does not explicitly adjust for confounders, and does not directly model temporal dynamics, and they emphasize that their benchmark results should be read as evidence of performance in the specific scenarios studied rather than a universal ranking of integration tools. Still, with open-source implementations in Python through the gemelli package and in R through the mia Bioconductor package, plus a QIIME2 plugin and Galaxy integration, Joint-RPCA arrives as a practical, scalable tool poised to reshape how microbiome scientists read the interconnected layers of microbial ecosystems.

Subject of Research: A domain-aware multi-omics integration method for systems microbiology that jointly factorizes sparse, compositional microbiome data layers.

Article Title: Joint-RPCA: domain-aware multi-omics integration for systems microbiology

Article References: Cordazzo Vargas, B., Martino, C., Dilmore, A. H., Metcalf, J. L., Burcham, Z. M., Lahti, L., Bektanov, A., Borman, T., Salomaa, V., Niiranen, T., Havulinna, A. S., Gregor, R., Eyal, S., Meijler, M. M., Mizrahi, I., Song, S. J., Bartko, A., Dorrestein, P. C., Morton, J. T., … Shenhav, L. (2026). Joint-RPCA: domain-aware multi-omics integration for systems microbiology. Molecular Systems Biology. https://doi.org/10.1038/s44320-026-00236-3

Image Credits: AI Generated

DOI: 10.1038/s44320-026-00236-3

Keywords: multi-omics integration, microbiome, Joint-RPCA, dimensionality reduction, matrix completion, inflammatory bowel disease, metabolomics, metagenomics, compositional data, microbe-metabolite interactions, systems microbiology, computational biology