MixOmics: An omics integration "Swiss army knife"

The study of genomics involves examining an organism’s entire genetic makeup, including its DNA sequence, genes, and mechanisms that control gene expression. Proteomics and metabolomics, two other “omics” methods, concentrate on the study of proteins and metabolites, respectively. Researchers can gain new insights into how an organism functions and how it reacts to its surroundings by combining the analysis of these many forms of data. For instance, by fusing genomics data with proteomics and metabolomics data, researchers can acquire a fuller knowledge of an organism’s gene expression, protein synthesis, and metabolic processes, as well as how these processes interact to produce health or malfunction to produce disease. This information can offer insightful information for a variety of purposes, such as medication research, disease diagnostics, and environmental monitoring. Searching for patterns or linkages between various data sets is the process of finding correlations between linked datasets. This can offer insightful information about the underlying biological mechanisms and operations of an organism. For instance, a strong positive correlation between two datasets indicates that they are related and that changes in one dataset may be related to changes in the other. Researchers can gain a better understanding of the mechanisms underlying biological processes and how they are controlled by finding these relationships. This can be helpful for a number of applications, including determining prospective targets for medical intervention or forecasting the effects of new medications. 

I looked through the literature to find any methods that could combine different -omics datasets. There are numerous possibilities, as there are for each assignment in bioinformatics. The “mixOmics” package (available for download and installation from Bioconductor) is one of the best tools currently available for performing this type of integration analysis, in my opinion, when taking into account factors like ease of installation, documentation quality, a strong user community, user support, and published analyses.

The mixOmics strategy

Several multivariate techniques for integrating numerous datasets are included in the mixOmics package. In this problem space, where there are many more attributes than samples, multivariate analysis is ideally suited. The analysis makes it simpler for a human analyst to recognize patterns and understand correlations by lowering the dimension of the data. “Partial least squares” is one of the most popular algorithm categories in mixOmics for this task. A mathematical tool called partial least squares (PLS) is used to examine connections between two or more datasets. Similar to PCA analysis, but with a focus on maximizing correlation/covariance across latent variables, it works by discovering the underlying patterns and correlations in the data and using this knowledge to create a set of “composite” variables that reflect the most crucial elements of the data.

The links between the datasets can then be inferred or predicted using these composite (latent) variables. For instance, the PLS approach can be used to determine the precise features of one dataset that are most highly linked with the other and then create composite variables based on these features if it is known that the two datasets are related in some way. PLS can be used to predict relationships between the dependent and independent variables since it is more resistant to highly correlated features than PCA. By incorporating a “feature-selection” option dubbed “sparse PLS” or simply “sPLS” that employs “lasso” penalization to remove unneeded features from the final model to improve interpretation and also minimize computing time, mixOmics advances the PLS approach. The regularization term, which increases the complexity of the ordinary least squares regression model, is how lasso regression operates. The “lasso” regularization term effectively removes the less significant predictors from the model by forcing their coefficients to be zero.

As a result, the model is made simpler, easier to understand, and more capable of producing precise predictions. For datasets with many factors, lasso regression is especially helpful since it can help to pinpoint the most crucial predictors and lessen the chance of the model becoming overfit.