I am looking for main differences between two R Objects constructed for analysis of microbiome data: phyloseq object and TreeSummarizedExperiment object
First, I will provide a little information about both objects and then ask the questions later, in order to avoid repetitions of familiar points in the discussion.
Phyloseq:
- Purpose: Phyloseq is a popular R package designed for construction of a phyloseq object which can used for the analysis and exploration of microbiome sequencing data.
- Functionality:
- It provides tools for importing, manipulating, and visualizing microbiome data.
- Phyloseq handles data in a tabular format, where rows represent samples (e.g., microbial communities from different individuals or environments), and columns represent features (e.g., bacterial taxa or operational taxonomic units).
- Users can perform diversity analyses, community comparisons, and visualization of microbial abundance.
- Data Structure:
- Phyloseq primarily uses a data frame-like structure to store sample metadata, feature abundance data, and taxonomic information.
- Typical Workflow:
- Import raw sequencing data, Construct phylogenetic trees (if required).
- Process and filter the data (e.g., rarefaction, normalization).
- Compute alpha and beta diversity metrics.
- Visualize results (e.g., bar plots, heatmaps).
TreeSummarizedExperiment:
- Purpose: TreeSummarizedExperiment is an extension of the SingleCellExperiment class, specifically tailored for microbiome data with hierarchical structures.
- Functionality:
- It combines rectangular experimental data (similar to SingleCellExperiment) with hierarchical tree structures.
- TreeSummarizedExperiment can store both the experimental results (assays) and the hierarchical relationships (trees) simultaneously.
- It is particularly useful for microbiome data where samples are related through phylogenetic trees.
- Data Structure:
- TreeSummarizedExperiment includes additional slots beyond those in SingleCellExperiment:
rowTree
: Represents the hierarchical structure on the rows (e.g., taxa).rowLinks
: Provides link information between rows of assays and the row tree.colTree
: Represents the hierarchical structure on the columns (e.g., samples).colLinks
: Provides link information between columns of assays and the column tree.referenceSeq
(optional): Stores reference sequence data per feature (row).
- The tree slots (
rowTree
andcolTree
) require the tree to be an object of thephylo
class.
- TreeSummarizedExperiment includes additional slots beyond those in SingleCellExperiment:
- Typical Workflow:
- Import microbiome data.
- Construct phylogenetic trees (if available).
- Create a TreeSummarizedExperiment object by combining data, trees, and links.
- Perform analyses that leverage both the rectangular data and tree structures.
I have mentioned the obvious differences above, because I am looking for advice from people with experience with these packages.
My goal is to perform Longitudinal analysis of microbiome data with regards to different parameters of alpha and beta diversity.
I am looking for differences between the two packages in terms of Statistical tests, methodological considerations, community support and programming difficulty.
I would also like to know what these two packages differ in terms of handling different models like Generalized Linear Mixed Models (GLMMs) or Zero-Inflated Binomial Models to account for overdispersion and handles normalization and p-value adjustment
TreeSummarizedExperiment
mainly introduces a new S4 Claas, whilephyloseq
comes with a large set of functions and wrappers to perform common microbiome analysis, such as computing diversity or ordination. Running more complex models probably requires using more specialized packages (e.g. vegan). $\endgroup$