A simple statistical test of taxonomic or functional homogeneity using replicated microbiome sequencing samples

Area of Science:

• Microbiology
• Bioinformatics
• Statistical analysis

Background:

• Microbiome analysis requires methods to assess sample homogeneity.
• Understanding taxonomic and functional distribution across samples is key.
• Current methods may not adequately address compositional variability.

Purpose of the Study:

• To introduce a novel non-parametric statistical test for assessing microbiome homogeneity.
• To evaluate the homogeneity of microbial composition within a human stool sample.
• To provide a computational tool for microbiome variability analysis.

Main Methods:

• Developed a "triangulation test" based on three-way sample comparisons.
• Required multiple biological replicates for each sample.
• Applied the test to human stool samples analyzed using MEGAN software.

Main Results:

• The triangulation test rejected the null hypothesis of homogeneity.
• Significant differences in taxonomic and functional distributions were found between stool locations.
• Microbial composition varied significantly on a macroscopic scale.

Conclusions:

• Human stool microbial composition is heterogeneous macroscopically.
• Pooling samples from different locations is a valid practice for microbiome studies.
• The triangulation test is a valuable tool for microbiome homogeneity assessment.