Correlation between gut bacterial community and host
transcriptional profile
To investigate the direct effect of variation in the gut microbiome BC
composition on host gene expression patterns, regression analyses were
performed using the function lm in R (R version 4.1.1). We
selected common bacterial taxa (bacteria families with more than 5%
contribution to total sequence reads counts within each treatment; (7
taxonomic families) and individual genes with evidence for possible
treatment effects (P value <0.1 (9 genes)) from the
gene-level analysis described above. We included treatment and family ID
as covariates to account for specific treatment and family effects on
the relationship between host gut microbiome BC composition and gene
transcription. Moreover, a sequential Bonferroni P value
correction was applied for multiple testing correction (Rice, 1989). We
visualized the pattern of correlation across all genes and bacterial
taxa using a heatmap generated in the pheatmap function in R.