Table 4. ANCOVA with stepwise variable selection results for relative frequencies of the C. coccoides-E. rectales microbial group and F. prausnitzii spp. based on targeted qPCR assays.

Category	C. coccoides-E. rectales n = 170	R2	P value	FDR
Main effects	Disease phenotype	0.06368	0.001	0.006
	NOD2 genotype	0.08250	0.001	0.006
	Anti-TNFα	0.08216	0.001	0.006
	ASA	0.02904	0.009	0.02
	Immunomodulator	0.02548	0.019	0.03
	Race	0.01050	0.125	0.16
	Steroids	0.00002	0.954	0.95
Interactions	Disease phenotype * Race	0.05563	0.003	0.01
	NOD2 * steroids	0.02605	0.056	0.03
Category	F. prausnitzii n = 157	R2	P value	FDR
Main effects	Disease phenotype	0.0662	0.002	0.008
	Smoking	0.0284	0.018	0.03
	Steroids	0.0270	0.017	0.03
	NOD2	0.0033	0.394	0.48
	Age	0.0020	0.500	0.51
	Gender	0.0025	0.456	0.52
Interactions	Smoking * NOD2	0.0528	0.004	0.01
	Age * Gender	0.0274	0.019	0.03

See Materials and Methods. The variables and first order interactions with significant P values (≤0.05) as well as the variables in the first order interactions are listed above. To address multiple comparison issues, the Benjamini-Hochberg method was applied to adjust P-values to the false discovery rate (FDR). The variables and first order interactions with FDR ≤0.05 are bolded.