Table 4. Efficacy of blockers: summary of post hoc analyses* from bitter rankings in the paired-comparison test ¹ by TAS2R38 genotype for each of the two blockers when combined with PROP in each of the two groups: children and adults (means ± SEM).

Blocker = NaG	Genotype	PROP	PROP+NaG	NaG	Diluent
Children	AA	2.7±0.2a	2.4±0.2a	2.8±0.2a	2.1±0.2a
	AP	3.5±0.1a	3.1±0.1a	1.9±0.1b	1.6±0.1b
	PP	3.5±0.1a	3.2±0.1a	1.6±0.1b	1.7±0.1b
	All genotypes	3.3±0.1a	2.9±0.1a	2.1±0.1b	1.7±0.1b
Adults	AA	2.5±0.2a,b	3.0±0.1a	2.5±0.2a,b	1.9±0.2b
	AP	3.5±0.1a	3.3±0.1a	1.8±0.1b	1.4±0.1b
	PP	3.5±0.1a	3.4±0.1a	1.9±0.1b	1.2±0.1b
	All genotypes	3.3±0.1a	3.2±0.1a	2.0±0.1b	1.5±0.1c
Blocker = MSG	Genotype	PROP	PROP+MSG	MSG	Diluent
Children	AA	2.4±0.2a	2.8±0.2a	2.8±0.2a	2.0±0.2a
	AP	3.3±0.1a	3.0±0.1a	2.2±0.2b	1.5±0.1c
	PP	3.2±0.2a	3.1±0.2a	1.8±0.2b	1.9±0.2b
	All genotypes	3.0±0.1a	3.0±0.1a	2.3±0.1b	1.7±0.1c
Adults	AA	2.6±0.2a	2.7±0.2a	2.8±0.2a	1.9±0.2a
	AP	3.4±0.1a	3.2±0.1a	2.0±0.1b	1.4±0.1c
	PP	3.5±0.1a	3.3±0.1a	2.0±0.1b	1.2±0.1b
	All genotypes	3.2±0.1a	3.1±0.1a	2.2±0.1b	1.5±0.1c

Abbreviations: PROP, propylthiouracil; SEM, standard error of the mean. Putative bitter blockers—NaG, 0.3 M sodium gluconate; MSG, 0.1 M glutamate. Rankings for bitterness range from 1 (least) to 4 (most); see Table S1 for ranking procedure. Different letters indicate rankings that are statistically different from each other within each row. Genotypes (AA, AP, PP) refer to the bitter-sensitive (P) and bitter-insensitive (A) forms of A49P alleles of the TAS2R38 bitter receptor gene.¹All Friedman statistical tests of rank tests were significant at p≤0.05.