Table 1.

Sensitivity analysis for the causal association between blood metabolites and GC

		WM		MR-Egger		Heterogeneity		Pleiotropy		Steiger test
Metabolites	N	OR (95CI%)	p-value	OR (95CI%)	p-value	Q(I2)	p-value	Intercept	p-value	Causal_direction	p-value	Power
Lipid
linoleate (18:2n6)	17	0.11 (0.01–0.94)	0.0435	0.59 (0.00–430.16)	0.878	3.76(0%)	0.999	−0.026	0.6	TRUE	3.1E-80	1
hexadecanedioate	25	1.17 (0.60–2.28)	0.644	1.14 (0.56–2.32)	0.727	15.58(0%)	0.903	0.022	0.182	TRUE	7E-214	1
taurochenodeoxycholate	13	1.68 (0.88–3.18)	0.115	1.40 (0.62–3.15)	0.433	5.3(0%)	0.947	0.014	0.568	TRUE	7.7E-98	1
Peptide
gamma-glutamylglutamate	10	0.49 (0.21–1.14)	0.0962	0.39 (0.08–1.98)	0.291	3.57(0%)	0.937	0.012	0.793	TRUE	3.4E-69	1
phenylalanylphenylalanine	4	0.20 (0.02–1.55)	0.122	0.23 (0.00–51.42)	0.649	0.96(0%)	0.812	−0.01	0.895	TRUE	9.1E-25	1
Amino acid
3-methyl-2-oxovalerate	33	8.93 (1.20–66.37)	0.0323	9.29 (0.65–133.83)	0.112	34.08(6.09%)	0.368	−0.007	0.69	TRUE	2E-211	1
Xenobiotics
piperine	11	1.66 (0.73–3.76)	0.223	1.26 (0.33–4.84)	0.746	10.59(5.60%)	0.39	0.028	0.448	TRUE	6.4E-59	1

Table 1 displays a sensitivity analysis to validate the association between specific blood metabolites and gastric cancer risk. It details the odds ratios with 95% confidence intervals for each metabolite, calculated using various Mendelian Randomization methods: Weighted Median, MR-Egger, and the Steiger test, which confirms the direction of causality. It also evaluates heterogeneity and pleiotropy, which assess the variability of genetic instruments and whether SNPs influence outcomes via pathways other than the metabolite in question, respectively. The number of SNPs used as instrumental variables for each metabolite is provided. P-values are given for each analysis, indicating the statistical significance of the findings