Table 2.

The mediation effect of gut microbiota on pancreatic cancer via affecting serum metabolites.

Exposure	Mediation	Outcome	β (EM)	β (MO)	β (EO)	Indirect effect	Direct effect	Direct effect OR (95% CI)
Pauljensenia sp000411416	Octanoylcarnitine (c8)	Pancreatic cancer	−0.175	−0.098	0.263	0.017	0.246	1.0172 (0.9945, 1.0404)
Pauljensenia sp000411417	Glutarylcarnitine (C5-DC)	Pancreatic cancer	−0.155	−0.094	0.263	0.015	0.249	1.0146 (0.9957, 1.0340)

β (EM): coefficient from exposure to mediator; β (MO): coefficient from mediator to outcome; β (EO): coefficient from exposure to outcome (total effect). Indirect effect: product of β (EM) and β (MO). Direct effect: total effect minus indirect effect; OR (95% CI): odds ratio for direct effect with 95% confidence interval. All estimates were derived using inverse variance-weighted Mendelian randomization.