Fecal microorganisms from normal-diet (ND) and high-fat diet (HD)-fed mice were transplanted into normal-diet mice to investigate whether they increased AF sensitivity, circulating lipopolysaccharide (LPS) levels, and TLR4/NF-κB/NLRP3 inflammatory vesicle signaling pathway expression. Here, TLR4 is linked to atrial fibrillation.