TNF and major depressive disorder: adherent-invasive Escherichia coli adheres to gut epithelial cells using microtubular polymerization, inducing secretion of an inflammation factor.[50] They also replicate in the J774-A1 macrophage cell line and promote macrophages to secrete TNF.[51] The changes in abundance of Firmicutes and Proteobacteria may have a correlation with UC and depression.