TNF and ulcer disease: Following ulcer onset, decreased levels of NO, iNOS, PGE2, and MTL, alongside increased levels of TNF-α, IL-6, and MDA, directly induce a reduction in the abundance of bacteria, including Rothia, Streptococcus, Corynebacterium, Globicatella, Romboutsia, and Lactobacillus, with this effect being more pronounced in the oral cavity.