In addition, given the increased intestinal permeability caused by Bacteroides overgrowth, more gram-negative bacterial lipopolysaccharides (LPS) may enter systemic circulation and contribute to the development of inflammation and acne lesions through the action of Toll-like receptor (TLR) 2 and TLR4, whose expression is upregulated in acne (Juhlin and Michaëlsson, 1983; Terhorst et al., 2010; Maronese et al., 2023). The gene discussed is TLR4; the disease is acne.