Figure 1.

LPS in healthy individuals is produced by GM or enters through food. In inflammatory conditions or in a “leaky gut”, it can overcome the epithelial barrier, determining important effects on the immune system: in particular, APC are stimulated to produce TNF-alpha and IL-12. B-lymphocytes increase antibody production, while also producing TNF-alpha and IL-6, while T-lymphocytes are shifted towards a Th1/Th17 expression pattern. Finally, LPS can enter the bloodstream, inducing chronic or acute endotoxemia.