TLR4 and irritable bowel syndrome: MFHAS1, however, plays a role in the modulation of inflammatory responses via macrophage polarization and toll-like receptor signaling (particularly toll-like receptor 2 and toll-like receptor 4).53, 54, 55 The latter drives inflammation on recognition of microbial components (eg, lipopolysaccharide), and multiple studies report increased toll-like receptor expression in the intestinal mucosa of patients with IBS.56