['Dysbiosis, an imbalance in the taxonomic composition of the gut bacteria occurring during the critical stages of development, induces lasting shifts in the immunological and metabolic phenotype if accompanied by an inflammatory response. As altered gut microbiota and successful treatment with probiotics have both been demonstrated in cases of colic, we hypothesized here that infants with colic might have low-grade inflammation.', 'In 28 infants with colic and in 12 healthy controls at the age of one month, we measured the following serum immunological biomarkers: cytokines interleukin 1β (IL-1β); IL-6; IL-10; tumor necrosis factor α (TNF-α); interferon γ (IFN-γ); chemokines IL-8; monocyte chemotactic protein-1 (MCP-1); macrophage inflammatory protein1β (MIP-1β) and chemokine (C-X-C motif) ligand 16 (CXCL16); intestinal-fatty-acid-binding protein (ifabp), a biomarker of enterocyte damage and zonulin, a biomarker of intestinal permeability. In addition, intestinal microbiota composition was correlated with immunological biomarkers.', 'Infants with colic had increased concentrations of IL-8, MCP-1 and MIP-1β in serum as compared with healthy children. All the other immunological biomarkers were comparable between the groups. Fecal levels of Clostridium leptum correlated negatively with the pro-inflammatory markers MCP-1 (r\u200a=\u200a-0.44, p\u200a=\u200a0.02), MIP-1β (r\u200a=\u200a-0.43, p\u200a=\u200a0.02) and TNF-α (r\u200a=\u200a-0.38, p\u200a=\u200a0.04). In addition, Clostridium coccoides group levels correlated negatively with MCP-1 (r\u200a=\u200a-0.43, p\u200a=\u200a0.02) and Bifidobacterium breve levels positively with CXCL16 (r\u200a=\u200a0.38, p\u200a=\u200a0.04).'] Is infantile Colic Associated with Low-grade Systemic Inflammation?