Objectives: 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. Because 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.
Methods: In 28 infants with colic and in 12 healthy controls at the age of 1 month, we measured the following serum immunological biomarkers: cytokines interleukin 1β (IL-1β); IL-6; IL-10; tumor necrosis factor α; interferon γ (IFN-γ); chemokines IL-8; monocyte chemotactic protein-1 (MCP-1); macrophage inflammatory protein 1β (MIP-1β) and chemokine (C-X-C motif) ligand 16; and intestinal fatty acid-binding protein, a biomarker of enterocyte damage and zonulin, a biomarker of intestinal permeability. In addition, intestinal microbiota composition was correlated with immunological biomarkers.
Results: 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 proinflammatory markers MCP-1 (r = -0.44, P = 0.02), MIP-1β (r = -0.43, P = 0.02), and tumor necrosis factor α (r = -0.38, P = 0.04). In addition, C coccoides group levels correlated negatively with MCP-1 (r = -0.43, P = 0.02) and Bifidobacterium breve levels positively with chemokine (C-X-C motif) ligand 16 (r = 0.38, P = 0.04).
Conclusions: In addition to gut microbiota alterations, colic in infants is associated with low-grade systemic inflammation. Specific bacterial species beyond conventional probiotics may have anti-inflammatory properties that may help to modulate microbiota and alleviate colic-related inflammation.
Trial registration: ClinicalTrials.gov NCT00167700.