Systematic review links gut dysbiosis and AhR/TLR4 pathway alterations to non-IgE-mediated cow's milk allergy in infants.

A systematic review with integrated multi-omics corroboration examined 39 studies focusing on infants between 0 and 3 years of age diagnosed with physician-confirmed non-IgE-mediated cow's milk allergy. The investigation sought to clarify a potential pathogenic axis driven by dysbiosis that involves the aryl hydrocarbon receptor (AhR) and Toll-like receptor 4 (TLR4). No comparator group was explicitly defined in the integrated analysis, and the setting of the original studies was not reported.

The main results indicated a specific gut dysbiosis signature characterized by decreased Bifidobacterium and increased Enterobacteriacea. Additionally, microbial AhR ligands and the TLR4 pathway were found to be reduced. The review noted that the absolute numbers and specific effect sizes for these changes were not reported in the source data. Statistical significance values and confidence intervals were also not provided for these specific outcomes.

Safety and tolerability data, including adverse events, serious adverse events, discontinuations, and general tolerability, were not reported for the interventions or exposures identified. A key limitation highlighted is that the underlying pathogenesis of the condition is still poorly understood. Consequently, the current evidence suggests an association between gut dysbiosis and immune dysregulation but does not confirm a definitive pathogenic axis. This uncertainty impedes the development of targeted nutritional strategies for this population.