Role of GFAP, IL-6 and EEG in Gut-Brain Nexus

Abstract

The gut-microbiota-brain axis has significant clinical implications but the extent of influence and mechanisms of communication between different systems remain uncertain. The interplay between different brain areas, peripheral nerves, enteric nervous system, immune mediators, gut metabolites, microbiota and pathogens has not been studied in detail in pediatric population. In this single-center retrospective observational analytic study, serum Glial Fibrillary Acidic Protein (GFAP) levels were assessed to quantify neuronal injury in different clinical conditions. In all three groups, the mean GFAP levels were detectable but only subjects with systemic involvement and bacterial etiology showed significantly raised serum GFAP. Secondly, serum Interleukin-6 (IL-6) and serum GFAP levels demonstrated a strong correlation suggesting a potential key role of IL-6 as mediator in gut-brain communication. Finally, electroencephalographic (EEG) assessment of all subjects was carried out as a surrogate for cerebral dysfunction. An interesting and probably novel, sero-electrical correlation was found between serum GFAP levels and specific rhythms of brain EEG in general linear statistical modeling. In summary, this research project was able to highlight neuronal injury in gastrointestinal conditions, identify IL-6 as a potential key mediator of gut-brain communication and present first evidence in favor of a sero-electrical correlation that may have critical clinical implications.