We analyzed whether gene expression analyses or intestinal permeability (IP) testing could provide biomarkers to describe regulation mechanisms in the intestinal barrier in short bowel syndrome (SBS) patients during adaptive response or treatment with the glucagon-like peptide-2 analog teduglutide. This evidence concerns the gene GCG and macrothrombocytopenia and granulocyte inclusions with or without nephritis or sensorineural hearing loss.