Composition of the microbiota in patients with growth hormone deficiency before and after treatment with growth hormone.

ABSTRACT

INTRODUCTION: Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) have modulatory effects on bowel function and its microbiota. Our aim was to investigate whether low levels of GH and IGF-1 in patients with GH deficiency are associated with changes in gut physiology/integrity as well as in the composition of the gut microbiota. MATERIALS AND METHODS: We conducted a case-control study in 21 patients with GH deficiency, at baseline and after 6 months of GH treatment, and in 20 healthy controls. We analysed changes in anthropometric and laboratory characteristics and bacterial translocation and studied the composition of the microbiome by means of massive 16S rRNA gene sequencing. RESULTS: Growth hormone deficiency was accompanied by a significant increase in serum levels of sCD14, a marker of bacterial translocation (P < .01). This increase was reversed by GH treatment. We did not find any differences in the composition or α- or ß-diversity of the gut microbiota after treatment or between cases and controls. CONCLUSIONS: Our work is the first to demonstrate that the presence of GH deficiency is not associated with differences in gut microbiota composition in comparison with healthy controls, and changes in microbiota composition are also not found after 6 months of treatment. However, GH deficiency and low IGF-1 levels were associated with an increase in bacterial translocation, which had reversed after treatment.