Children with idiopathic short stature have significantly different gut microbiota than their normal height siblings: a case-control study

Abstract

Objectives: To investigate the role of gut microbiota (GM) in pathogenesis of idiopathic short stature (ISS) by comparing GM of ISS children to their normal-height siblings.

Methods: This case-control study, conducted at the Schneider Children's Medical Center's Institute for Endocrinology and Diabetes between 4/2018-11/2020, involved 30 pairs of healthy pre-pubertal siblings aged 3-10 years, each comprising one sibling with ISS and one with normal height. Outcome measures from fecal analysis of both siblings included GM composition analyzed by 16S rRNA sequencing, fecal metabolomics, and monitoring the growth of germ-free (GF) mice after fecal transplantation.

Results: Fecal analysis of ISS children identified higher predicted levels of genes encoding enzymes for pyrimidine, purine, flavin, coenzyme B, and thiamine biosynthesis, lower levels of several amino acids, and a significantly higher prevalence of the phylum Euryarchaeota compared to their normal-height siblings (p<0.001). ISS children with higher levels of Methanobrevibacter, the dominant species in the archaeal gut community, were significantly shorter in stature than those with lower levels (p=0.022). Mice receiving fecal transplants from ISS children did not experience stunted growth, probably due to the eradication of Methanobrevibacter caused by exposure to oxygen during fecal collection.

Discussion: Our findings suggest that different characteristics in the GM may explain variations in linear growth. The varying levels of Methanobrevibacter demonstrated within the ISS group reflect the multifactorial nature of ISS and the potential ability of the GM to partially explain growth variations. The targeting of specific microbiota could provide personalized therapies to improve growth in children with ISS.

Keywords: children; germ-free mice; gut metabolome; gut microbiota; idiopathic short stature; methanobrevibacter.

Figure 1

Children with ISS display distinct microbiome characteristics compared to their normal-height siblings. (A) Principal coordinates analysis (PCoA) based upon the Unweighted UniFrac matrices of fecal samples collected from children with ISS and their normal-weight and -height siblings. Each dot represents an individual, colored by the experimental group. (B) Taxonomic cladogram illustrating the most differentially enriched taxa using linear discriminant analysis Effect Size (LEfSe) analysis. (LDA >2). Groups are identified by the different colors. (C) Relative abundance of Methanobrevibacter within the 3 groups (controls and the 2 subpopulations of the ISS group, (**P <.001). (D) Computed Linear Discriminant Analysis (LDA) scores for the differentially enriched microbial metabolic pathways using PICRUSt2 analysis. (LDA >2), C-control, S-ISS.

Figure 2

Metabolic analysis revealed significant differences in amino acid levels between ISS subgroup S2 and its controls.

Figure 3

Effect of fecal transplantation on murine weight, bone length and EGP height. The effect of fecal transplantation from children with ISS (short) compared to their normal height siblings (normal) on animals’ (A) weight. (B) Tibia and humerus length, (C) EGP height. Mean± SD values are shown.