Nutritional Status and Fecal Microbiota in School Children from the Galapagos and the Andean Region

Schoolchildren from the Galapagos and the Andean region present the worst indices of malnutrition in Ecuador and are exposed to distinctive food and water insecurity. We compared the nutritional status, the fecal microbiota composition of schoolchildren from the Galapagos (n = 51; 8.88 ± 2.15 years) and the Andean region (n = 114; 8.69 ± 1.83 years). Children had a nutritional evaluation and provided fecal samples for microbiota analysis by 16S rRNA gene sequencing. Excess weight was more prevalent in Galapagos (41.18%) than in the Andes (24.5%). Additionally, intestinal parasitosis was more prevalent in children from the Andes (76.4%) than in Galapagos (13.0%). Species richness was lower in fecal samples of children from the Galapagos than those from the Andes (Chao1 index p = 0.001). Beta-diversity metrics also showed significant differences between these samples. Bacteroidota and Proteobacteria were enriched in the microbiota of Galapagos children, whereas Firmicutes A and Cyanobacteria were enriched in the Andean children. At the genus level, the top 3 genera present in schoolchildren from the Galapagos were Bacteroides, Phocaeicola, and Escherichia, while in children from the Andes were Cryptobacteroides, Prevotella, and Clostridium. Cyanobacteria were inversely associated with BMI z-score in the Galapagos region (q = 0.009), while, Firmicutes D had a direct relationship with BMI z-score in children from the Andes (q = 0.05). At the genus level, only Butyrivibrio was inversely associated with BMI z-score in children of the Galapagos (q = 0.04). We conclude that schoolchildren with different degrees of malnutrition from two distinct geographical areas have dissimilar fecal microbiota characteristics.