Contact
Sigurlaug Skírnisdóttir
Project Manager
sigurlaug.skirnisdottir@matis.is
Summary:
The infant gut microbiome plays a critical role in the early development of the immune system, brain function, metabolism, and defense against pathogens. However, data from underrepresented populations, like Iceland, with its distinct dietary and lifestyle habits, remain limited. This paper presents the initial findings from the Icelandic Diet and the Infant Gut Microbiome Development (IceGut) study. Fecal samples were collected at multiple time points, representing 328 unique study identifiers, with one to five samples per child, from before the introduction of solid foods up to 5 years of age, and postpartum samples from 214 mothers. Microbial composition and predicted functional potential were assessed using 16S rRNA gene sequencing. Children in the cohort followed typical gut microbiome maturation, but at 1 year of age, they showed a notably higher relative abundance of Blautia than reported in comparable cohorts. This time point marked a transition in both taxonomic composition and predicted functional gene counts. By 5 years, the children had higher observed richness than their mothers but lower Shannon and Simpson diversities. At 2 and 5 years, and in the mothers, samples positive for archaea had significantly higher alpha diversity than samples that tested negative for archaea. Mothers with gestational diabetes mellitus (GDM) exhibited a higher relative abundance of Blautia but a lower alpha diversity. The variance in offspring gut microbiome explained by maternal GDM became progressively stronger over time, being significant at the age of 5 and explaining 2.5% of the variance.