Bacterial Composition and Metabolic Pathways Differ in Six-Month-Old Infants from Peru and California, USA

The infant gut microbiome rapidly develops with age and is influenced by various factors. The potential influence of an infant's geographical origin on these adaptations should be considered. We compared six-month-old infants from two distinct locations — Iquitos, Peru, and San Diego, California, USA —to identify geography-related differences in infant gut microbiomes. This comparison was conducted by analyzing microbial diversity, composition, and functional phenotype in fecal samples. Beta diversity analysis suggested statistically significant differences in microbial communities between the two infant cohorts. Functional analysis using the PICRUSt2 software revealed an overrepresentation of different bacterial metabolic pathways associated with infant development in both infants from Peru and California. However, taxonomic results showed that the bacteria commonly associated with these metabolic pathways, namely, Faecalibacterium, Lactobacillus, and Bifidobacterium, were more abundant in the infants from Peru than from California. These findings varied in similar patterns between the two cohorts, suggesting a potential difference in the microbiome of the infants from these geographical locations. This highlights the need for further studies to directly uncover and characterize microbial variations between infants from different regions through direct location comparisons between multiple groups as well as data collection in understudied geographical locations and demographics. Ultimately, this may improve the quality of results and encourage further studies on diverse geographical locations and demographics to expand our knowledge on the infant intestinal microbiota and different functional activity, worldwide.