Breastmilk microbiota and its association with infant iron deficiency anaemia: A 16S rRNA metagenomic study in Peruvian mothers cohort

Anaemia is one of the most important public health challenges in developing countries. The global burden is estimated at 1.8 billion people, affecting approximately 30% of all children. Despite the implementation of multiple strategies over several decades, up to 42.5% of children under 3 years of age suffer anaemia in rural areas of Peru. We studied the microbiota of breastmilk (hBM) from mothers with children under the age of 1 and analysed its association with their iron deficiency anaemia. 46 mother-child pairs were recruited from Talara, a town on the northern coast of Peru and classified according to the clinical status of the children. Children with anaemia were also tested for ferritin level to classify them as iron deficiency anaemia (IDA) or non-iron deficiency anaemia (non-IDA). hBM samples were taken from the mothers after careful instruction to reduce the risk of sample contamination and the microbiome was analyzed using 16S rRNA sequencing. Streptococcus and Staphylococcus were the predominant genera, with 90% of bacterial abundance being explained by 14 genera. Alpha diversity analysis showed that hBM from mothers of children with non-IDA had higher levels of bacterial richness than hBM from healthy (p < 0.01) and IDA (p < 0.05) participants. Principal coordinates analysis did not yield differential clusters but showed a disparity in the spread of samples for non-IDA group when compared with the other groups. IDA group showed higher burden of Corynebacterium, Acinetobacter, Paludibacter and Nitrospira, while exhibiting a trend towards a lower burden of Streptococcus. No statistically significant differences were identified on demographic characteristics. This study suggests that hBM microbiota may differ in mothers of children with IDA and non-IDA, highlighting the necessity of further in-depth research to elucidate potential factors associated with its pathogenesis.