Umbilical cord blood immune cell profiles in relation to the infant gut microbiome.

During infancy, the interplay between the developing immune system and the microbiome is critical. We examined whether blood immune cell composition at birth in the umbilical cord (inferred by DNA methylation profiling) related to the early infant gut microbiome (assessed by 16S rRNA gene sequencing) among 73 infants in the New Hampshire Birth Cohort Study. We used generalized estimating equations and controlled for false discovery rate to select microbial taxa associated with immune cells. We found associations between the infant gut microbiome and immune cells, including a positive association between B cells and , a negative association between natural killer cells and , and a positive association between granulocytes and . Our findings give clues that immune profiles at the time of birth as measured in umbilical cord blood are associated with the development of the gut microbiome in early life.