Babies of mothers with inflammatory bowel disease (IBD) have lower gut bacterial diversity and altered bacterial composition like their mothers, compared with control women and their infants, US researchers report.

Family history is the strongest risk factor for developing IBD, but the genetic loci identified so far do not fully explain its heritability. 

Some studies have suggested that mothers may be more likely than fathers to transmit IBD, but it has been unclear whether the maternal microbiome composition during pregnancy is altered in IBD and how it might affect the offspring.

Dr Inga Peter, from Mount Sinai School of Medicine in New York, and her team examined the diversity and taxonomy of the microbiome of 40 pregnant women with and 81 without IBD and their babies, 26 of whom were born to women with IBD.