SAN FRANCISCO—Maternal inflammatory bowel disease is associated with an increased risk for IBD in children, but it may be possible to modify this risk, according to Inga Peter, PhD, who spoke on the topic at the 2025 Crohn’s & Colitis Congress.
“There is accumulating evidence suggesting that early-life exposures are associated with increased risk of [IBD] later in life,” according to Dr. Peter, a professor of genetics at the Icahn School of Medicine at Mount Sinai, in New York City. “Strategies implemented during this critical period may offer a possibility to modulate disease risk,” Dr. Peter added.
“Maternal IBD is associated with lower bacterial diversity and higher fecal calprotectin levels in the child, independent of genetic predisposition,” Dr. Peter said, adding that an altered microbiome may affect immune system development and potentially increase IBD risk.
Dr. Peter also noted that early exposure to some heavy metals and to per- and polyfluoroalkyl substances, sometimes called “forever chemicals,” is linked with an increased IBD risk.
To ascertain whether diet may help normalize the intestinal microbiota in the mother and child, Dr. Peter and her co-investigators conducted the 10-week MELODY dietary intervention study, in which 99 pregnant women with Crohn’s disease and 99 controls, 37 of them with CD, followed the Mediterranean-inspired IBD anti-inflammatory diet from 27 to 29 weeks of gestation through delivery. The investigators sought to assess microbiome diversity and disease activity in the mothers postpartum as well as calprotectin and microbiome diversity in babies at various time points up to one year.
Some preliminary findings from the study showed fecal calprotectin levels were higher after the intervention in women who did not follow the diet, although there was no difference six and 12 months after delivery. They also found a trend toward lower fecal calprotectin levels in infants whose mothers were on the diet, but it was not statistically significant. While detailed analyses of the microbiota diversity are pending, infants whose mothers were on the diet had a significantly higher abundance of Bifidobacterium breve and much lower abundance of Escherichia coli and Proteobacteria at six months, suggesting that maternal diet during the third trimester of pregnancy may affect microbiota colonization in the offspring.
Dr. Peter also presented data showing that maternal CD was a better predictor of infants’ fecal calprotectin levels than their genetic risk burden or polygenic risk score based on an array of genes. “Maternal diagnosis was, by far, a superior predictor of baby calprotectin levels than genetic predisposition, and that remained the same after adjustment for all other covariates,” Dr. Peter said.
However, she said, when they looked at babies with a polygenic risk score in the top 10%, they found that this group also had heightened fecal calprotectin levels, regardless of the mothers’ CD status, and altered microbiota composition, with some bacterial strains previously linked to IBD. “Maternal Crohn’s disease, polygenic risk score and microbiota diversity independently predicted the highest level of calprotectin during early life,” Dr. Peter explained.
Ultimately, she added, while the goal is to identify babies at increased risk who could benefit from a preventive intervention, it remains to be determined whether higher CD symptom burden, intestinal inflammation and colonization with certain microbiota early in life increase risk of future disease.
Lea Ann Chen, MD, who attended the session, praised the work but noted that far more research is still needed. “These are [projects] that have to be done,” said Dr. Chen, an assistant professor of medicine at Rutgers University, in New Brunswick, N.J. “It’s just so slow because you identify these babies when they’re born, and then you have to follow them for years and years, and that’s a very expensive endeavor.”
—Jim Kling
Drs. Chen and Peter reported no relevant financial disclosures.
This article is from the May 2025 print issue.