The findings, based on over 6,500 children with a genetic risk of coeliac disease, challenges currently-held assumptions about coeliac development and maternal nutrition.
“The results found no indication that use of vitamin D, omega-3 fatty acids (FA) and iron (Fe) supplements during pregnancy confers risk for coeliac disease in children,” the study concluded.
“The nutrients absorbed from maternal supplements not only participate in the programming of the immune system in the offspring but also affect the composition of their gut microbiota.”
Despite its importance, the maternal diet’s role in the risk for coeliac disease in the offspring has not been an area of great focus.
It is generally accepted that foetal exposure to nutrients and dietary components may affect disease risk by influencing the development of the immune system and intestinal microbiota.
One study found an increased risk of coeliac disease in children whose mothers used iron supplements during pregnancy in children in a large Norwegian prospective cohort.
TEDDY project
The children were part of a series of studies known as the TEDDY project (The Environmental Determinants of Diabetes in the Young).
This international multicentre observational study follows children from birth until the age of 15 years in the search for environmental factors involved in both type 1 diabetes and coeliac disease.
Located in Finland, Germany and Sweden, the study selected 6627 children that had been screened for transglutaminase antibodies (tTGA), an indicator of coeliac disease.
Of those enrolled children, 1136 developed coeliac disease autiimmunity (CDA) at a median 3·1 years of age (range 0·9–10) and 409 developed coeliac disease (CD) at a median 3·9 years of age (range 1·2–11).
Use of supplements containing vitamin D, omega-3 FA and Fe was recalled by 66, 17 and 94 % of mothers, respectively, at 3–4 months postpartum.
“Mothers giving birth to children developing coeliac disease were found to have different pregnancy serum cytokine profile than mothers of healthy children, suggesting that the prenatal environment may have an impact on the autoimmunity status in the offspring,” the study said.
“During pregnancy, women are encouraged to optimise their diet to meet increased needs for most nutrients. Those with poor diet quality, Fe-deficiency anaemia, vegans, smokers and women carrying two or more foetuses are recommended to boost their intake with a dietary supplement.”
Gluten debate
With ‘trendy’ gluten-free products on the rise among people not diagnosed with coeliac disease, the subject of gluten’s links to health is a hotly debated one.
The onset of coeliac disease may occur at any age, which makes the need to identify the triggers even more pressing.
Results of this latest study only add to the argument as to how much and how fast gluten can be increased during the baby’s development.
“The environmental trigger, or triggers, for the disease is also not yet known, something that constitutes “the most gaping of holes in our knowledge about [the] disease”, according to Euromonitor.
“Researchers in the field have their theories, of course […]. Stipulated triggers include being bottle fed, having been born via caesarean section, too-early exposure to gluten during weaning, and the introduction of dietary gluten too late during childhood, and exposure to antibiotics.”
The study commented nutrients absorbed from maternal supplements could participate in the programming of the immune system in the offspring as well as affecting the composition of their gut microbiota.
Previous human studies have shown that Fe supplementation may induce changes in the maternal gut microbiota that can be transferred to the infant.
This may promote a less-favourable bacterial colonisation of the newborn’s digestive system.
Despite the researcher’s theories they said that, “the hypothesis that dietary supplements act on the foetus’s immune system and induce tolerance to food antigens during infancy remains unknown.”
Source: British Journal of Nutrition
Published online ahead of print: doi.org/10.1017/S0007114517000332
“Maternal use of dietary supplements during pregnancy is not associated with coeliac disease in the offspring: The Environmental Determinants of Diabetes in the Young (TEDDY) study.”
Authors: Jimin Yang, Roy Tamura et al.