Vitamin D supplementation changes gut microbiome of young infants

Last Updated: 2020-08-26

By Megan Brooks

NEW YORK (Reuters Health) - Vitamin D supplementation leads to some apparently favorable changes in a baby's microbiome, most notably a lower abundance of Megamonas bacteria at three months of age, according to new data from the Canadian Healthy Infant Longitudinal Development (CHILD) study.

"Little is known about Megamonas (genus of Veillonellaceae) in infancy or adulthood, but we previously found this gut microbe to be more common in male infants born to mothers with asthma in the CHILD birth cohort," senior author Dr. Anita Kozyrskyj of the University of Alberta, in Edmonton, told Reuters Health by email.

"Interestingly, maternal history of asthma is also a risk factor for more severe respiratory viral infection in infants. Based on this limited evidence, reduced abundance of Megamonas in the gut following infant vitamin D supplementation would be a healthy thing. Its role definitely merits further investigation," said Dr. Kozyrskyj.

Vitamin D plays an important role in early life, supporting bone metabolism and healthy immune system development. Pregnant and nursing mothers often take vitamin D supplements and the diets of infants are often supplemented with vitamin D via drops or formula.

To better understand the impact of vitamin D supplementation on infant gut microbiota and Clostridioides difficile colonization, the researchers studied fecal samples from 1,157 mother-infant pairs in the CHILD cohort study.

Overall, at an average age of 3.52 months, two-thirds of infants were receiving vitamin D supplements; 75% of exclusively breastfed infants were supplemented with vitamin D.

Among all infants, direct vitamin D supplementation of infants correlated significantly with a lower abundance of Megamonas (Q=0.01) in gut microbiota, independent of feeding mode, the researchers report in Gut Microbes.

Overall, nearly 30% of infants carried C. difficile, with a lower incidence of the bacterium among infants who were exclusively breastfed infants. However, after adjusting for breastfeeding status and other factors, neither infant nor maternal vitamin D supplementation was associated with C. difficile colonization.

However, maternal prenatal consumption of three or more cups of vitamin-D fortified milk per day reduced the likelihood of C. difficile colonization in exclusively breastfed infants by 60% (adjusted odds ratio, 0.40; 95% confidence interval, 0.19 to 0.82), even after taking into account maternal or infant vitamin D supplementation and other factors.

"We know that tolerance of cow's milk in infants and adults has an inhibitory influence on C. difficile colonization. C. difficile is capable of fermenting protein. If more cow's milk protein is absorbed in the upper intestine, less of it will be present in the lower intestine to encourage the growth of C. difficile," Dr. Kozyrskyj told Reuters Health.

"Other studies have reported reduced risk of cow's milk allergy in offspring following maternal intake of vitamin D from food during pregnancy. Fortified milk is a common source of vitamin D. All together, these findings suggest that a pregnancy diet, naturally enriched with vitamin D (that is, vitamin D in food and not supplements), can reduce intolerance to cow's milk and colonization with C. difficile in young children," she added.

The study was supported by the Canadian Institutes of Health Research. The researchers have indicated no relevant disclosures.

SOURCE: https://bit.ly/31pcMz6 Gut Microbes, online August 11, 2020.