One tenth of US births are preterm, and those infants are at significantly higher risk of developing infections and experiencing sustained inflammatory states predisposing them to inflammatory morbidities throughout life. Breastmilk provides the anti-inflammatory long-chain polyunsaturated, omega-3 PUFA, DHA. Lactating mothers of preterm infants are prescribed supplemental DHA, with levels of 1000 mg/d leading to increased milk DHA concentrations. However, it is not clear if the increase in milk DHA also leads to decreased inflammation in preterm infants. Adams and colleagues conducted a study using milk from mothers of preterm infants to explore the impact of DHA supplementation on mammary gland gene expression and report their results in the June 2022 issue of The Journal of Nutrition.
Mothers of preterm infants were enrolled in a randomized trial and received either 200 mg/d (standard level, n=4) or 1000 mg/d (elevated level, n=5) of DHA. Extracellular mammary epithelial cell mRNA was extracted from the fat layer of milk samples to determine the RNA-seq transcriptome, and determine if there were differences in the patterns of proinflammatory gene expression in milk derived from those mothers consuming the standard or elevated level of DHA.
The 409 differentially expressed genes that were upregulated (5 main groups) included those associated with the biological processes of immune regulation and management of oxidative stress, and those that were downregulated (3 main groups) included those associated with the biological process of immune dysregulation. These observations led the authors to conclude that elevated levels of DHA supplementation modulates expression of inflammation-related genes in the mammary gland, and that these changes would improve the inflammasome profile in milk consumed by preterm infants. They suggest larger clinical trials are needed to determine the potential for greater preterm infant protection that could be derived from elevated maternal DHA intakes.
Joselyn M Adams, Christina J Valentine, Rebekah A Karns, Lynette K Rogers, Masahiko Murase, Grace N Fowler, Laurie A Nommsen-Rivers, DHA Supplementation Attenuates Inflammation-Associated Gene Expression in the Mammary Gland of Lactating Mothers Who Deliver Preterm, The Journal of Nutrition, Volume 152, Issue 6, June 2022, Pages 1404–1414, https://doi.org/10.1093/jn/nxac043.
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