Location: Immunity and Disease Prevention ResearchTitle: Neonatal vitamin A supplementation and vitamin A status are associated with gut microbiome composition in Bangladeshi infants in early infancy and at two years of age
|HUDA, NAZMUL - International Centre For Diarrhoeal Disease Research|
|AHMAD, SHAIKH - International Centre For Diarrhoeal Disease Research|
|KALANETRA, KAREN - University Of California, Davis|
|TAFT, DIANA - University Of California, Davis|
|ALAM, MD - International Centre For Diarrhoeal Disease Research|
|KHANAM, AFSANA - International Centre For Diarrhoeal Disease Research|
|RAQIB, RUBHANA - International Centre For Diarrhoeal Disease Research|
|UNDERWOOD, MARK - University Of California, Davis|
|MILLS, DAVID - University Of California, Davis|
Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2019
Publication Date: N/A
Interpretive Summary: Vatiamin A deficiency affects the intestinal immune system which, in turn, can affect colonizaiton of the intestinal tract by commensal bacteria. To determine if treatment of newborn infants with vitamin A increased colonization by the beneficial commensal Bifidobacterium longum subspecies infantis (also known as B. infantis) ARS scientists worked with colleagues to conduct an intervention trial among healthy infants in Bangladesh, where vitamin A deficiency is common. Between 6 and 15 w of age the study found that B. infantis was higher in infants receiving exclusive breastfeeding (as compared to infants receiving other supplemental liquids), was higher in girls than boys, and was higher in those receiving vitamin A supplementation (compared to those receiving placebo). However, this increase due to vitamin A was seen only in boys, perhaps because girls already had higher B. infantis levels. These differences were no longer evident when infants were 2 y of age. In summary, vitamin A supplementation may increase B. infantis levels in infants at risk of vitamin A deficiency. Such an increase may be one means by which adequate vitamin A status improves the health of infants.
Technical Abstract: : Colonization of the infant gut with commensal bacteria is an important determinant of health in infancy and later in life that is influenced by environmental and host factors. Vitamin A deficiency impairs mucosal immunity and the integrity of mucosal epithelial surfaces. Thus, vitamin A status in early infancy may affect appropriate colonization of the infant gut. In this study we examined the hypothesis that vitamin A supplementation (VAS) within 48 h of birth would increase the relative abundance of Bifidobacterium, and decrease the relative abundance of Enterobacteriaceae, in Bangladeshi infants at risk of deficiency. As secondary goals, we examined the effect of VAS, and of vitamin A status on the relative abundance of all bacterial taxa, with adjustment for multiple comparisons. This study (ClinicalTrials.gov identifier NCT02027610) examines the relative abundance of stool bacteria at 6, 11 and 15 w of age in early infancy, and again at 2 y of age, in infants previously randomized to vitamin A or placebo treatment within 48 h of birth (ClinicalTrials.gov Identifier: NCT01583972). The study was conducted at the Maternal and Child Health Training Institute (MCHTI) in Dhaka, Bangladesh. 306 infants (153 male) were enrolled, stool samples from 280 were available at 6 w, and from 249 at 2 y. A single, oral dose of 50,000 IU vitamin A, or identical placebo, was administered within 48 h of birth. Plasma retinol was measured at 15 w and 2 y of age. Relative abundance of bacteria assessed using 16S rRNA gene sequencing at 6 w, 11 w, 15 w and 2 y; and using a terminal restriction fragment-length polymorphism (T-RFLP) assay to identify Bifidobacterium longum subsp. infantis, B. longum subsp. longum, and other species at 6 w. Bifidobacterium abundance in early infancy (6-15 w of age) was higher in boys who received vitamin A supplementation compared to placebo. No treatment effect was seen in girls. Bifidobacterium abundance was higher in girls than boys and in infants with exclusive vs. non-exclusive breastfeeding. Vitamin A supplementation did not affect the relative abundance of Enterobacteriaceae.