Maternal and cord blood vitamin D level and the infant gut microbiota in a birth cohort study

Maternal vitamin D status during pregnancy and infant's gut microbiota: a prospective cohort study

Objectives

To prospectively explore the association of maternal serum 25(OH)D levels with the infant's gut microbiota in Chinese populations, and to evaluate its potential influence on the dynamic change patterns of offspring's gut microbiota from 1 to 6 months old.

Methods

Eighty-seven mother-infant dyads (vitamin D insufficient group vs. normal group = 59 vs. 28) were included in this longitudinal study. Two fecal samples were collected for the included infant at home by the parents at 1 month of age ("M1 phase") and 6 months of age ("M6 phase"). Gut microbiota were profiled by 16S rRNA gene sequencing. We performed mixed effects models on alpha diversity metrics, PERMANOVA tests on beta diversity distances, and linear discriminant analysis (LDA) to identify differently abundant taxa.

Results

We observed significantly lower Pielou's evenness and Shannon diversity in the vitamin D insufficient group in the M6 phase (p = 0.049 and 0.015, respectively), but not in the M1 phase (p > 0.05), and the dynamic changes in alpha diversity from 1 to 6 months old were significantly different according to maternal vitamin D status (p < 0.05). There were also significant differences in gut microbiota composition between the vitamin D insufficient group and normal group, both in the M1 and M6 phases (LDA score > 2.0, p < 0.05). Moreover, among the predicted metagenome functions, pathways related to amino acid biosynthesis, starch degradation, and purine nucleotides biosynthesis were enriched in the vitamin D insufficient group.

Conclusion

Our findings highlight that maternal vitamin D status plays a pivotal role in shaping the early-life gut microbiota of the next generation.

Nutrition during pregnancy: Influence on the gut microbiome and fetal development

Pregnancy is a finely tuned process, with the health and well-being of the developing fetus determined by the metabolic status and dietary intake of the mother. The maternal gut microbiome is remodeled during pregnancy, and this, coupled with the maternal nutrient intake during gestation shapes the production of metabolites that can cross the placenta and affect fetal development. As posited by the Developmental Origins of Health and Disease Hypothesis, such environmental influences can have major effects on the developing organ systems. When occurring at particularly sensitive gestational time points, these developmental programming events can have long lasting effects on offspring adaptation to the postnatal environment, and major health implications later in life. This review will summarize current knowledge on how pregnancy and maternal dietary intake intrinsically and extrinsically modify maternal gut microbiota composition and metabolite production. Further, we will assess how these factors shape the fetal landscape and ultimately contribute to offspring health. DOHaD, fetal development, metabolites, microbiome, nutrition, pregnancy, short-chain fatty acids.

Maternal vitamin D in pregnancy and infant's gut microbiota: a systematic review

Background

An infant's gut microbiome plays a vital role in their health, and various factors can impact their gut microbiota composition. This review aimed to summarize the current knowledge regarding the associations between maternal prenatal supplementation with vitamin D and the composition of infants' gut microbiota.

Method

A comprehensive systematic search was done on Web of Science, Scopus, PubMed, ScienceDirect, and Google Scholar databases without date restrictions until December 2022 using relevant keywords. All relevant original articles in English were eligible for the present review.

Results

Eight articles (two mice, three randomized clinical trials, and three cohort studies) were included in this review. The included mice studies reported that maternal prenatal vitamin D supplementation significantly affects the offspring's gut microbiome composition (such as enhancing the abundance of colonic Bacteroides). Moreover, the included cohort studies revealed a significant association between maternal supplementation with vitamin D during pregnancy and the infant's gut microbiome. However, one-third of clinical trials indicated that vitamin D levels in utero could influence the colonization of the microbial community in the infant's gut.

Conclusion

The findings of this review revealed that maternal vitamin D supplementation during pregnancy was linked to an infant's gut microbiome and could impact their gut microbiota composition. However, more studies are warranted to confirm these results.

Immunomodulatory Role of Vitamin D on Gut Microbiome in Children

Vitamin D plays a role in regulating the immune system and can be linked to the alteration of the gut microbiome, which leads to several immunological diseases. This systematic review aims to explore the relationship between Vitamin D and children's gut microbiome, as well as its impact towards the immune system. We have systematically collated relevant studies from different databases concerning changes in the gut microbiome of children from infants to 18 years old associated with Vitamin D and the immunological pathways. The studies utilized 16S rRNA sequencing analysis of fecal matter with or without Vitamin D supplementation and Vitamin D levels. Ten studies were selected for the review, among which eight studies showed significant alterations in the gut microbiome related to Vitamin D supplementation or Vitamin D levels. The taxa of the phylum Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria are the most altered in these studies. The alteration of the taxa alters the Th1 and Th2 pathways and changes the immune response. We will discuss how Vitamin D may contribute to the activation of immune pathways via its effects on intestinal barrier function, microbiome composition, and/or direct effects on immune responses. In conclusion, the studies examined in this review have provided evidence that Vitamin D levels may have an impact on the composition of children's gut microbiomes.

Association of Vitamin D Level and Maternal Gut Microbiome during Pregnancy: Findings from a Randomized Controlled Trial of Antenatal Vitamin D Supplementation

Shifts in the maternal gut microbiome and vitamin D deficiency during pregnancy have been associated, separately, with health problems for both the mother and the child. Yet, they have rarely been studied simultaneously. Here, we analyzed the gut microbiome (from stool samples obtained in late pregnancy) and vitamin D level (from blood samples obtained both in early and late pregnancy) data of pregnant women in the Vitamin D Antenatal Asthma Reduction Trial (VDAART), a randomized controlled trial of vitamin D supplementation during pregnancy, to investigate the association of vitamin D status on the pregnant women's microbiome. To find associations, we ran linear regressions on alpha diversity measures, PERMANOVA tests on beta diversity distances, and used the ANCOM-BC and Maaslin2 algorithms to find differentially abundant taxa. Analyses were deemed significant using a cut-off p-value of 0.05. We found that gut microbiome composition is associated with the vitamin D level in early pregnancy (baseline), the maternal gut microbiome does not show a shift in response to vitamin D supplementation during pregnancy, and that the genus Desulfovibrio is enriched in women without a substantial increase in vitamin D level between the first and the third trimesters of pregnancy. We conclude that increasing the vitamin D level during pregnancy could be protective against the growth of sulfate-reducing bacteria such as Desulfovibrio, which has been associated with chronic intestinal inflammatory disorders. More in-depth investigations are needed to confirm this hypothesis.

Association of vitamin D level and maternal gut microbiome during pregnancy: Findings from a randomized controlled trial of antenatal vitamin D supplementation

Shifts in the maternal gut microbiome and vitamin D deficiency during pregnancy have been associated, separately, with health problems for both the mother and the child. Yet, they have rarely been studied simultaneously. Here, we analyzed gut microbiome (from stool samples obtained in late pregnancy) and vitamin D level (from blood samples obtained both in early and late pregnancy) data of pregnant women in the Vitamin D Antenatal Asthma Reduction Trial (VDAART), a randomized controlled trial of vitamin D supplementation during pregnancy, to investigate the association of vitamin D status on the pregnant women’s microbiome. To find associations we ran linear regressions on alpha diversity measures, PERMANOVA tests on beta diversity distances, and used the ANCOM-BS and Maaslin2 algorithms to find differentially abundant taxa. Analyses were deemed significant using a cut-off p-value of 0.05. We found that gut microbiome composition is associated with the vitamin D level in early pregnancy (baseline), the maternal gut microbiome does not show a shift in response to vitamin D supplementation during pregnancy, and that the genus Desulfovibrio is enriched in women without a substantial increase in vitamin D level between the first and the third trimesters of pregnancy. We conclude that increasing the vitamin D level during pregnancy could be protective against the growth of sulfate-reducing bacteria such as Desulfovibrio , which has been associated with chronic intestinal inflammatory disorders. More in-depth investigations are needed to confirm this hypothesis.

Ruminococcus gnavus: friend or foe for human health

Ruminococcus gnavus was first identified in 1974 as a strict anaerobe in the gut of healthy individuals, and for several decades, its study has been limited to specific enzymes or bacteriocins. With the advent of metagenomics, R. gnavus has been associated both positively and negatively with an increasing number of intestinal and extraintestinal diseases from inflammatory bowel diseases to neurological disorders. This prompted renewed interest in understanding the adaptation mechanisms of R. gnavus to the gut, and the molecular mediators affecting its association with health and disease. From ca. 250 publications citing R. gnavus since 1990, 94% were published in the last 10 years. In this review, we describe the biological characterization of R. gnavus, its occurrence in the infant and adult gut microbiota and the factors influencing its colonization of the gastrointestinal tract; we also discuss the current state of our knowledge on its role in host health and disease. We highlight gaps in knowledge and discuss the hypothesis that differential health outcomes associated with R. gnavus in the gut are strain and niche specific.

The Association between Vitamin D and Gut Microbiota: A Systematic Review of Human Studies

Recent evidence has shown a number of extra-skeletal functions of Vitamin D (VD), primarily involving the immune system. One of these functions is mediated by the modulation of gut microbiota, whose alterations are linked to many diseases. Our purpose is to contribute to the understanding of existing evidence on the association between VD and gastrointestinal microbiota alterations. A systematic review of studies with human subjects has been conducted up to January 2021. We included publications reporting the association between gut microbiota and VD, including VD supplementation, dietary VD intake and/or level of 25(OH)D. We identified 25 studies: 14 were interventional and 11, observational. VD supplementation was found to be associated with a significant change in microbiome composition, in particular of Firmicutes, Actinobacteria and Bacteroidetes phyla. Furthermore, Firmicutes were found to be correlated with serum VD. Concerning alpha and beta diversity, a high nutritional intake of VD seems to induce a shift in bacterial composition and/or affects the species’ richness. Veillonellaceae and Oscillospiraceae families, in the Firmicutes phylum, more frequently decreased with both increasing levels of 25(OH)D and vitamin D supplementation. We found evidence of an association, even though the studies are substantially heterogeneous and have some limitations, resulting sometimes in conflicting results. To further understand the role of VD on the modulation of the gastrointestinal microbiota, future research should be geared toward well-designed animal-based studies or larger randomized controlled trials (RCTs).

Vitamin D and The Gut Microbiota: a Narrative Literature Review

Recently several studies have attempted to investigate the association between vitamin D and microbiota. However, studies have reported inconsistent results. This narrative review aimed to investigate the potential association between vitamin D and microbiota population in the gut by pooling together the results from observational studies and clinical trials. We considered animal and human studies in this field. Several studies have shown the correlation of vitamin D deficiency with microbiota. Furthermore, interventional studies were emerging that vitamin D change the microbiota composition in which leads to an increase in beneficial bacteria, such as Ruminococcaceae, Akkermansia, Faecalibacterium, and Coprococcus while decreases in Firmicutes. Vitamin D could change the microbiota toward decreasing in Firmicutes and increasing in Bacteroidetes. At genera level, vitamin D may connect to some genera of Lachnospiaceae family (e.g., Blautia, Rosburia, Dorea, and Coprococcus). It seems that adequate level of vitamin D is an important factor in improving the composition of the gut microbiota. More studies are needed to confirm possible underling mechanisms.