Provision of Lipid-Based Nutrient Supplements to Mothers During Pregnancy and 6 Months Postpartum and to Their Infants from 6 to 18 Months Promotes Infant Gut Microbiota Diversity at 18 Months of Age but Not Microbiota Maturation in a Rural Malawian Setting: Secondary Outcomes of a Randomized Trial

Abstract

Background: Diet may alter the configuration of gut microbiota, but the impact of prenatal and postnatal nutritional interventions on infant gut microbiota has not been investigated.

Objective: We evaluated whether providing lipid-based nutrient supplements (LNSs) to mother-infant dyads promotes a more diverse and mature infant gut microbiota, compared to maternal supplementation with multiple micronutrients (MMN) or iron and folic acid (IFA).

Methods: We enrolled 869 pregnant women in a randomized trial in Malawi. There were 3 study groups, with women receiving 1 MMN capsule daily during pregnancy and 6 mo postpartum, or 1 LNS sachet (20 g) daily during pregnancy and 6 mo postpartum, or 1 IFA capsule daily (during pregnancy) then a placebo daily (postpartum). Infants in the LNS group received LNS from 6 to 18 mo; infants in the other groups did not receive supplements. The infants' fecal microbiota were characterized by PCR amplification and sequencing of the bacterial 16S rRNA gene (variable region 4). The primary outcomes were microbiota α diversity and maturation [as microbiota-for-age z score (MAZ)]. Specific associations of taxa with intervention were established with indicator species analysis (ISA).

Results: Primary outcomes did not differ between IFA and MMN groups, so these groups were combined (IFA + MMN). Mean ± SD α diversity was higher in the LNS group at 18 mo for Shannon index [3.01 ± 0.57 (LNS) compared with 2.91 ± 0.60 (IFA + MMN), P = 0.032] and Pielou's evenness index [0.61 ± 0.08 (LNS) compared with 0.60 ± 0.09 (IFA + MMN), P = 0.043]; no significant differences were observed at 1, 6, 12, or 30 mo. MAZ and β diversity did not differ at any age. We found 10 and 3 operational taxonomic units (OTUs) positively associated with LNS and IFA + MMN, respectively; however, these associations became nonsignificant following false discovery rate correction at 10%.

Conclusions: Prenatal and postnatal LNS intake promoted infant gut microbiota diversity at 18 mo, after 12 mo of child supplementation, but did not alter microbiota maturation. This trial was registered at clinicaltrials.gov as NCT01239693.

Keywords: gut microbiota; infants diet; lipid-based nutrient supplements; microbiota diversity; multiple micronutrients.

FIGURE 1

Flow diagram of recruitment, enrollment, and follow-up of Malawian women and their infants who participated in the International Lipid-Based Nutrient Supplements Project. *Death and drop out numbers are cumulative. LNS, lipid-based nutrient supplement.

FIGURE 2

Shannon index (A) and Pielou's index (B) at 6 mo as a function of season at the time of sample collection by intervention group. Sample sizes for IFA + MMN compared with LNS groups were as follows: warm-wet season (246 compared with 118), cool-dry season (129 compared with 71), and hot-dry season (101 compared with 47). *IFA + MMN and LNS groups differ, P < 0.05. **IFA + MMN and LNS groups differ, P < 0.01. IFA, iron and folic acid; LNS, lipid-based nutrient supplement; MMN, multiple micronutrients.

FIGURE 3

Species richness (A) and phylogenetic diversity (B) at 12 mo as a function of season at the time of sample collection by intervention group. Sample sizes for IFA + MMN compared with LNS groups were as follows: warm-wet season (246 compared with 118), cool-dry season (129 compared with 71), and hot-dry season (101 compared with 47). *IFA + MMN and LNS groups differ, P < 0.05. IFA, iron and folic acid; LNS, lipid-based nutrient supplement; MMN, multiple micronutrients.

FIGURE 4

Shannon index at 30 mo as a function of baseline asset index percentile by intervention group. Sample sizes for IFA + MMN compared with LNS groups were as follows: below 90th percentile (351 compared with 170) and above 90th percentile (26 compared with 20). ***IFA + MMN and LNS groups differ, P < 0.001. IFA, iron and folic acid; LNS, lipid-based nutrient supplement; MMN, multiple micronutrients.

FIGURE 5

Indicator species analysis at genus level by intervention at 1 mo, 6 mo, 12 mo, 18 mo, and 30 mo. The size of each square is proportional to the size of the indicator species value metric. Sample sizes at each time point for the IFA + MMN compared with LNS groups were as follows: 1 mo (225 compared with 106), 6 mo (347 compared with 168), 12 mo (419 compared with 211), 18 mo (414 compared with 208), and 30 mo (382 compared with 193). () IFA + MMN and LNS groups differ, P < 0.05 (before the Benjamini-Hochberg correction). IFA, iron and folic acid; LNS, lipid-based nutrient supplement; MMN, multiple micronutrients.