The Maternal Diet Index and Offspring Microbiota at 1 Month of Life: Insights from the Mediterranean Birth Cohort MAMI

Background: Maternal diet during pregnancy may play a role in infant health outcomes via the maternal microbiota. We assessed the association of the maternal diet index for the Mediterranean area (MDI-med) with infant gut microbiota at 1 month of life. Methods: The MAMI study is a longitudinal birth cohort in the Mediterranean area. In this work, a cross-sectional study, including 120 mother-infant dyads with available maternal diet and infant microbiota at 1-month-old data, was undertaken. The MDI developed in the US (MDI-US) was adapted for the MAMI cohort (MDI-med). Stratification based on extreme values resulted (22 in the "lower" MDI-med group and 23 in the "upper" group from the mean). Relative microbial abundances and alpha (microbial richness and diversity indexes) and beta diversity (Bray-Curtis distance matrix) were compared between the groups. Results: Higher maternal daily vegetable intake and lower red meat intake were the characteristics of the "upper" MDI-med group. Significantly lower microbial diversity (Shannon and InvSimpson index (p = 0.01)), but no changes in richness (Chao1 index) nor in beta-diversity, using Bray-Curtis distance, were observed in the "upper" group, compared to the "lower" MDI-med group. A higher relative abundance of the Bifidobacterium genus (Actinomycetota phylum) was associated with maternal daily vegetable and yogurt intake. Conclusion: Reduced infant microbial diversity at 1 month of age was associated with "upper" MDI-med scores. Higher maternal intakes of vegetables and yogurt were associated with higher relative abundances of the Bifidobacterium genus in the infant gut. Further studies are needed to understand the link between pregnancy diet, infant microbiota, and health outcomes.

This work was supported by the following: the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC starting grant, no. 639 226); the Spanish Ministry of Science and Innovation (MAMI-Plus ref. PID2022-139475OB-I00); the Joint Action European Joint Programming Initiative “A Healthy Diet for a Healthy Life” (JPI-HDHL)”-FOOD-HYPERSENS call (ECOBIOTIC); and national funding from the Programación Conjunta Internacional (PCI) (ref. PCI2021-122059-2A) from the Spanish Government (Ministry of Science, Innovation, and Universities), LaMaratò-TV3 project (DIM-2-ELI, ref. 2018–27/31). The IATA-CSIC authors also acknowledge the Spanish government MCIN/AEI to the Center of Excellence Accreditation Severo Ochoa (CEX2021-001189-S/MCIN/AEI/10.13039/501100011033). RCR thanks Generalitat-Valenciana for the grant Plan GenT project (CDEIGENT 2020). The authors would like to acknowledge the support from Reckitt Nutrition for their support providing the nutrition grant.

Peer reviewed