# Relationship between the dietary inflammatory index and immune function during pregnancy – A secondary analysis of the MicrobeMom2 Study

## TL;DR

This study explores how a pro-inflammatory diet in late pregnancy is linked to changes in immune markers, which could affect pregnancy outcomes.

## Contribution

The study is the first to link the energy-adjusted dietary inflammatory index (E-DII) with specific immune markers in late pregnancy.

## Key findings

- Higher E-DII scores were associated with increased serum C3 complement protein and IL-17 levels.
- A pro-inflammatory diet was linked to reduced IL-10 secretion from PBMCs after stimulation.
- Dietary patterns may influence maternal immune function and potentially impact pregnancy complications.

## Abstract

The maternal immune system requires careful regulation during pregnancy to prevent complications such as preeclampsia and prematurity. Inflammatory immune states may be linked to maternal diet throughout pregnancy. Although gestational changes in cytokines are well-documented, the association with the inflammatory potential of diet has not been robustly explored. This study investigates the associations between maternal dietary inflammatory potential, measured by energy adjusted dietary inflammatory index (E-DII) in late pregnancy (28-32 weeks’ gestation).

E-DII was calculated using 6-month food frequency questionnaires completed by pregnant mothers at 28–32 weeks’ gestation. Serum cytokine levels from maternal blood samples were measured using Cobas® and ProteinSimple ELLA immunoassay, while PBMC derived cytokine levels were assessed using BioLegend LEGENDplex™.

The study included 68 pregnant women, with a mean age (SD) at recruitment of 33.01(4.6) years and median BMI (IQR) of 24.95 (21.87, 27.57) kg/m2. There was a positive association between E-DII and serum C3 complement protein in late pregnancy [β =0.057, p = 0.043]. A positive association between maternal E-DII and late pregnancy serum IL-17 levels was also observed [β = 0.156, p = 0.011]. A more pro-inflammatory diet in late pregnancy indicated by higher E-DII scores was associated with lower IL-10 secretion from PBMCs stimulated with anti-CD3/28/2 [β = −0.232, p = 0.049].

Diet may hold potential to promote optimal maternal inflammatory states. These data may inform nutritional guidelines to reduce pregnancy related complications, especially for mothers with higher background metabolic risk, such as those living with obesity.