The impact of fish oil and/or probiotics on serum fatty acids and the interaction with low-grade inflammation in pregnant women with overweight and obesity: secondary analysis of a randomized controlled trial.

N-3 long-chain polyunsaturated fatty acids (LC-PUFAs) and probiotics are generally considered to induce health benefits. The objective was to investigate 1) the impact of fish oil and/or probiotics on serum fatty acids (sFAs), 2) the interaction of sFAs with low-grade inflammatorion and 3) the relation of sFAs to the onset of gestational diabetes mellitus (GDM). Pregnant women with overweight/obesity were allocated into intervention groups with fish oil+placebo, probiotics+placebo, fish oil+probiotics or placebo+placebo in early pregnancy (fish oil: 1.9g docosahexaenoic acid (DHA) and 0.22g eicosapentaenoic acid (EPA), probiotics: Lacticaseibacillus rhamnosus HN001 and Bifidobacterium animalis ssp . lactis 420, 10 10 CFU, each daily). Blood samples were collected in early (n=431) and late pregnancy (n=361) for analysis of fatty acids in serum phosphatidylcholine (PC), cholesteryl esters (CEs), triacylglycerols (TAGs) and non-esterified fatty acids (NEFAs) with gas chromatography and high sensitivity C-reactive protein (hsCRP) and GlycA by immunoassay and NMR spectroscopy, respectively. GDM was diagnosed according to 2h 75g OGTT. ClinicalTrials.gov, NCT01922791. EPA in PC, CEs and TAGs, and DHA in PC, CEs, TAGs and NEFAs were higher in fish oil and fish oil+probiotics groups compared to placebo. EPA in serum NEFAs was lower in women receiving probiotics compared to women not receiving. Low-grade inflammation was inversely associated with n-3 LC-PUFAs which were related to an increased risk for GDM. Fish oil and fish oil+probiotics consumption increase serum n-3 LC-PUFAs in pregnant women with overweight/obesity. Although these fatty acids were inversely related to inflammatory markers, n-3 LC-PUFAs were linked with an increased risk for GDM.