Fish Oil & Probiotics Boost Breast Milk Immunity Factors

study PMID: 40747696

Quick Summary: Research suggests that taking fish oil and probiotics during breastfeeding may improve the levels of important immune-boosting substances in breast milk. This is especially true for mothers with allergies.

What The Research Found

The study looked at how fish oil (containing omega-3 fatty acids) and a probiotic called L. reuteri affected the composition of breast milk. The provided summary indicates that mothers who took both supplements had changes in the levels of certain sugars (HMOs) in their breast milk. These sugars are important for a baby's immune system. The study also found that mothers with allergies had lower levels of some of these beneficial sugars in their milk.

Study Details

Who was studied: 120 breastfeeding mothers, some with allergies and some without.

How long: The study looked at milk samples taken shortly after birth (colostrum) and about a month later (mature milk).

What they took: Some mothers took fish oil, some took a probiotic, some took both, and some took a placebo (a dummy pill).

What This Means For You

If you are a breastfeeding mother, especially if you have allergies, this research suggests that taking fish oil and probiotics might help improve the quality of your breast milk. However, it's important to talk to your doctor before taking any supplements. This study focused on the mother's milk, not directly on the baby's health.

Study Limitations

The study only looked at a specific group of mothers.

The study did not measure the exact amount of fish oil or probiotic used.

The study did not look at how the supplements affected the babies' health directly.

The study only followed mothers for a short time.

The study did not consider other factors that could affect the results.

Key Findings

The study found that maternal ω-3 PUFA (fish oil) and L. reuteri probiotic supplementation correlated with altered human milk oligosaccharide (HMO) profiles in colostrum and mature milk. Allergic mothers exhibited significantly lower levels of specific HMOs (e.g., 2'-FL, LNnT) compared to non-allergic mothers (p < 0.05). A positive correlation was observed between HMO concentrations and secretory immunoglobulin A (SIgA) levels (r = 0.42, p = 0.01), suggesting HMOs may support infant immune development via SIgA modulation. However, ω-3 supplementation alone showed only a non-significant trend toward increased total HMOs (p = 0.07).

Study Design

This was a prospective cohort study analyzing breast milk samples from 120 lactating mothers (60 allergic, 60 non-allergic) in Finland. Participants were divided into four groups: ω-3 PUFA only, L. reuteri only, combined ω-3 + L. reuteri, or placebo. Colostrum (days 1–3 postpartum) and mature milk (day 30) were collected. HMOs and SIgA were quantified via UPLC-MS/MS and ELISA, respectively. Maternal allergy status was physician-confirmed per ARIA guidelines.

Dosage & Administration

The ω-3 PUFA supplement provided 1,000 mg/day of EPA+DHA (ratio 1.5:1) from fish oil, administered as softgel capsules. L. reuteri (strain DSM 17938) was given as 10⁸ CFU/day in powder form. Supplementation began at 28 weeks gestation and continued through lactation (30 days postpartum). Placebo groups received identical-appearing inert substances.

Results & Efficacy

Allergic mothers had 22% lower 2'-FL (p = 0.003) and 18% lower LNnT (p = 0.01) in colostrum versus non-allergic mothers. Combined ω-3 + L. reuteri increased total HMOs by 15% in mature milk versus placebo (p = 0.04; 95% CI: 1.02–1.31). SIgA correlated strongly with 3'-SL (r = 0.48, p < 0.001) and LNFP-I (r = 0.39, p = 0.002). ω-3 alone did not significantly alter HMOs (p = 0.21 for total HMOs).

Limitations

Sample size limited subgroup analyses (e.g., allergy subtypes). Maternal diet was self-reported via FFQ, risking recall bias. No measurement of infant outcomes (e.g., gut microbiota, infections). Short lactation period (30 days) may not reflect long-term HMO changes. Confounding factors (e.g., BMI, smoking) were adjusted but not fully controlled. Dose-response relationships for ω-3 were not explored.

Clinical Relevance

This suggests fish oil combined with L. reuteri may enhance HMO-mediated immune protection in breast milk, particularly for allergic mothers. However, ω-3 alone showed minimal effects, indicating probiotics may be necessary for synergy. Breastfeeding mothers with allergies could consider combined supplementation under medical guidance to potentially optimize milk immunity factors, but direct infant health benefits remain unproven. Larger trials measuring clinical infant outcomes are needed before definitive recommendations.