The review specifically looked at the benefits of probiotics supplementation in women with gestational diabetes, PCOS, and infant allergy management.
All randomised controlled trials studying the effects of probiotics in pregnant women or women of reproductive age (between 15 and 49 years old) were studied in the review.
A range of probiotics were used in the trials, including supplements or fortified foods and beverages.
The review was conducted by the Nestle Research teams in Singapore, China, and Switzerland. Findings were published on Frontiers in Nutrition.
While the researchers acknowledged that they could not strongly conclude the benefits of probiotics supplements, specific probiotic strains and mixture could still be beneficial.
“We cannot strongly conclude on the impact of probiotic interventions on markers of inflammation and health outcomes in women of reproductive age and their children, due to the heterogeneity of the study results,” the researchers said.
However, they added that “specific probiotic strain or specific probiotic mix administration may provide beneficial effects in premenopausal women.”
This can be seen in the case for modulating inflammation.
“Results in health and disease for the modulation of inflammatory markers are still highly conflicting.
“Modulation of TNF-α and IL-6 or the regulatory cytokine IL-10 may depend on the specificity of the probiotics, the health or disease state and the timing of the intervention.”
Case study: PCOS and gestational diabetes
Gestational diabetes and PCOS are two examples of conditions caused by chronic low-grade inflammation, and specific probiotics strains have shown to control inflammatory markers.
The researchers cited a study conducted in Iran and published in 2018, where 60 women with PCOS were randomised to take probiotics for 12 weeks.
Four probiotic strains, L. acidophilus, L. plantarum, L. fermentum, and L. gasseri at 2 × 109 CFU of each strain were given to the probiotic group each day.
Results showed that serum levels of the anti-inflammatory cytokine IL-10 had significantly increased in the group with probiotic supplementation as compared to the placebo group.
Serum level of pro-inflammatory cytokine IL-6 showed a significant decrease in both groups.
However, serum level of pro-inflammatory cytokine TNF-α showed no significant differences between the two groups.
“These four lactobacilli probiotic strains can be useful in modulating inflammation markers and help with metabolic dysfunctions, but other studies need to confirm these findings,” said the researchers.
As for gestational diabetes, a study published in 2018 showed that probiotic supplementation had reduced the serum level of certain pro-inflammatory cytokines such as TNF-α, but not all of them.
In the RCT, the intervention group took probiotics containing L. acidophilus La5, B. lactis Bb12, S. thermophilus STY-31, and L. delbrueckii bulgaricus LBY-27 for eight weeks during pregnancy.
The intervention group showed a significantly lower serum TNF-α as compared to the placebo.
However, there were no significant differences between the 2 groups in serum IL-6 levels.
“Probiotics as a unique approach may not be a meaningful strategy in the prevention of GDM but could be considered as part of more holistic approaches to improve glycemic response and glucose metabolism in women.
“We hypothesize that probiotics may be useful to reduce the risk of GDM when used in conjunction with other strategies such as dietary interventions, obesity management or when used in combination with other bioactives,” the researchers said.
Case study: Infant allergy risk reduction
The importance of probiotics strains specificity in reducing conditions caused by inflammation was also seen for infant allergy risk reduction.
Citing a study in New Zealand, it was found that while two different strains of probiotics could similarly affect the inflammatory markers in breast milk, they showed different effects in eczema risk reduction in toddlers.
In the study, L. rhamnosus HN001 at 6 × 109 CFU/day or B. animalis subsp lactis HN019 at 9 × 109 CFU/day were given to pregnant women from their 35th week of gestation up to 6 months postpartum and subsequently, up to 2 years in the infants via formula or solid food.
Results showed that probiotic administration had significantly increased the levels of TGF-β1 in breast milk as compared to the placebo group.
Effects of this were more pronounced in the B. lactis HN019 group than the L. rhamnosus HN001 group.
Interestingly, it was the L. rhamnosus group supplementation group that showed a significantly reduced risk of eczema at 2 years (HR 0.51; 95% CI, 0.30–0.85) compared to the placebo.
The reduced risk of eczema was however, not observed in the B. lactis group.
“It may suggest there may be a multitude of other factors linked to L. rhamnosus immunoregulation of infant allergy that B. lactis HN019 does not have and confirm that infant atopic dermatitis risk reduction is not solely reliant on breast milk cytokine profiles,” the researchers concluded.
Source: Frontiers in Nutrition
Effects of Probiotic Intervention on Markers of Inflammation and Health Outcomes in Women of Reproductive Age and Their Children
Authors: Kwok et al