Low-grade inflammation linked to persistent post-partum obesity and glucose intolerance (GI) in women who have recently experienced gestational diabetes mellitus (post-GDM) is a major public health concern. While probiotics are often used as an adjuvant therapy in several diseases, there has been little data on how they impact the gut microbiota composition and metabolic and inflammatory outcomes in women with a recent history of post-GDM.
As such, researchers from three Malaysian universities — Universiti Kebangsaan Malaysia, Universiti Pertahanan Nasional Malaysia and Universiti Malaysia Pahang — conducted a randomized, double-blind, placebo-controlled clinical trial involving 132 asymptomatic post-GDM women aged 18 to 45. The post-GDM women recruited for the study either had post-partum GI and were asymptomatic of hyperglycaemia, or were overweight or obese but had normal glucose tolerance.
Over the course of the 12-week study, the intervention group received a mixture of six probiotic strains from Bifidobacterium and Lactobacillus, while the placebo group received an identical sachet containing no probiotics or other live microorganisms. The researchers evaluated the study subjects’ anthropometric measurements, biochemical analyses, and 16S rRNA gene sequencing results before and after the intervention.
The pros of probiotics
Following the 12-week intervention, the researchers observed that the women in the group who had received probiotics showed “significantly decreased” fasting blood glucose (FBG) levels. Between the intervention and placebo groups, levels of glycated haemoglobin, total cholesterol, triglycerides and high-sensitivity C-reactive protein were markedly different, with the former showing improved results after probiotics supplementation.
Additionally, sequencing data demonstrated a large rise in the Bifidobacterium adolescentis after probiotic supplementation. The researchers wrote that these results suggested that multi-strain probiotics were “beneficial for improved metabolic and inflammatory outcomes in post-GDM women by modulating gut dysbiosis”. The women in the intervention group also saw decreased waist circumference, as well as restored metabolic pathways and gut microbial profiles and functions.
The researchers further noted that beneficial gut microbiota such as Lachnospiraceace, Dubosiealla, Bifidobacterium, Lactobacillus, Olsenella, Allobaculum and Clostridium sensu stricto were typically elevated following probiotic supplementation. This could, in turn, positively impact metabolism by regulating the production of short-chain fatty acids (SCFAs).
Modest and moderate effects
While the study found significant differences in specific outcomes between the intervention and placebo groups, it also noted that in terms of FBG levels, the effect size was “at the low end of moderate”. Furthermore, 31.7% of the women in the intervention group showed no improvement. However, this may have been due to baseline FBG levels in asymptomatic post-GDM women being within the normal range, or other unobserved factors.
Probiotic supplementation also reduced glycated haemoglobin levels in the intervention group only marginally (by 0.02%), possibly due to probiotics being less efficient in overweight or obese people. Besides this, participants had to maintain their regular diets and as such, consumed little dietary fibre — an important source of prebiotics that encourage gut microbiota modulation.
Still, the researchers said that even a small reduction in glycaemic profile could help to hinder the progression of type 2 diabetes mellitus (T2DM) in post-GDM women.
Considering the minimal beneficial effects of probiotics on metabolic outcomes, their activities in the study were deduced as “geared more toward reducing illness severity than treating it”.
The researchers concluded that the pros and cons of probiotics in post-GDM women needed to be carefully understood and customized as they could differ among individuals, depending on lifestyle and pre-existing gut bacteria makeup.
They added that study emphasized the need for a “comprehensive strategy for post-partum treatment that includes probiotics” to prevent GI in post-GDM women. Morever, both a healthy lifestyle and probiotics supplementation should be implemented as “a viable preventive therapy in order to remodel gut dysbiosis and metabolic outcomes in post-GDM women”.
“The Roles of Probiotics in the Gut Microbiota Composition and Metabolic Outcomes in Asymptomatic Post-Gestational Diabetes Women: A Randomized Controlled Trial”
Authors: Zubaidah Hasain, et al.