The Korean team were able to demonstrate that an eight-week course of Lactobacillus plantarum HAC01 improved indicators of Type 2 Diabetes (T2D) onset, when compared to the control group.
Writing in the Nutrients journal, the team notes, “L. plantarum HAC01 supplementation significantly improved HbA1c and 2h-PPG levels relative to placebo in prediabetic subjects,”
“No serious adverse effects were observed, suggesting that L. plantarum HAC01 has potential as an effective lifestyle intervention to forestall or prevent the onset of T2D,” the team adds.
The team from Chonbuk National University Hospital began enrolling forty subjects with impaired glucose tolerance and randomly assigned them to receive either a daily placebo (sample size = 20) or a dose of Lactobacillus plantarum HAC01 (sample size = 20) over eight weeks.
The primary endpoint was a change in 2-hour postprandial glucose (2h-PPG) levels. Secondary endpoints were assessment of HbA1c levels, gut microbiota composition, and faecal short-chain fatty acids (SCFAs).
The group with a diet supplemented with L. plantarum HAC01 saw a significant reduction in 2h-PPG and HbA1c levels compared to the placebo group.
Fasting plasma glucose, insulin, HOMA-IR, QUICKI, microbiota composition, and faecal SCFAs, however, were not significantly altered. No serious adverse effects were reported.
“In contrast with the results of our animal study, in which L. plantarum HAC01 increased the presence of the Akkermansiaceae family and decreased the presence of the Desulovibrionaceae family in mice faeces, we observed no changes in the abundance or taxonomic composition of the human faecal microbiome.
“These results suggest that it is microbial products, and not a difference in microbiota composition, that perform a regulatory role in glycaemic control in humans.”
Recent studies have established that changes to the gut microbiota make-up contribute to the onset of insulin resistance in humans.
A reduced presence of Firmicutes and relatively higher levels of Bacteroidetes are found in type 2 diabetic patients, as compared to healthy individuals.
Bifidobacterium and Lactobacillus species are the gut microbiota most commonly found in probiotics, and their ability to improve glucose homeostasis has been reported in several clinical trials.
One such study noted the administration of L. plantarum HAC01 also improved glycaemic control by restoring gut microbiota composition in diabetic mice.
Here, T2D was induced by a high-fat diet after the onset of pancreatic dysfunction. Reports like this suggests this strain may have the potential to treat T2D in humans.
SCFA’s as a microbial-derived product was a central focus for the team’s discussion, in which recent studies have implicated acetate, propionate, and butyrate as metabolites that link gut microbiota with their health-promoting qualities.
SCFA binds to the receptors of free fatty acids, such as GPR41 and GPR43, and increases insulin sensitivity and pancreatic β-cell proliferation, according to one recent study.
“A comparison of baseline and Week 8 values confirmed no changes in the plasma concentrations of various SCFAs in subjects who received L. plantarum HAC01, suggesting that circulating SCFAs derived from gut microbiota were likely not responsible for the observed improvements in HbA1c levels,” the team writes.
However, the study thought this to be an area of further exploration, with SCFAs proposed as the most probable mechanism by which probiotics promote health outcomes.
The team cites a number of studies that indicate faecal levels of SCFAs are affected by factors as diverse as microbiota composition, colonic transit time, luminal pH, host health status, and colonic clearance.
“The number of subjects in each group we sampled was small,” the team highlights. “Accordingly, our results should be treated as preliminary.
“Larger scale studies will validate these issues and assess the exact mechanism(s) by which L. plantarum HAC01 influences glucose parameters.”
Published online: doi.org/10.3390/nu13072337
“Lactobacillus plantarum HAC01 Supplementation Improves Glycemic Control in Prediabetic Subjects: A Randomized, Double-Blind, Placebo-Controlled Trial.”
Authors: Mi-Ra Oh et al.