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Lactobacillus reuteri Improves Incretin and Insulin Secretion

Oct 16, 2015

Probiotic does not change insulin sensitivity in glucose-tolerant individuals.

Taking supplemental probiotics has been shown to influence the normal flora in the gut and perhaps can “alter intestinal permeability, and increase plasma GLP-1 concentrations and decrease postprandial glucose concentrations.” Simon and colleagues hypothesized that supplementation of Lactobacillus reuteri will improve insulin sensitivity and increases insulin secretion by promoting incretin release. They seek out to investigate the effect of L. reuteri on incretin, insulin sensitivity, and β-cell function. In addition, they also measure fat distribution as well as markers of systemic inflammation in healthy lean and obese individuals.


This was a double-blind, 1:1 randomized, prospective, longitudinal pilot trial for a duration of eight weeks. Both healthy lean and obese patients, without diabetes, participated in this study. Participants were given BIO-tract controlled release caplets with L. reuteri SD5865 at a dose of 2 x 1010 viable cells. The placebo group was given identical looking caplets. The studied group started with four weeks of placebo, then took the L. reuteri caplets twice a day for the next four consecutive weeks. All participants of the studied group treated with L. reuteri were tested positive after the intervention, while the participants in the placebo group remained negative (p < 0.0001).

There was a 76% increase seen for GLP-1 DAUC from baseline for those who were treated with L. reuteri. The increase in GLP-1 concentration explained the increased glucose-stimulated insulin secretion in the intervention group (49% increase in DAUC insulin). There was also an increase of DAUC C-peptide by 55%. Supplementation of L. reuteri did not change hepatic and peripheral insulin sensitivity, glucagon concentrations, body mass, ectopic fat content, or circulating cytokines.

Simon and colleagues demonstrated through this study that supplementation of L. reuteri probiotic increases insulin secretion, C-peptide, and GLP-1; however, insulin sensitivity as well as systemic inflammation or oxidative stress remained unchanged. Although the researchers were able to find that ingestion of L. reuteri helps to improve incretin and increase insulin secretion, the data cannot be readily applied to patients with type 2 diabetes because the participants in this study were all healthy lean and obese patients who do not have diabetes. Therefore, additional studies are warranted to see whether probiotic supplementations would help to improve incretin and increase insulin secretion in patients with type 2 diabetes.

Practice Pearls:

  • L. reuteri supplementations increases insulin secretion, C-peptide, and GLP-1.
  • L. reuteri supplementations does not change insulin sensitivity.
  • These information cannot be applied to patients with type 2 diabetes.

Simon MC, Strassburger K, Nowotny B, et al. Intake of Lactobacillus reuteri Improves Incretin and Insulin Secretion in Glucose-Tolerant Humans: A Proof of Concept. Diabetes Care 2015;38:1827-1834. Web. 27 Sep 2015.