Background: The present randomized clinical trial characterized the beneficial effects of a multi-strain probiotics supplementation on improving circulating endotoxin levels (primary endpoint) and other cardiometabolic biomarkers (secondary endpoint) in patients with T2DM. 
Methods: A total of 78 adult Saudi T2DM patients (naïve and without co-morbidities) participated in this clinical trial and were randomized to receive twice daily placebo or probiotics [(2.5×109 cfu/gram) containing the following bacterial strains: Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, Lactobacillus casei W56, Lactobacillus salivarius W24, Lactococcus lactis W19 and Lactococcus lactis W58 (Ecologic®Barrier)]  in a double-blind manner for 12 weeks. Anthropometrics and cardiometabolic profiles were obtained at baseline and after 12/13 weeks of treatment. 
Results: After 12/13 weeks of intervention and using intention-to-treat analysis, no difference was noted in endotoxin levels between groups [Placebo -9.5% vs Probiotics -52.2%; (CI: -0.05-0.36; p=0.15)]. Compared with the placebo group however, participants in the probiotics groups had a significant but modest improvement in WHR [Placebo 0.0% vs Probiotics 1.11%; (CI: -0.12- -0.01; p=0.02)] as well as a clinically significant improvement in HOMA-IR [Placebo -12.2% vs Probiotics -60.4%; (CI: -0.34- -0.01; p=0.04)]. 

Discussion: A recent meta-analysis of RCTs done thus far on probiotics and T2DM revealed that multiple species of probiotics and interventions longer than 8 weeks had stronger metabolic improvements in terms of improved glucose control and lipid profiles [1]. With 8-strains of probiotics supplements used over 3 month duration, we confirm these beneficial effects in reducing abdominal adiposity (measured as WHR) and insulin resistance (HOMA-IR). The lack of improvement in lipid profile however and other indices assessed in the present study do not supersede previous findings. Our results are in agreement with a recent double-blind, randomized trial involving 43 participants (Placebo N=22 and Probiotic mix N=21) who were given 8 weeks supplementation of probiotic mix (Lactobacillus acidophilus and casei; Lactococcus lactis; Bifidobacterium bifidum and lactis; 2×1010 colony-forming units/day) and found significant reduction in abdominal adiposity with no concomitant decrease in endotoxin levels [2].
Conclusion: In summary, a 12-week, multi-strain probiotic supplementation in medication naïve T2DM individuals resulted in no significant changes in circulating endotoxin levels but has been beneficial in terms of improved HOMA-IR and modest reduction in abdominal adiposity. A larger cohort and a longer duration of treatment may be necessary to investigate if probiotic supplementation can be protective against diabetic complications.
Trial Registration: ClinicalTrials.gov Identifier: NCT01765517, Registered January 10, 2013; https://clinicaltrials.gov/ct2/show/NCT01765517

Funding
This project is funded by the National Plan for Science and Technology (NPST) (Grant Number: 11-MED2114-02).

Daily intake of a 7-strain probiotic supplement for 12 weeks improves cardiometabolic profiles of naïve T2DM patients