Clinical application of probiotics in type 2 diabetes mellitus: A randomized, double-blind, placebo-controlled study

Abstract

Background & aims: Type 2 diabetes has been associated with dysbiosis and one of the possible routes to restore a healthy gut microbiota is by the regular ingestion of probiotics. We aimed to investigate the effects of probiotics on glycemic control, lipid profile, inflammation, oxidative stress and short chain fatty acids in T2D.

Methods: In a double-blind, randomized, placebo-controlled trial, 50 volunteers consumed daily 120 g/d of fermented milk for 6 wk. Participants were assigned into two groups: probiotic group, consuming fermented milk containing Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp lactis BB-12 (10⁹ colony-forming units/d, each) and control group, consuming conventional fermented milk. Anthropometric measurements, body composition, fasting blood and faecal samples were taken at baseline and after 6 wk.

Results: 45 subjects out of 50 (90%) completed follow-up. After 6 wk, there was a significant decrease in fructosamine levels (-9.91 mmol/L; p = 0.04) and hemoglobin A₁c tended to be lower (-0.67%; p=0.06) in probiotic group. TNF-α and resistin were significantly reduced in probiotic and control groups (-1.5 and -1.3 pg/mL, -.1 and -2.8 ng/mL, respectively), while IL-10 was significantly reduced (- 0.65 pg/mL; p <0.001) only in the control group. Fecal acetic acid was increased in both groups (0.58 and 0.59% in probiotic and control groups, respectively; p <0.01). There was a significant difference between groups concerning mean changes of HbA_1c (+0.31 for control group vs -0.65 for probiotic group; p=0.02), total cholesterol (+0.55 for control group vs -0.15 for probiotic group; p=0.04) and LDL-cholesterol (+0.36 for control group vs -0.20 for probiotic group p=0.03).

Conclusions: Probiotic consumption improved the glycemic control in T2D subjects, however, the intake of fermented milk seems to be involved with others metabolic changes, such as decrease in inflammatory cytokines (TNF-α and resistin) and increase in the acetic acid.

Keywords: Gut microbiota; Inflammation; Probiotics; SCFA; Stress oxidative; Type 2 diabetes.