Objectives: The connections between gut microbiota, energy homeostasis, and inflammation and its role in the pathogenesis of obesity-related disorders are increasingly recognized. We aimed to investigate the effect of the probiotic strain Lactobacillus salivarius Ls-33 on a series of biomarkers related to inflammation and the metabolic syndrome (MS) in adolescents with obesity.
Methods: The study was a double-blind placebo-controlled trial including 50 adolescents with obesity randomized to Ls-33 (1010 CFU) or placebo daily for 12 weeks.
Results: The average body mass index-for-age z-score was 2.6 ± 0.5. There were no differences in biomarkers of inflammation and parameters related to the MS at baseline between the probiotic and placebo groups. Furthermore, there were no differences in changes from baseline to 12-week intervention with regard to any anthropometric measures, blood pressure (systolic and diastolic), fasting glucose and insulin, homeostasis model assessment of insulin resistance, C-peptide, cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, free fatty acids, C-reactive protein, interleukin-6, tumor necrosis factor alpha, or fecal calprotectin, despite the increased values of biomarkers of inflammation and of several parameters related to the MS at baseline when compared with normal-weight adolescents. The levels of L salivarius in fecal samples from the probiotic group in the present study were comparable with the levels reported for the other probiotic lactobacilli and bifidobacteria using quantitative polymerase chain reaction.
Conclusions: It was not possible to detect any beneficial effect of the probiotic intervention with Ls-33 on inflammatory markers or parameters related to the MS in adolescents with obesity being in a state of low-grade systemic inflammation.