Effects of Probiotic Yogurt on Fat Distribution and Gene Expression of Proinflammatory Factors in Peripheral Blood Mononuclear Cells in Overweight and Obese People with or without Weight-Loss Diet

Abstract

Objectives: The purpose of this study was to investigate whether probiotics had an effect on proinflammatory markers and cytokines in overweight and obese individuals and whether they could have synergistic effects with weight-loss diets.

Methods: A total of 75 healthy overweight and obese individuals completed this randomized doubled-blind controlled clinical trial. Participants were randomly assigned to groups consuming regular yogurt with a low-calorie diet (LCD, RLCD; n = 25) or receiving probiotic yogurt with LCD (PLCD; n = 25) or consuming probiotic yogurt without LCD (PWLCD; n = 25) for 8 weeks. The pribiotic regimen contained 200 g/day yogurt, enriched by Lactobacillus acidophilus La5, Bifidobacterium BB12, and Lactobacillus casei DN001 10⁸ colony-forming units/g. Body fat percentage, high-sensitive C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), leptin, and mRNA levels of inflammation-related genes (TNF-α and RAR-related orphan receptor gamma [ROR-γt]) in peripheral blood mononuclear cells (PBMCs) were measured.

Results: A reduction in body mass index (BMI), fat percentage, and leptin level was observed that was more obvious in groups who received the weight-loss diet with probiotic yogurt. Reduction in the gene expression of ROR-γt was significant in the PLCD group (p < 0.001). The expression of TNF-α did not change among all groups after intervention. The mean concentration of leptin was significantly decreased in all groups after the dietary intervention, but the mean changes in leptin level in the PLCD group was more prominent compared to the other two groups (−2.38, p < 0.001 [PLCD] vs −1.75, p = 0.002 [RLCD] and −0.55 ng/mL, p = 0.12 [PWLCD]). The reduction in serum levels of hs-CRP was more evident in the PWLCD group compared to the PLCD and RLCD groups after the 8-week intervention (−3.4, p = 0.03 vs −1.76, p < 0.001 and −2.98 pg/mL, p < 0.001, respectively).

Conclusion: Our results suggested that the weight-loss diet and probiotic yogurt had synergistic effects on T-cells subset specific gene expression in PBMCs, fat percentage, and body weight among overweight and obese individuals.

Key words::

• obesity
• hs-CRP
• probiotics
• leptin
• PBMCs

ACKNOWLEDGMENT

We thank the participants in the study for their important contributions and the Iran Dairy Industry Corporation (IDIC-Pegah) for preparation of the probiotic yogurt.