The efficacy of probiotics for monosodium glutamate-induced obesity: dietology concerns and opportunities for prevention

Abstract

Introduction: Obesity becomes endemic today. Monosodium glutamate was proved as obesogenic food additive. Probiotics are discussed to impact on obesity development.

Aims and objectives: The aim was to study the effects of probiotics on the development of monosodium glutamate (MSG)-induced obesity in rats.

Material and methods: We included 45 Wistar male rats and divided into three groups (n = 15). Newborn rats of group 1 (control) received subcutaneously 8 μl/g saline. Group 2 received 3 to 4 mg/g MSG subcutaneously on the second, fourth, sixth, eighth and tenth day of life. Within 4 months after birth, rats were on a standard diet. Group 3 received an aqueous solution of probiotics mixture (2:1:1 Lactobacillus casei IMVB-7280, Bifidobacterium animalis VKL, B. animalis VKB) at the dose of 5 × 109 CFU/kg (50 mg/kg) intragastrically. Administration of probiotics was started at the age of 4 weeks just after weaning and continued for 3 months during 2-week courses. Group 2 received intragastrically 2.5 ml/kg water. Organometric and biochemical parameters in all groups of rats were analyzed over 4 months. The concentration of adiponectin was determined in serum, and leptin - in adipose tissue.

Results: Administration of MSG led to the development of obesity in rats; body weight had increased by 7.9% vs controls (p < 0.05); body length had increased by 5.4% (p < 0.05). Body mass index and Lee index and visceral fat mass had increased (p < 0.001). Under the neonatal injection of MSG, the concentration of total cholesterol, triglycerides, VLDL cholesterol and LDL cholesterol significantly increased (p < 0.001), in comparison with controls. Adipose-derived hormones changed in MSG obesity rats: adiponectin decreased by 58.8% (p < 0.01), and leptin concentration in adipose tissue had increased by 74.7% (p < 0.01). The probiotic therapy of rats from group 3 prevented obesity development. Parameters of rats treated with probiotic mixture did not differ from that in the control.

Conclusions: The introduction of MSG to newborn rats caused the obesity in adulthood. Periodic administration of probiotic mixture to rat injected with MSG neonatally resulted in recovery of lipid metabolism and prevention of the obesity development.

Figure 1

Concentration of adipose-derived hormones. (A) Concentration of adiponectin in serum (mkg/ml) and (B) concentration of leptin in adipose tissue of rats with glutamate-induced obesity and corrected by probiotics; double asterisks (**), p < 0.01 in comparison with group 1; double number signs (##), p < 0.01 in comparison with group 2.