Effect of different doses of Lacticaseibacillus paracasei K56 on body fat and metabolic parameters in adult individuals with obesity: a pilot study

BACKGROUND: Studies have shown that probiotics have an effect on reducing body fat on a strain-specific and dose–response bases. The purpose of this study was to evaluate the effect of a novel probiotic strain Lacticaseibacillus paracasei K56 on body fat and metabolic biomarkers in adult individuals with obesity. METHODS: 74 adult subjects with obesity (body mass index ≥ 30 kg/m(2), or percent body fat > 25% for men, percent body fat > 30% for women) were randomized into 5 groups and supplemented with different doses of K56 (groups VL_K56, L_K56, H_K56, and VH_K56: K56 capsules, 2 × 10(7) CFU/day, 2 × 10(9) CFU/day, 2 × 10(10) CFU/day, 2 × 10(11) CFU/day, respectively) or placebo (group Pla: placebo capsule) for 60 days. Subjects were advised to maintain their original dietary intake and physical activity. Anthropometric measurements, body composition assessment, and metabolic parameters were measured at baseline and after 60 days of intervention. RESULTS: The results showed that the L_K56 group had significant decreases in percent body fat (p = 0.004), visceral fat area (p = 0.0007), total body fat mass (p = 0.018), trunk body fat mass (p = 0.003), waist circumference (p = 0.003), glycosylated hemoglobin(p = 0.002) at the end of the study compared with baseline. There were non-significant reductions in Body weight and BMI in the L_K56, H_K56, VL_K56 groups, whereas increases were observed in the placebo and VH_K56 groups compared with baseline values. In addition, K56 supplementation modulated gut microbiota characteristics and diversity indices in the L-K56 group. However, mean changes in body fat mass, visceral fat area, weight, body mass index, waist circumference and hip circumference were not significantly different between groups. CONCLUSIONS: The results suggest that supplementation with different doses of Lacticaseibacillus paracasei K56 has certain effect on reducing body fat and glycosylated hemoglobin, especially at a dose of 10(9) CFU/day. Trial registration: clinicaltrials.gov Identifier: NCT04980599.