Effect of caloric restriction with probiotic supplementation on body composition, quality of life, and psychobiological factors of obese men: A randomized, double-blinded placebo-controlled clinical trial

Background & aims

Obesity is a chronic disease characterized by an excess of fat mass. It is accompanied by a low-grade chronic systemic inflammation state that leads to numerous health disorders. To counteract this scenario, dietary-derived caloric restriction (CR) is the principal intervention for weight loss. Furthermore, probiotic supplementation has gained attention as a co-intervention to optimize weight loss and other health-related factors. As such, we aimed to verify the effect of CR with probiotic supplementation on the body composition, quality of life, sleep quality, anxiety, stress, and depression symptoms of adult men living with obesity.

Methods

The study is called the Clinical Study of Obesity and Intestinal Microbiota (ECOMI). It is a randomized, double-blind, placebo-controlled clinical trial involving two parallel groups of stable-weight adult men living with obesity. The inclusion criteria were male individuals aged 25–44 years, with body mass index (BMI) ranging from 30.0 to 39.99 kg/m², and stable body mass over the preceding three months. Participants were randomly assigned to two groups: Caloric Restriction with Probiotic (CRPRO) and Caloric Restriction with Placebo (CRPLA). The achieved CR was 30 % of the total daily energy expenditure. Macronutrients were distributed as 50 % carbohydrates, 30 % lipids, and 20 % proteins. Probiotic supplementation was carried out using two sachets/day of 1 g, containing 1 × 10⁹ Colony Forming Units (CFU) of each strain: Lactobacillus acidophilus NCFM, Lactobacillus rhamnosus HN001, Lactobacillus paracasei Lpc-37 and Bifidobacterium lactis HN019, totaling 8 billion CFU/day. CR and probiotic (or placebo) supplementation intervention lasted 12 weeks. Body composition and psychobiological-related parameters (e.g., sleep, anxiety, stress, and depression) were assessed at baseline and following 12 weeks of intervention. Data are presented as mean and 95 % confidence interval (CI) and mean difference (MD).

Results

The present study applied the per protocol analysis. Thirty-three subjects were evaluated and randomized, but only data from 25 (CRPLA n = 12 vs CRPRO n = 13) participants were included in the final analysis. We verified that CR resulted in weight loss (p < 0.001; η²ρ = 0.754) in both CRPLA (MD: −6.30 kg; p < 0.001) and CRPRO (MD: −5.97 kg; p < 0.001), without differences between groups (p = 0.823; η²ρ = 0.002). Moreover, both CRPLA (MD: −4.83 kg; p < 0.001) and CRPRO (MD: −5.20 kg; p < 0.001) decreased body fat without difference between groups (p = 0.712; η²ρ = 0.006). Regarding obesity-related problems, only the corporeality dimension (p < 0.001; η²ρ = 0.474) in both CRPLA (p = 0.028) and CRPRO (p = 0.039) improved. World Health Organization Quality of Life (WHOQoL)-related dimensions were improved for perception (p < 0.001; η²ρ = 0.630), satisfaction (p < 0.001; η²ρ = 0.778), and psychological domain (p < 0.001; η²ρ = 0.567), without differences between groups. Moreover, sleep quality (p < 0.001; η²ρ = 0.522) improved in both groups, without differences between groups. Finally, anxiety (p = 0.013; η²ρ = 0.250) and depression (p = 0.003; η²ρ = 0.345) scores assessed via the Depression, Anxiety and Stress Scale-21 (DASS-21) and the Beck Depression Inventory (BDI-II) (p < 0.001; η²ρ = 0.448) improved only in the CRPRO group.

Conclusions

Probiotic supplementation did not enhance the effects of caloric restriction on body composition, QoL-, or sleep-related parameters. However, anxiety and depressive symptoms improved only in the CRPRO group, despite no differences between groups after 12 weeks. Further studies are needed to confirm these findings.