A randomised controlled study shows supplementation of overweight and obese adults with lactobacilli and bifidobacteria reduces bodyweight and improves well-being

Abstract

In an exploratory, block-randomised, parallel, double-blind, single-centre, placebo-controlled superiority study (ISRCTN12562026, funded by Cultech Ltd), 220 Bulgarian participants (30 to 65 years old) with BMI 25-34.9 kg/m² received Lab4P probiotic (50 billion/day) or a matched placebo for 6 months. Participants maintained their normal diet and lifestyle. Primary outcomes were changes in body weight, BMI, waist circumference (WC), waist-to-height ratio (WtHR), blood pressure and plasma lipids. Secondary outcomes were changes in plasma C-reactive protein (CRP), the diversity of the faecal microbiota, quality of life (QoL) assessments and the incidence of upper respiratory tract infection (URTI). Significant between group decreases in body weight (1.3 kg, p < 0.0001), BMI (0.045 kg/m², p < 0.0001), WC (0.94 cm, p < 0.0001) and WtHR (0.006, p < 0.0001) were in favour of the probiotic. Stratification identified greater body weight reductions in overweight subjects (1.88%, p < 0.0001) and in females (1.62%, p = 0.0005). Greatest weight losses were among probiotic hypercholesterolaemic participants (-2.5%, p < 0.0001) alongside a significant between group reduction in small dense LDL-cholesterol (0.2 mmol/L, p = 0.0241). Improvements in QoL and the incidence rate ratio of URTI (0.60, p < 0.0001) were recorded for the probiotic group. No adverse events were recorded. Six months supplementation with Lab4P probiotic resulted in significant weight reduction and improved small dense low-density lipoprotein-cholesterol (sdLDL-C) profiles, QoL and URTI incidence outcomes in overweight/obese individuals.

Figure 1

(a) Scheme of sample/data collection and (b) Flow diagram of the study. QoLQ, quality of life questionnaire; URTI, upper respiratory tract infection.

Figure 2

Changes from baseline in (a) body weight, (b) BMI, (c) WC, (d) WtHR, (e) SBP and (f) DBP over the duration of the intervention period. Data is presented as mean change from baseline (110 participants per group) with 95% CIs and p values were calculated using a LMM. For within group comparisons (vs baseline): **p ≤ 0.01 and ***p ≤ 0.001. For between group comparisons (active vs placebo): ^###p ≤ 0.001. BMI, body mass index; WC, waist circumference; WtHR, waist-to-height ratio; SBP, systolic blood pressure; DBP, diastolic blood pressure.

Figure 3

Forest plot of between group changes in body weight in the stratified subgroups at 6 months. Data is presented as mean change with 95% CIs and p values calculated using a LMM. n, number of participants (active/placebo); TC, total cholesterol; CI, confidence interval.

Figure 4

Forest plot of between group changes in plasma biochemistry in SG3c (TC ≥ 6.2 mmol/L) at 6 months. Data is presented as mean change with 95% CIs and p values were calculated using a GLM. n, number of participants (active/placebo); TC, total cholesterol; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; sdLDL-C, small dense LDL-C, TG, triglycerides; CI, confidence interval.

Figure 5

Diversity within the faecal microbiota of the active and placebo groups over the duration of the study. (a) Box-and-whisker plot showing the Chao1 and Shannon diversity (alpha-diversity) and (b) a non-metric dimensional scaling (NMDS) plot showing the weighted unifrac (beta-diversity) of the active group and placebo group at baseline and 6 months were generated and differences were assessed with PERMANOVA; statistical outliers are represented as black dots and no significant changes were observed. Ellipses represent the 95% confidence interval. The data represents 80 samples at baseline (43 active and 37 placebo) and 64 samples at 6 months (35 active and 29 placebo) from which a total of 3,522,472 reads (mean reads per sample = 24,461 ± 7,399) were retained after quality filtering and 7,075 unique OTUs were identified and quantified (0.1 non-zero values fraction). 11,001 reads per sample were obtained after rarefaction to the smallest library size. Filtering of the low-abundant OTUs retained 2,047 OTUs that were grouped into 11 phyla and 205 genera.