Effects of Lactobacillus curvatus HY7601 and Lactobacillus plantarum KY1032 on Overweight and the Gut Microbiota in Humans: Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

Abstract

Obesity and overweight are closely related to diet, and the gut microbiota play an important role in body weight and human health. The aim of this study was to explore how Lactobacillus curvatus HY7601 and Lactobacillus plantarum KY1032 supplementation alleviate obesity by modulating the human gut microbiome. A randomized, double-blind, placebo-controlled study was conducted on 72 individuals with overweight. Over a 12-week period, probiotic groups consumed 1 × 1010 colony-forming units of HY7601 and KY1032, whereas the placebo group consumed the same product without probiotics. After treatment, the probiotic group displayed a reduction in body weight (p < 0.001), visceral fat mass (p < 0.025), and waist circumference (p < 0.007), and an increase in adiponectin (p < 0.046), compared with the placebo group. Additionally, HY7601 and KY1032 supplementation modulated bacterial gut microbiota characteristics and beta diversity by increasing Bifidobacteriaceae and Akkermansiaceae and decreasing Prevotellaceae and Selenomonadaceae. In summary, HY7601 and KY1032 probiotics exert anti-obesity effects by regulating the gut microbiota; hence, they have therapeutic potential for preventing or alleviating obesity and living with overweight.

Keywords: Lactobacillus curvatus HY7601; Lactobacillus plantarum KY1032; body weight; gut microbiota; obesity; overweight; probiotics.

Figure 1

Flow chart illustrating the steps for screening, enrollment, assignment, and follow-up of study participants for per protocol (PP) analysis.

Figure 2

Results of anthropometric variable measurements. The graphs show (A) body weight, (B) BMI, (C) waist circumference, (D) body fat mass, (E) lean mass, and (F) visceral fat area, which all decreased in the probiotics group after 12 weeks of intervention. The data points correspond to the mean ± SEM. p-value are derived from ANCOVA tests adjusted for baseline values. DF, difference of least square mean from placebo group; LS mean, least square mean.

Figure 3

Adipokines measured via ELISA at baseline and at 12-weeks’ follow-up and mean changes according to treatment. (A) Leptin, (B) adiponectin. The data points correspond to the mean ± SEM. p-value are derived from ANCOVA tests adjusted for baseline values. DF, difference of least square mean from placebo group; LS mean, least square mean.

Figure 4

Bacterial family abundance, alpha diversity, and beta diversity. (A) Relative abundance at the family level at baseline and after intervention in placebo and probiotic groups. Boxplots show the alpha diversity of bacterial communities at baseline and after intervention in placebo and probiotics groups for (B) observations and (C) ACE, (D) Shannon, and (E) Chao1 indices. (F) Principal coordinate analysis (PCoA) showing the microbial community distance between baseline in the placebo group (orange circles), after intervention in the placebo group (green circles), baseline in the probiotic group (blue circles), and after intervention in the probiotic group (purple circles). Each group is identified by a different color, as shown to the right of the figure. BPLA, before placebo; APLA, after placebo; BPRO, before probiotics; APRO, after probiotics.

Figure 5

Linear discriminant analysis (LDA) effect size (LEfSe) cladogram and plots of microbial taxa between baseline and after intervention for placebo (A) and probiotics (B) group. The LEfSe algorithm was applied using the Galaxy computational tool v.1.0. (https://huttenhower.sph.harvard.edu/galaxy/, accessed on 15 April 2022). The diameter of each circle is proportional to the abundance of the taxon. The length of the bar represents the log10 transformed LDA score. The threshold on the logarithmic LDA score for discriminative features was set to 3.0. Only taxa of bacteria with statistically significant changes (p < 0.05) in relative abundance is written on the horizontal line. The name of the taxon level is abbreviated as p—phylum; c—class; o—order; f—family, and g—genus. BPLA, before placebo; APLA, after placebo; BPRO, before probiotics; APRO, after probiotics.

Figure 6

Relative abundance changes of six fecal microbiota species at baseline and after intervention in each group. (A) Bifidobacterium adolescentis. (B) Bifidobacterium longum. (C) Akkermansia muciniphila. (D) Faecalibacterium prausnitzii. (E) Prevotella copri. (F) Collinsella aerofaciens. Species are shown in the boxplot. The p-values were obtained by performing Mann–Whitney U-tests for differences between groups at baseline or after intervention.

Figure 7

Pearson correlation analysis. Pearson’s correlation analysis was performed between the bacterial species-level taxa and the measured anthropometric values. Heatmaps were generated in MORPHEUS software (https://software.broadinstitute.org/morpheus/, accessed on 15 April 2022). In heatmaps, red squares indicate significant positive correlations (r > 0.3) and blue squares indicate significant negative correlations (r < − 0.3). (* p < 0.05). WC, waist circumference; FM, fat mass; VFA, visceral fat area.