Bacteroides vulgatus alleviates heart failure via butyric acid-TGF-β1/MAPK pathway

Figures

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  Fig. 1. Alterations in heart failure (HF) patients’ gut microbiome. (A) The gut microbiota’s α-diversity as measured by the Chao1 and Shannon indices [n = 30 (Healthy controls) to 60 (HF patients), Wilcoxon test]. (B) Principal coordinate analysis (PCoA) plot of the β-diversity index. (C) The barplot of the gut microbiota structure at the phylum level. (D) The barplot of the gut microbiota structure at the genus level. (E, F) The microbial differences on the genus (E) and species (F) levels (n = 30 to 60, Kruskal-Wallis H test). (G) LEfSe investigation of the structure of the gut microbiota. (H) The relative abundance of B. vulgatus [n = 30 (Healthy controls) to 60 (HF patients), Student’s t test]. Data are shown as mean ± SD. **p < 0.01 vs. healthy controls group.

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  Fig. 2. Dysbiosis of the gut microbiota can lead to cardiac dysfunction in mice. (A) Experimental study overview. (B) The levels of BNP and NT-proBNP in the FC-FMT and FHF-FMT groups (n = 5, Student’s t test). (C) Echocardiographic results of the FC-FMT and FHF-FMT groups (n = 5, Student’s t test). (D, E) H&E, Masson and WGA staining of the myocardial tissue in the FC-FMT and FHF-FMT groups (D) and quantitative results (E). (F) Small intestine H&E staining in the control, FC-FMT and FHF-FMT groups. Data are shown as mean ± SD. **p < 0.01, vs. control group. ##p < 0.01, vs. FC-FMT group. FC-FMT: the mice treated with fecal microbiota from control mice; FHF-FMT: the mice treated with fecal microbiota from HF mice.

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  Fig. 3. Effects of B. vulgatus on heart failure (HF) in mice. (A) Echocardiographic results of each group of mice (n = 5, one-way ANOVA). (B) HF biomarkers levels in each group (n = 5, one-way ANOVA). (C-F) H&E, Masson, WGA, TUNEL-DAPI and α-actinin triple staining of each group's cardiac tissue (C) and quantitative results (D-F). (G) H&E staining of the small intestine. BV group: B. vulgatus-treated mice; ina-BV group: B. vulgatus treatment-treated mice. Data are shown as mean ± SD. ##p < 0.01 vs. control group, *p < 0.05, **p < 0.01 vs. model group.

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  Fig. 4. Changes in short-chain fatty acid (SCFA) profiles in heart failure (HF) patients and mice. (A) SCFAs levels in the serum of healthy controls and HF patients [n = 30 (Healthy controls) to 60 (HF patients), Wilcoxon test]. (B) SCFAs levels in the plasma of each group of mice (n = 5, Student’s t test). (C) SCFAs levels in the feces of each group of mice (n = 5, Student’s t test). (D) Echocardiographic results of each group of mice (n = 5, one-way ANOVA). (E) HF biomarker levels in each group (n = 5, one-way ANOVA). (F) Correlation investigation between the amount of SCFAs and the gut microbiota (n = 30 to 60, Wilcoxon test). (G, H) H&E, Masson, WGA and DAPI double staining of each group’s cardiac tissue (G) and quantitative results (H). Data are shown as mean ± SD. *p < 0.05, **p < 0.01 vs. control group, #p < 0.05, ##p < 0.01 vs. model group. BV: B. vulgatus; BA: butyric acid; IVA: isovaleric acid; HA: hexanoic acid; IBA: isobutyric acid; AA: acetic acid; PA: propionic acid; VA: valeric acid.

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  Fig. 5. Effects of B. vulgatus on the transcriptomic profile. (A) PCA score plot of each group (n = 3). (B) Hierarchical cluster analysis. (C, D) GO (C) and KEGG (D) functional enrichment analysis. (E, F) The protein expression levels of TGF-β1, p-ERK, p-JNK, and p-p38 MAPK (n = 4, one-way ANOVA). BV: B. vulgatus. Data are shown as mean ± SD. #p < 0.05, ##p < 0.01 vs. control group, *p < 0.05, **p < 0.01 vs. model group.

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  Fig. 6. Effects of B. vulgatus and butyric acid on the cardiac function of ISO-induced hypertrophic and heart failure (HF) model mice. (A, B) Echocardiographic results of each group (n = 5, one-way ANOVA). (C, D) H&E, Masson and WGA staining of each group's cardiac tissue (C) and quantitative results (D). (E) NT-proBNP level in each group (n = 5, one-way ANOVA). BV: B. vulgatus. Data are shown as mean ± SD. ##p < 0.01 vs. control group, *p < 0.05, **p < 0.01 vs. ISO group.

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  Fig. 7. Correlations between butyric acid level and clinical parameters, all-cause mortality in patients. (A) Spearman correlations between B. vulgatus (BV), butyric acid levels and clinical parameters. (B) ROC curve analysis. (C) Kaplan‒Meier survival analysis. BV: B. vulgatus; ALT: alanine aminotransferase; AST: aspartate aminotransferase; TG: triglyceride; TC: total cholesterol; HDL-C: high-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol; Cr: creatinine; UA: uric acid; TSH: thyroid stimulating hormone; FT3: Free triiodothyronine; FT4: free thyroxine; HbA1C: glycosylated hemoglobin; GA: glycated albumin; T4: tetraiodothyronine; T3: triiodothyronine.