Figures & data
Figure 1. Fiber treatments inhibited the increase of blood pressure, target organ hypertrophy but not disease activity in systemic lupus erythematosus (SLE) mice.
Notes: (a) Time-course of systolic blood pressure (SBP) (n = 9-10, data are shown as means ± SEM, **P < 0.01 compared to the CTR group, #P <0.05 and ##P <0.01 compared to the untreated SLE group, two-way ANOVA, Sidak’s multiple comparisons test) and (b) final SBP measured by tail-cuff plethysmography, (c) morphological parameters, (d) circulating double-stranded DNA autoantibodies levels, and (e) splenomegaly in control (CTR), SLE and SLE-groups treated with resistant starch (RS) or inulin-type fructans (ITF). Values are expressed as means ± SEM, n = 9-10, *P < 0.05 and **P < 0.01 compared to the CTR group, #P <0.05 and ##P <0.01 compared to the untreated SLE group, one-way ANOVA.
Figure 2. Fiber treatments improved morphological renal cortex features in systemic lupus erythematosus (SLE) mice.
Notes: (a) Kidney sections in control (CTR), SLE and SLE-groups treated with resistant starch (RS) or inulin-type fructans (ITF) were stained with hematoxylin-eosin and representative images are shown. Bar scale: 500 μm (left panels). Kidney sections were stained with periodic acid-Schiff and glomerular representative images are shown. Bar scale: 50 μm (right panels). Chronic inflammatory infiltrate in medullary area of kidney (black arrows), mesangial matrix expansion of glomeruli (white arrows), and hyaline tubular casts (asterisk). Table shows the quantification of renal lesions. Values are expressed as means ± SEM of percentage of affected glomeruli (n = 50/mouse). The percentage of mice with lesion is expressed in brackets [mice %]. (b) The mean scores for individual pathological features were summed to obtain the three main scores (the glomerular activity score, the tubulointerstitial activity score, and the chronic lesion score). Values are expressed as means ± SEM of relative units (R.U.). **P < 0.01 compared to the CTR group, #P <0.05 and ##P <0.01 compared to the untreated SLE group,one-way ANOVA.
Figure 3. Fiber treatments changed short chain fatty acids (SCFAs) bioavailability in systemic lupus erythematosus (SLE) mice.
Notes: (a) Proportion of SCFAs producing- bacteria in feces from control (CTR), SLE and SLE-groups treated with resistant starch (RS) or inulin-type fructans (ITF) measured by 16S rRNA analysis (n = 8-10). (b) Concentrations of SCFAs in feces from all experimental groups measured by HPLC-ESI-MS and expressed as µmol/g of lyophilized feces. (c) Colonic mRNA levels of monocarboxylate-transporter (MCT)1 and MCT4, and (d) hypoxia inducible factor (HIF)-1. (e) Concentrations of SCFAs in colonic tissue expressed as µmol/g of lyophilized colon, and (f) in plasma from all experimental groups measured by HPLC-ESI-MS and expressed as µmol/L. Values are expressed as means ± SEM, n = 9-10, *P < 0.05 compared to the CTR group, #P <0.05 and ##P <0.01 compared to the untreated SLE group, one-way ANOVA.
Figure 4. Effects of fiber treatments on lymphocytes populations in systemic lupus erythematosus (SLE) mice.
Notes: (a) Total B lymphocytes, T helper (Th) cells, Regulatory T cells (Treg), Th17, and Th1 cells measured by flow cytometry in mesenteric lymphoid nodes, and (b) B and Th cells in spleen from control (CTR), SLE and SLE-groups treated with resistant starch (RS) or inulin-type fructans (ITF). All data are expressed as % of parent, except for B cells, that are represented as % of grandparent (% of CD45+). Values are expressed as means ± SEM, n = 9-10, *P < 0.05 and **P < 0.01 compared to the CTR group, #P <0.05 and ##P <0.01 compared to the untreated SLE group, one-way ANOVA.
Figure 5. Fiber treatments improved endothelial function, NADPH oxidase activity and aortic infiltration of immune cells in systemic lupus erythematosus (SLE) mice.
Notes: (a) Vascular relaxation responses induced by acetylcholine (Ach) in endothelium-intact aortas pre-contracted by U46619 (3 nM), in the absence or in the presence of the NADPH oxidase inhibitor VAS2870 (10 µM) or the Rho kinase inhibitor Y27632 (0.5 µM) in all experimental groups (n = 9-10, data are shown as means ± SEM, *P < 0.05 compared to the CTR group, #P <0.05 compared to the untreated SLE group, two-way ANOVA, Dunnett’s multiple comparisons test). (b) Aortic NADPH oxidase activity measured by lucigenin-enhanced chemiluminescence. (c) Aortic infiltration of immune cells measured by flow cytometry. (d) Aortic mRNA levels of toll-like receptor (TLR)4, G protein-coupled receptor (GPR)43, and histone deacetylase (HDAC)3. Groups: control (CTR), SLE and SLE-groups treated with resistant starch (RS) or inulin-type fructans (ITF). Values are expressed as means ± SEM, n = 9-10, **P < 0.01 compared to the CTR group, #P <0.05 and ##P <0.01 compared to the untreated SLE group, one-way ANOVA.
Figure 6. Fiber treatments prevented the transfer of hypertensive phenotype to germ-free mice induced by inoculation of feces from systemic lupus erythematosus (SLE) mice.
Notes: (a) Systolic blood pressure (SBP) measured by tail-cuff plethysmography. (b) Mean arterial blood pressure (SBP) measured by direct register in carotid artery. (c) Urine protein concentration measured by Combur test strips. (d) Left ventricular weight/tibia length ratio was measured as morphological parameter in the heart. (e) Spleen weight/tibia length ratio, and (f) autoantibody levels were measured as markers of the pathology. Groups: germ-free (GF) inoculated with control feces (GF-CTR), GF inoculated with SLE feces (GF-SLE) and GF inoculated with feces from SLE-groups treated with resistant starch (GF-RS) or with inulin-type fructans (GF-ITF). Values are expressed as means ± SEM, n = 8-10, *P < 0.05 and **P < 0.01 compared to the GF-CTR group, #P <0.05 and ##P <0.01 compared to the GF-SLE group, one-way ANOVA.
Figure 7. Fiber treatments prevented the transfer of endothelial dysfunction phenotype to germ-free mice induced by inoculation of feces from systemic lupus erythematosus (SLE) mice.
Notes: (a) Vascular relaxation responses induced by acetylcholine (Ach) in endothelium-intact aortas pre-contracted by U46619 (3 nM), in the absence or in the presence of the NADPH oxidase inhibitor VAS2870 (10 µM) or the Rho kinase inhibitor Y27632 (0.5 µM) in all experimental groups (n = 8-10, data are shown as means ± SEM, **P < 0.01 compared to the CTR group, ##P <0.01 compared to the untreated SLE group, two-way ANOVA, Dunnett’s multiple comparisons test). (b) Aortic NADPH oxidase activity measured by lucigenin-enhanced chemiluminescence. (c) Aortic infiltration of immune cells measured by flow cytometry. Groups: germ-free (GF) inoculated with control feces (GF-CTR), GF inoculated with SLE feces (GF-SLE) and GF inoculated with feces from SLE-groups treated with resistant starch (GF-RS) or with inulin-type fructans (GF-ITF). Values are expressed as means ± SEM, n = 8-10, *P < 0.05 and **P < 0.01 compared to the GF-CTR group, #P <0.05 compared to the GF-SLE group, one-way ANOVA.
Table 1. Oligonucleotides for real-time RT-PCR.
Table 2. Key antibodies for flow cytometry.
Supplemental material
Supplemental Material
Download MS Word (4.1 MB)Data availability statement
The sequencing dataset from this study have been deposited in ZENODO (Doi: 10.5281/zenodo.7547433).