The prebiotic fiber inulin ameliorates cardiac, adipose tissue, and hepatic pathology, but exacerbates hypertriglyceridemia in rats with metabolic syndrome

Abstract

Prebiotics ameliorate dysbiosis and influence metabolism and the immune system, but their effects on cardiovascular complications in metabolic disorders remain largely unknown. We here investigated the effects of the soluble fiber inulin on cardiac, adipose tissue, and hepatic pathology as well as on metabolic disorders in DahlS.Z-Leprfa/Leprfa (DS/obese) rats, an animal model of metabolic syndrome (MetS). DS/obese rats and their homozygous lean (DahlS.Z-Lepr+/Lepr+, or DS/lean) littermate controls were fed a purified diet containing 5% or 20% inulin from 9 to 13 weeks of age. The high-fiber diet ameliorated hypertension, left ventricular inflammation, fibrosis, and diastolic dysfunction, attenuated adipose tissue inflammation and fibrosis as well as alleviated the elevation of interleukin-6 levels, without affecting insulin resistance, in DS/obese rats. In addition, high fiber intake ameliorated lipid accumulation, inflammation, and fibrosis, attenuated the reduction in AMPK activity and the up-regulation of sterol regulatory element binding protein-1c gene expression, and further increased the expression of microsomal triglyceride transfer protein gene, in the liver of DS/obese rats. It also mitigated increases in total and non-high-density lipoprotein-cholesterol levels but increased the triglyceride concentration in serum in these rats. None of these parameters was affected by high dietary fiber in DS/lean rats. The proportion of regulatory T cells in adipose tissue was influenced by dietary fiber but not by genotype. Our results indicate that inulin exacerbates hypertriglyceridemia but alleviates hypertension and cardiac injury as well as adipose tissue and hepatic pathology in MetS rats.

The Degree of Inulin Polymerization Is Important for Short-Term Amelioration of High-Fat Diet (HFD)-Induced Metabolic Dysfunction and Gut Microbiota Dysbiosis in Rats

“…Although there appears to be greater anti-inflammatory effects with the administration of inulin 14 , the lack of statistically significant differences between the groups may be due to the shorter 21-day duration of the current study. This was also observed when Komatsu et al reported that 28 days of a high-inulin diet (20% w/w) did not induce statistically significant changes to systemic IL-6, triglyceride, and HDL levels compared to control diet (5% w/w) in DahlS.Z-Lepr fa /Lepr fa (DS/obese) rats [47]. However, a longer 16-week study on HFD-fed (60% of their diet in terms of calories) C57/BL mice supplemented with inulin (10% w/w) found significantly (p < 0.05) lower serum triglyceride, TNF-a, and Il-6 levels, whilst HDL levels remained unchanged [48].…”

Formononetin‐Vitamin E Conjugate Synergistically Supports Adipogenesis, Attenuates Oxidative Stress, and Restores Insulin Sensitization in Differentiated Preadipocytes

“…[41] Altogether, our data reflected that VESylated-FMN synergistically suppresses the HG-stimulated oxidative stress by restoring ΔΨm. Moreover, adiponectin expression and MCP1 attenuation together control the systemic metabolism, [42] which served to corroborate this finding.…”

The dietary fiber guar gum ameliorates experimental autoimmune encephalomyelitis via attenuated Th1 activation and differentiation

“…Invariably, fiber supplementation induces shifts in microbial community composition and function, with a common outcome of increased SCFA availability. The effects of fiber supplementation on host physiology include enhanced numbers and function of CD4 + Treg cells, support of cellular metabolism, and (with few exceptions (Komatsu et al, 2021; Myhill et al, 2020; Prow et al, 2019) restrained inflammatory responses that protect against infectious and non-communicable inflammatory disease models in mice. Some of the studies leading to these insights have analyzed supplementation with single-source high fiber diets (pectin, inulin, cellulose) while others have used mixed fiber sources.…”