ABSTRACT
SCOPE: To investigate the efficacy of lingonberries in prevention of atherosclerosis, using atherosclerosis-prone Apoe(-/-) mice and to clarify whether effects were associated with changes in the gut microbiota, gut metabolites, and lipid metabolism. METHODS AND RESULTS: Male Apoe(-/-) mice were fed either low-fat diet, high-fat diet, or high-fat diet with 44% lingonberries for 8 weeks. Blood lipid profiles, hepatic gene expression, atherosclerotic plaques in the aortic root region of the heart, bacterial 16S rRNA gene profiles, and cecal short-chain fatty acids (SCFAs) were analyzed. Triglyceride levels and amount of atherosclerotic plaques decreased in the group fed lingonberries in comparison to the high-fat group. Hepatic expression of the bile acid synthesis gene Cyp7a1 was significantly upregulated in the lingonberry group. Lingonberries increased the cecal relative abundance of bacterial genera Bacteroides, Parabacteroides and Clostridium. The cecal levels of total SCFAs were significantly lower in the lingonberry group, while the cecal proportion of propionic acid was higher in mice fed lingonberries. CONCLUSION: Intake of lingonberries resulted in decreased triglyceridemia and reduced atherosclerosis. The altered gut microbiota composition and SCFA profile was associated with increased hepatic bile acid gene expression in mice fed lingonberries.
Subject(s)
Atherosclerosis/prevention & control , Gastrointestinal Microbiome/drug effects , Plant Preparations/pharmacology , Vaccinium vitis-idaea/chemistry , Animals , Bacteroidetes/drug effects , Cecum/microbiology , Cholesterol/blood , Cholesterol 7-alpha-Hydroxylase/genetics , Cholesterol 7-alpha-Hydroxylase/metabolism , Clostridium/drug effects , Diet, Fat-Restricted , Diet, High-Fat , Dietary Fiber/administration & dosage , Fatty Acids, Volatile/analysis , Gene Expression Regulation , Lipid Metabolism/drug effects , Liver/drug effects , Liver/metabolism , Male , Mice , Mice, Knockout, ApoE , Organ Size/drug effects , Plaque, Atherosclerotic/blood , Plaque, Atherosclerotic/prevention & control , RNA, Ribosomal, 16S/isolation & purification , Receptors, Cytoplasmic and Nuclear/genetics , Receptors, Cytoplasmic and Nuclear/metabolism , Steroid 12-alpha-Hydroxylase/genetics , Steroid 12-alpha-Hydroxylase/metabolism , Triglycerides/bloodABSTRACT
The aim of this study was to investigate how physico-chemical properties of two dietary fibres, guar gum and pectin, affected weight gain, adiposity, lipid metabolism, short-chain fatty acid (SCFA) profiles and the gut microbiota in male Wistar rats fed either low- or high-fat diets for three weeks. Both pectin and guar gum reduced weight gain, adiposity, liver fat and blood glucose levels in rats fed a high-fat diet. Methoxylation degree of pectin (low, LM and high (HM)) and viscosity of guar gum (low, medium or high) resulted in different effects in the rats, where total blood and caecal amounts of SCFA were increased with guar gum (all viscosities) and with high methoxylated (HM) pectin. However, only guar gum with medium and high viscosity increased the levels of butyric acid in caecum and blood. Both pectin and guar gum reduced cholesterol, liver steatosis and blood glucose levels, but to varying extent depending on the degree of methoxylation and viscosity of the fibres. The medium viscosity guar gum was the most effective preparation for prevention of diet-induced hyperlipidaemia and liver steatosis. Caecal abundance of Akkermansia was increased with high-fat feeding and with HM pectin and guar gum of all viscosities tested. Moreover, guar gum had distinct bifidogenic effects independent of viscosity, increasing the caecal abundance of Bifidobacterium ten-fold. In conclusion, by tailoring the viscosity and possibly also the degree of methoxylation of dietary fibre, metabolic effects may be optimized, through a targeted modulation of the gut microbiota and its metabolites.
