A High-Fat Diet Increases Gut Microbiota Biodiversity and Energy Expenditure Due to Nutrient Difference

Abstract

A high-fat diet (HFD) can easily induce obesity and change the gut microbiota and its metabolites. However, studies on the effects of high-fat diets on the host have drawn inconsistent results. In this study, the unexpected results showed that the refined HFD increased gut microbiota diversity and short-chain fatty acids (SCFAs), causing an increase in energy metabolism. Further analysis revealed these changes were caused by the different fiber content in these two diets. Male C57BL/6J mice (4–5 weeks old) were fed either HFD or refined low-fat diet (LFD) for 14 weeks. The metabolic rates, thermogenesis, gut microbiome, and intestinal SCFAs were tested. The HFD triggered obesity and disturbed glucose homeostasis. Mice fed HFD ingested more fiber than mice fed LFD (p < 0.0001), causing higher intestinal SCFA concentrations related to the increased abundances of specific bacteria in the HFD group. Also, the HFD increased metabolic heat and up-regulated thermogenesis genes uncoupling protein 1(Ucp-1), peroxisome proliferator-activated receptor-γ coactivator-1α (Pgc-1α) expression in the brown adipose tissue (BAT). It was revealed by 16S rRNA gene sequencing that the HFD increased gut microbial diversity, which enriched Desulfovibrionaceae, Rikenellaceae RC9 gut group, and Mucispirillum, meanwhile, reduced the abundance of Lactobacillus, Bifidobacterium, Akkermansia, Faecalibaculum, and Blautia. The predicted metabolic pathways indicated HFD increased the gene expression of non-absorbed carbohydrate metabolism pathways, as well as the risks of colonization of intestinal pathogens and inflammation. In conclusion, the HFD was obesogenic in male C57BL/6J mice, and increased fiber intake from the HFD drove an increase in gut microbiota diversity, SCFAs, and energy expenditure. Meanwhile, the differences in specific nutrient intake can dissociate broad changes in energy expenditure, gut microbiota, and its metabolites from obesity, raising doubts in the previous studies. Therefore, it is necessary to consider whether differences in specific nutrient intake will interfere with the results of the experiments.

Bifidobacterium adolescentis Isolated from Different Hosts Modifies the Intestinal Microbiota and Displays Differential Metabolic and Immunomodulatory Properties in Mice Fed a High-Fat Diet

“…The cages were replaced twice a week to maintain a clean environment. At the end of the experiment, the mice were killed by euthanasia after being fasted for 12 h [ 16 ]. Fresh blood was collected, left to stand for 2 h, and then centrifuged (at 1000× g and 4 °C for 15 min) to isolate serum.…”

“…A quantitative real-time polymerase chain reaction (PCR) was performed in a BioRad thermocycler using the qPCR Master Mix (Vazyme Biotech Co., Ltd, Nanjing, China) and the primer sequences listed in Table S2 . PCR programs and data analyses were based on the previous study [ 16 ].…”

“…The total DNA of the cecal and colonic microbiota was extracted and used for PCR amplification of the V3–V4 regions of their respective 16S rRNA genes. Amplicon sequencing, sequence analysis, and function prediction were performed according to the previous study [ 16 ]. The sequencing reads were processed by the QIIME2 plugin DADA2.…”

“…To quantify SCFAs in cecal and colonic contents, fresh intestinal contents were freeze-dried before weighing, and then SCFAs were quantified as reported in the previous study [ 16 ].…”

The gut microbiota during the progression of atherosclerosis in the perimenopausal period shows specific compositional changes and significant correlations with circulating lipid metabolites

“…Abnormal diet leads to changes in gut microbiota, and the correlation between diet-induced changes in gut microbiota and changes in metabolites has been confirmed. 52 Regulating gut microbiota may be a potential anti-hypercholesterolemia and hyperlipidemia therapy. 53 Aggravated AS injury caused by estrogen loss during menopause has been strongly related with the gut microbiota 29 or dyslipidemia.…”