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Nature Microbiology Aug 2023Non-alcoholic steatohepatitis (NASH) is the severe form of non-alcoholic fatty liver disease, and is characterized by liver inflammation and fat accumulation. Dietary...
Non-alcoholic steatohepatitis (NASH) is the severe form of non-alcoholic fatty liver disease, and is characterized by liver inflammation and fat accumulation. Dietary interventions, such as fibre, have been shown to alleviate this metabolic disorder in mice via the gut microbiota. Here, we investigated the mechanistic role of the gut microbiota in ameliorating NASH via dietary fibre in mice. Soluble fibre inulin was found to be more effective than insoluble fibre cellulose to suppress NASH progression in mice, as shown by reduced hepatic steatosis, necro-inflammation, ballooning and fibrosis. We employed stable isotope probing to trace the incorporation of C-inulin into gut bacterial genomes and metabolites during NASH progression. Shotgun metagenome sequencing revealed that the commensal Parabacteroides distasonis was enriched by C-inulin. Integration of C-inulin metagenomes and metabolomes suggested that P. distasonis used inulin to produce pentadecanoic acid, an odd-chain fatty acid, which was confirmed in vitro and in germ-free mice. P. distasonis or pentadecanoic acid was protective against NASH in mice. Mechanistically, inulin, P. distasonis or pentadecanoic acid restored gut barrier function in NASH models, which reduced serum lipopolysaccharide and liver pro-inflammatory cytokine expression. Overall this shows that gut microbiota members can use dietary fibre to generate beneficial metabolites to suppress metabolic disease.
Topics: Animals; Mice; Non-alcoholic Fatty Liver Disease; Inulin; Fatty Acids; Inflammation; Dietary Fiber
PubMed: 37386075
DOI: 10.1038/s41564-023-01418-7 -
The American Journal of Clinical... Mar 2024Weight loss is the most effective treatment for nonalcoholic fatty liver disease (NAFLD). There is evidence that the Mediterranean diets rich in unsaturated fatty acids... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Weight loss is the most effective treatment for nonalcoholic fatty liver disease (NAFLD). There is evidence that the Mediterranean diets rich in unsaturated fatty acids and fiber have beneficial effects on weight homeostasis and metabolic risk factors in individuals with NAFLD. Studies have also shown that higher circulating concentrations of pentadecanoic acid (C15:0) are associated with a lower risk for NAFLD.
OBJECTIVES
To examine the effects of a Mediterranean-like, culturally contextualized Asian diet rich in fiber and unsaturated fatty acids, with or without C15:0 supplementation, in Chinese females with NAFLD.
METHODS
In a double-blinded, parallel-design, randomized controlled trial, 88 Chinese females with NAFLD were randomly assigned to 1 of the 3 groups for 12 wk: diet with C15:0 supplementation (n = 31), diet without C15:0 supplementation (n = 28), or control (habitual diet and no C15:0 supplementation, n = 29). At baseline and after the intervention, body fat percentage, intrahepatic lipid content, muscle and abdominal fat, liver enzymes, cardiometabolic risk factors, and gut microbiome were assessed.
RESULTS
In the intention-to-treat analysis, weight reductions of 4.0 ± 0.5 kg (5.3%), 3.4 ± 0.5 kg (4.5%), and 1.5 ± 0.5 kg (2.1%) were achieved in the diet-with-C15:0, diet without-C15:0, and the control groups, respectively. The proton density fat fraction (PDFF) of the liver decreased by 33%, 30%, and 10%, respectively. Both diet groups achieved significantly greater reductions in body weight, liver PDFF, total cholesterol, gamma-glutamyl transferase, and triglyceride concentrations compared with the control group. C15:0 supplementation reduced LDL-cholesterol further, and increased the abundance of Bifidobacterium adolescentis. Fat mass, visceral adipose tissue, subcutaneous abdominal adipose tissue (deep and superficial), insulin, glycated hemoglobin, and blood pressure decreased significantly in all groups, in parallel with weight loss.
CONCLUSION
Mild weight loss induced by a Mediterranean-like diet adapted for Asians has multiple beneficial health effects in females with NAFLD. C15:0 supplementation lowers LDL-cholesterol and may cause beneficial shifts in the gut microbiome.
TRIAL REGISTRATION NUMBER
This trial was registered at the clinicaltrials.gov as NCT05259475.
Topics: Female; Humans; Non-alcoholic Fatty Liver Disease; Diet, Mediterranean; Liver; Weight Loss; Fatty Acids, Unsaturated; Cholesterol; Fatty Acids
PubMed: 38035997
DOI: 10.1016/j.ajcnut.2023.11.013 -
Nutrients Oct 2023Pentadecanoic acid (C15:0) is an essential odd-chain saturated fatty acid with broad activities relevant to protecting cardiometabolic, immune, and liver health. C15:0...
Pentadecanoic acid (C15:0) is an essential odd-chain saturated fatty acid with broad activities relevant to protecting cardiometabolic, immune, and liver health. C15:0 activates AMPK and inhibits mTOR, both of which are core components of the human longevity pathway. To assess the potential for C15:0 to enhance processes associated with longevity and healthspan, we used human cell-based molecular phenotyping assays to compare C15:0 with three longevity-enhancing candidates: acarbose, metformin, and rapamycin. C15:0 (n = 36 activities in 10 of 12 cell systems) and rapamycin (n = 32 activities in 12 of 12 systems) had the most clinically relevant, dose-dependent activities. At their optimal doses, C15:0 (17 µM) and rapamycin (9 µM) shared 24 activities across 10 cell systems, including anti-inflammatory (e.g., lowered MCP-1, TNFα, IL-10, IL-17A/F), antifibrotic, and anticancer activities, which are further supported by previously published in vitro and in vivo studies. Paired with prior demonstrated abilities for C15:0 to target longevity pathways, hallmarks of aging, aging rate biomarkers, and core components of type 2 diabetes, heart disease, cancer, and nonalcoholic fatty liver disease, our results support C15:0 as an essential nutrient with activities equivalent to, or surpassing, leading longevity-enhancing candidate compounds.
Topics: Humans; Longevity; Diabetes Mellitus, Type 2; Fatty Acids, Essential; Sirolimus
PubMed: 37960259
DOI: 10.3390/nu15214607 -
Food & Nutrition Research 2021Saturated fatty acids (SFAs) generally have been thought to worsen insulin-resistance and increase the risk of developing type 2 diabetes mellitus (T2DM). Recently,...
BACKGROUND
Saturated fatty acids (SFAs) generally have been thought to worsen insulin-resistance and increase the risk of developing type 2 diabetes mellitus (T2DM). Recently, accumulating evidence has revealed that SFAs are not a single homogeneous group, instead different SFAs are associated with T2DM in opposing directions. Pentadecanoic acid (C15:0, PA) is directly correlated with dairy products, and a negative association between circulating PA and metabolic disease risk was observed in epidemiological studies. Therefore, the role of PA in human health needs to be reinforced. Whether PA has a direct benefit on glucose metabolism and insulin sensitivity needs further investigation.
OBJECTIVE
The present study aimed to investigate the effect and potential mechanism of action of PA on basal and insulin stimulated glucose uptake in C2C12 myotubes.
METHODS
Glucose uptake was determined using a 2-(N-[7-nitrobenz-2-oxa-1,3-diazol-4-yl] amino)-2-deoxyglucose (2-NBDG) uptake assay. Cell membrane proteins were isolated and glucose transporter 4 (GLUT4) protein was detected by western blotting to examine the translocation of GLUT4 to the plasma membrane. The phosphorylation levels of proteins involved in the insulin and 5'-adenosine monophosphate-activated protein kinase (AMPK) pathways were examined by western blotting.
RESULTS
We found that PA significantly promoted glucose uptake and GLUT4 translocation to the plasma membrane. PA had no effect on the insulin-dependent pathway involving insulin receptor substrate 1 (Tyr632) and protein kinase B (PKB/Akt), but increased phosphorylation of AMPK and Akt substrate of 160 kDa (AS160). Compound C (an AMPK inhibitor) blocked PA-induced AMPK activation and reversed PA-induced GLUT4 translocation, indicating that PA promotes glucose uptake via the AMPK pathway . Moreover, PA significantly promoted insulin-stimulated glucose uptake in myotubes. Under insulin stimulation, PA did not affect the insulin-dependent pathway, but still activated AMPK.
CONCLUSION
PA, an odd-chain SFA, significantly stimulates glucose uptake via the AMPK-AS160 pathway and exhibits an insulin-sensitizing effect in myotubes.
PubMed: 33613155
DOI: 10.29219/fnr.v65.4527 -
Research in Microbiology 2021The ability to form biofilms is a common feature of microorganisms, which can colonize a variety of surfaces, such as host tissues and medical devices, resulting in...
The ability to form biofilms is a common feature of microorganisms, which can colonize a variety of surfaces, such as host tissues and medical devices, resulting in infections highly resistant to conventional drugs. This aspect is particularly critical in polymicrobial biofilms involving both fungi and bacteria, therefore, to eradicate such severe infections, new and effective anti-biofilm strategies are needed. The efficacy of pentadecanal and pentadecanoic acid as anti-biofilm agents has been recently reported against different bacterial strains. Their chemical similarity with diffusible signal factors (DSFs), plus the already known ability of fatty acids to act as anti-biofilm agents, suggested to explore their use against Candida albicans and Klebsiella pneumoniae mixed biofilm. In this work, we demonstrated the ability of both molecules to prevent the formation and destabilize the structure of the dual-species biofilm. Moreover, the pentadecanoic acid anti-biofilm coating, previously developed through the adsorption of the fatty acid on polydimethylsiloxane (PDMS), was proved to prevent the polymicrobial biofilm formation in dynamic conditions by confocal laser scanning microscopy analysis. Finally, the evaluation of the expression levels of some biofilm-related genes of C. albicans and K. pneumoniae treated with pentadecanoic acid provided some insights into the molecular mechanisms underpinning its anti-biofilm effect.
Topics: Aldehydes; Anti-Bacterial Agents; Biofilms; Candida albicans; Dimethylpolysiloxanes; Fatty Acids; Gene Expression; Genes, Bacterial; Genes, Fungal; Klebsiella pneumoniae; Microbial Sensitivity Tests
PubMed: 34563667
DOI: 10.1016/j.resmic.2021.103880 -
Nutrients Jun 2020Saturated fatty acids possess few health benefits compared to unsaturated fatty acids. However, increasing experimental evidence demonstrates the nutritionally...
Saturated fatty acids possess few health benefits compared to unsaturated fatty acids. However, increasing experimental evidence demonstrates the nutritionally beneficial role of odd-chain saturated fatty acids in human health. In this study, the anti-cancer effects of pentadecanoic acid were evaluated in human breast carcinoma MCF-7/stem-like cells (SC), a cell line with greater mobility, invasiveness, and cancer stem cell properties compared to the parental MCF-7 cells. Pentadecanoic acid exerted selective cytotoxic effects in MCF-7/SC compared to in the parental cells. Moreover, pentadecanoic acid reduced the stemness of MCF-7/SC and suppressed the migratory and invasive ability of MCF-7/SC as evidenced by the results of flow cytometry, a mammosphere formation assay, an aldehyde dehydrogenase activity assay, and Western blot experiments conducted to analyze the expression of cancer stem cell markers-CD44, β-catenin, MDR1, and MRP1-and epithelial-mesenchymal transition (EMT) markers-snail, slug, MMP9, and MMP2. In addition, pentadecanoic acid suppressed interleukin-6 (IL-6)-induced JAK2/STAT3 signaling, induced cell cycle arrest at the sub-G1 phase, and promoted caspase-dependent apoptosis in MCF-7/SC. These findings indicate that pentadecanoic acid can serve as a novel JAK2/STAT3 signaling inhibitor in breast cancer cells and suggest the beneficial effects of pentadecanoic acid-rich food intake during breast cancer treatments.
Topics: ATP Binding Cassette Transporter, Subfamily B; Antineoplastic Agents; Apoptosis; Biomarkers, Tumor; Breast Neoplasms; Cell Transformation, Neoplastic; Epithelial-Mesenchymal Transition; Fatty Acids; Humans; Hyaluronan Receptors; Janus Kinase 2; MCF-7 Cells; Matrix Metalloproteinase 9; STAT3 Transcription Factor; Signal Transduction; Snail Family Transcription Factors; beta Catenin
PubMed: 32503225
DOI: 10.3390/nu12061663 -
International Journal of Molecular... Sep 2022Estrogen receptors are indicators of breast cancer adaptability to endocrine therapies, such as tamoxifen. Deficiency or absence of estrogen receptor α (ER-α) in...
Estrogen receptors are indicators of breast cancer adaptability to endocrine therapies, such as tamoxifen. Deficiency or absence of estrogen receptor α (ER-α) in breast cancer cells results in reduced efficacy of endocrine therapy. Here, we investigated the effect of combined tamoxifen and pentadecanoic acid therapy on ER-α-under-expressing breast cancer cells. Drug resistance gene expression patterns were determined by RNA sequencing analysis and in vitro experiments. For the first time, we demonstrate that the combined treatment of pentadecanoic acid, an odd-chain fatty acid, and tamoxifen synergistically suppresses the growth of human breast carcinoma MCF-7 stem cells (MCF-7/SCs), which were found to be tamoxifen-resistant and showed reduced ER-α expression compared with the parental MCF-7 cells. In addition, the combined treatment synergistically induced apoptosis and accumulation of sub-G1 cells and suppressed epithelial-to-mesenchymal transition (EMT). Exposure to this combination induces re-expression of ER-α at the transcriptional and protein levels, along with suppression of critical survival signal pathways, such as ERK1/2, MAPK, EGFR, and mTOR. Collectively, decreased ER-α expression was restored by pentadecanoic acid treatment, resulting in reversal of tamoxifen resistance. Overall, pentadecanoic acid exhibits the potential to enhance the efficacy of endocrine therapy in the treatment of ER-α-under-expressing breast cancer cells.
Topics: Antineoplastic Agents, Hormonal; Breast Neoplasms; Cell Line, Tumor; Drug Resistance, Neoplasm; ErbB Receptors; Estrogen Receptor alpha; Fatty Acids; Female; Humans; MCF-7 Cells; Receptors, Estrogen; TOR Serine-Threonine Kinases; Tamoxifen
PubMed: 36232636
DOI: 10.3390/ijms231911340 -
Frontiers in Cellular and Infection... 2022Chronic atrophic gastritis (CAG), premalignant lesions of gastric cancer (GC), greatly increases the risk of GC. Gastroscopy with tissue biopsy is the most commonly used...
BACKGROUND
Chronic atrophic gastritis (CAG), premalignant lesions of gastric cancer (GC), greatly increases the risk of GC. Gastroscopy with tissue biopsy is the most commonly used technology for CAG diagnosis. However, due to the invasive nature, both ordinary gastroscope and painless gastroscope result in a certain degree of injury to the esophagus as well as inducing psychological pressure on patients. In addition, patients need fast for at least half a day and take laxatives.
METHODS
In this study, fecal metabolites and microbiota profiles were detected by metabolomics and 16S rRNA V4-V5 region sequencing.
RESULTS
Alteration of fecal metabolites and microbiota profiles was found in CAG patients, compared with healthy volunteers. To identify the most relevant features, 7 fecal metabolites and 4 microbiota were selected by random forest (RF), from A and B sample sets, respectively. Furthermore, we constructed support vector machines (SVM) classifification model using 7 fecal metabolites or 4 gut microbes, or 7 fecal metabolites with 4 gut microbes, respectively, on C sample set. The accuracy of classifification model was 0.714, 0.857, 0.857, respectively, and the AUC was 0.71, 0.88, 0.9, respectively. In C sample set, Spearman's rank correlation analysis demonstrated heptadecanoic acid and pentadecanoic acid were signifificantly negatively correlated to and , respectively. We constructed SVM classifification model using 2 correlated fecal metabolites and 2 correlated gut microbes on C sample set. The accuracy of classification model was 0.857, and the AUC was 0.88.
CONCLUSION
Therefore, heptadecanoic acid and pentadecanoic acid, crosstalk with fecal-derived gut microbiota namely Erysipelotrichaceae_UCG-003 and Haemophilus, are potential non-invasive biomarkers for CAG diagnosis.
Topics: Humans; Gastrointestinal Microbiome; Gastritis, Atrophic; RNA, Ribosomal, 16S; Feces; Biomarkers; Firmicutes
PubMed: 36699724
DOI: 10.3389/fcimb.2022.1064737