RESUMEN
The inhabitants of our intestines, collectively called the gut microbiome, comprise fungi, viruses, and bacterial strains. These microorganisms are involved in the fermentation of dietary compounds and the regulation of our adaptive and innate immune systems. Less known is the reciprocal interaction between the gut microbiota and type 2 diabetes mellitus (T2DM), as well as their role in modifying therapies to reduce associated morbidity and mortality. In this review, we aim to discuss the existing literature on gut microbial strains and their diet-derived metabolites involved in T2DM. We also explore the potential diagnostics and therapeutic avenues the gut microbiota presents for targeted T2DM management. Personalized treatment plans, driven by diet and medication based on the patient's microbiome and clinical markers, could optimize therapy.
Asunto(s)
Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Diabetes Mellitus Tipo 2/microbiología , Humanos , Dieta , Bacterias/metabolismo , Bacterias/clasificación , Animales , Disbiosis/microbiologíaRESUMEN
AIMS/HYPOTHESIS: Post-bariatric hypoglycemia (PBH) is caused by postprandial hyperinsulinemia, due to anatomical alterations and changes in post-prandial metabolism after bariatric surgery. The mechanisms underlying the failing regulatory and compensatory systems are unclear. In this study, we investigated the differences in post-prandial hormones and metabolic profiles between patients with and without PBH. METHODS: We performed a mixed meal test (MMT) in 63 subjects before and 1 year after Roux-en-Y gastric bypass (RYGB) surgery. Blood was withdrawn at 0, 10, 20, 30, 60, and 120 min after ingestion of a standardized meal. Glucose, insulin, GLP-1, FGF-19, and FGF-21 were measured and untargeted metabolomics analysis was performed on blood plasma to analyze which hormonal and metabolic systems were altered between patients with and without PBH. RESULTS: Out of 63, a total of 21 subjects (33%) subjects developed PBH (glucose < 3.1 mmol/L) after surgery. Decreased glucose and increased insulin excursions during MMT were seen in PBH (p < 0.05). GLP-1, FGF-19, and FGF-21 were elevated after surgery (p < 0.001), but did not differ between PBH and non-PBH groups. We identified 20 metabolites possibly involved in carbohydrate metabolism which differed between the two groups, including increased carnitine and acylcholines in PBH. CONCLUSION: Overall, 33% of the subjects developed PBH 1 year after RYGB surgery. While GLP-1, FGF-19, and FGF-21 were similar in PBH and non-PBH patients, metabolomics analysis revealed changes in carnitine and acyclcholines that are possibly involved in energy metabolism, which may play a role in the occurrence of PBH.
RESUMEN
BACKGROUND: Bariatric surgery is an effective treatment option for obesity and provides long-term weight loss and positive effects on metabolism, but the underlying mechanisms are poorly understood. Alterations in bile acid metabolism have been suggested as a potential contributing factor, but comprehensive studies in humans are lacking. METHODS: In this study, we analysed the postprandial responses of bile acids, C4 and FGF19 in plasma, and excretion of bile acids in faeces, before and after bariatric surgery in patients (n = 38; 74% females) with obesity with or without type 2 diabetes from the BARIA cohort. FINDINGS: We observed that total fasting plasma bile acid levels increased, and faecal excretion of bile acids decreased after surgery suggesting increased reabsorption of bile acids. Consistent with increased bile acid levels after surgery we observed increased postprandial levels of FGF19 and suppression of the bile acid synthesis marker C4, suggesting increased FXR activation in the gut. We also noted that a subset of bile acids had altered postprandial responses before and after surgery. Finally, fasting plasma levels of 6α-hydroxylated bile acids, which are TGR5 agonists and associated with improved glucose metabolism, were increased after surgery and one of them, HDCA, covaried with diabetes remission in an independent cohort. INTERPRETATION: Our findings provide new insights regarding bile acid kinetics and suggest that bariatric surgery in humans alters bile acid profiles leading to activation of FXR and TGR5, which may contribute to weight loss, improvements in glucose metabolism, and diabetes remission. FUNDING: Novo Nordisk Fonden, Leducq Foundation, Swedish Heart-Lung Foundation, Knut and Alice Wallenberg Foundation, the ALF-agreement, ZonMw.
Asunto(s)
Cirugía Bariátrica , Ácidos y Sales Biliares , Diabetes Mellitus Tipo 2 , Factores de Crecimiento de Fibroblastos , Obesidad , Humanos , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/cirugía , Diabetes Mellitus Tipo 2/sangre , Ácidos y Sales Biliares/metabolismo , Ácidos y Sales Biliares/sangre , Cirugía Bariátrica/métodos , Femenino , Masculino , Obesidad/cirugía , Obesidad/metabolismo , Obesidad/sangre , Persona de Mediana Edad , Adulto , Factores de Crecimiento de Fibroblastos/sangre , Factores de Crecimiento de Fibroblastos/metabolismo , Periodo Posprandial , Biomarcadores , Heces/química , Cinética , AyunoRESUMEN
BACKGROUND AND AIMS: Bile acids (BA) are vital regulators of metabolism. BAs are AQ6 secreted in the small intestine, reabsorbed, and transported back to the liver, where they can modulate metabolic functions. There is a paucity of data regarding the portal BA composition in humans. This study aimed to address this knowledge gap by investigating portal BA composition and the relation with peripheral and fecal BA dynamics in conjunction with the gut microbiome. APPROACH AND RESULTS: Thirty-three individuals from the BARIA cohort were included. Portal plasma, peripheral plasma, and feces were collected. BA and C4 levels were measured employing mass spectrometry. FGF19 was measured using ELISA. Gut microbiota composition was determined through metagenomics analysis on stool samples. Considerable diversity in the portal BA composition was observed. The majority (n = 26) of individuals had a 9-fold higher portal than peripheral BA concentration. In contrast, 8 individuals showed lower portal BA concentration compared with peripheral and had higher levels of unconjugated and secondary BA in this compartment, suggesting more distal origin. The altered portal BA profile was associated with altered gut microbiota composition. In particular, taxa within Bacteroides were reduced in abundance in the feces of these individuals. CONCLUSIONS: Characterization of the portal BA composition in relation to peripheral and fecal BA increased insight into the dynamics of BA metabolism in individuals with obesity. Peripheral BA composition was much more diverse due to microbial metabolism. About 24% of the portal samples was surprisingly low in total BA; the underlying mechanism requires further exploration.
RESUMEN
The gut microbiome exerts metabolic actions on distal tissues and organs outside the intestine, partly through microbial metabolites that diffuse into the circulation. The disruption of gut homeostasis results in changes to microbial metabolites, and more than half of the variance in the plasma metabolome can be explained by the gut microbiome. Ethanol is a major microbial metabolite that is produced in the intestine of nearly all individuals; however, elevated ethanol production is associated with pathological conditions such as metabolic dysfunction-associated steatotic liver disease and auto-brewery syndrome, in which the liver's capacity to metabolize ethanol is surpassed. In this Review, we describe the mechanisms underlying excessive ethanol production in the gut and the role of ethanol catabolism in mediating pathogenic effects of ethanol on the liver and host metabolism. We conclude by discussing approaches to target excessive ethanol production by gut bacteria.
Asunto(s)
Etanol , Microbioma Gastrointestinal , Humanos , Etanol/metabolismo , Microbioma Gastrointestinal/fisiología , Hígado/metabolismo , Hepatopatías Alcohólicas/metabolismoRESUMEN
OBJECTIVE: p63 is a transcription factor involved in multiple biological functions. In the liver, the TAp63 isoform induces lipid accumulation in hepatocytes. However, the role of liver TAp63 in the progression of metabolic dysfunction-associated steatohepatitis (MASH) with fibrosis is unknown. METHODS: We evaluated the hepatic p63 levels in different mouse models of steatohepatitis with fibrosis induced by diet. Next, we used virogenetic approaches to manipulate the expression of TAp63 in adult mice under diet-induced steatohepatitis with fibrosis and characterized the disease condition. Finally, we performed proteomics analysis in mice with overexpression and knockdown of hepatic TAp63. RESULTS: Levels of TAp63, but not of ΔN isoform, are increased in the liver of mice with diet-induced steatohepatitis with fibrosis. Both preventive and interventional strategies for the knockdown of hepatic TAp63 significantly ameliorated diet-induced steatohepatitis with fibrosis in mice fed a methionine- and choline-deficient diet (MCDD) and choline deficient and high fat diet (CDHFD). The overexpression of hepatic TAp63 in mice aggravated the liver condition in mice fed a CDHFD. Proteomic analysis in the liver of these mice revealed alteration in multiple proteins and pathways, such as oxidative phosphorylation, antioxidant activity, peroxisome function and LDL clearance. CONCLUSIONS: These results indicate that liver TAp63 plays a critical role in the progression of diet-induced steatohepatitis with fibrosis, and its inhibition ameliorates the disease.
Asunto(s)
Hígado Graso , Cirrosis Hepática , Hígado , Ratones Endogámicos C57BL , Animales , Ratones , Hígado/metabolismo , Hígado/patología , Masculino , Cirrosis Hepática/metabolismo , Cirrosis Hepática/patología , Hígado Graso/metabolismo , Hígado Graso/patología , Modelos Animales de Enfermedad , Dieta Alta en Grasa/efectos adversos , Transactivadores/metabolismo , Transactivadores/genética , Proteómica , Metionina/deficiencia , Metionina/metabolismoRESUMEN
AIMS/HYPOTHESIS: The prevalence and severity of metabolic dysfunction-associated steatotic liver disease (MASLD) in type 1 diabetes remain unclear. Therefore, we investigated the prevalence and severity of MASLD in type 1 diabetes and assessed which clinical features are most important in predicting MASLD severity. METHODS: A total of 453 individuals with type 1 diabetes (41.6 ± 15.0 years, 64% female, body mass index [BMI] 25.4 ± 4.2â kg/m2, and HbA1c 55.6 ± 12â mmol/mol) underwent vibration-controlled transient elastography (VCTE), with a controlled attenuation parameter (CAP) score for steatosis (≥280.0â dB/m) and a liver stiffness measurement (LMS) for fibrosis (≥8.0â kPa). A machine learning Extra-Trees classification model was performed to assess the predictive power of the clinical features associated with type 1 diabetes with respect to steatosis and fibrosis. RESULTS: The prevalence of hepatic steatosis and fibrosis was 9.5% (95% CI, 6.8-12.2) and 3.5% (95% CI, 1.8-5.2). Higher LMS was associated with a longer duration of type 1 diabetes (median 30.5 [IQR 18.0-39.3] years vs 15.0 [IQR 6.0-27.0] years), and individuals were older, had a higher BMI (mean 27.8 ± 5.2 vs 25.3 ± 4.1â kg/m2), and a higher CAP score (mean 211.4 ± 51.7â dB/m vs 241.4 ± 75.6â dB/m). The most important predictive features of fibrosis were duration of type 1 diabetes, age, and systolic blood pressure, with a mean ± SD area under the curve of 0.73 ± 0.03. CONCLUSION: Individuals with type 1 diabetes and high blood pressure, older age, higher BMI, and longer duration of disease could be considered at high-risk for developing MASLD.
Asunto(s)
Diabetes Mellitus Tipo 1 , Hígado Graso , Humanos , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 1/complicaciones , Femenino , Masculino , Adulto , Prevalencia , Persona de Mediana Edad , Hígado Graso/epidemiología , Hígado Graso/complicaciones , Diagnóstico por Imagen de Elasticidad , Índice de Severidad de la Enfermedad , Índice de Masa Corporal , Cirrosis Hepática/epidemiología , Cirrosis Hepática/diagnóstico por imagenRESUMEN
Metabolic-dysfunction-associated steatotic liver disease (MASLD) is a growing health problem for which no therapy exists to date. The modulation of the gut microbiome may have treatment potential for MASLD. Here, we investigated Anaerobutyricum soehngenii, a butyrate-producing anaerobic bacterium with beneficial effects in metabolic syndrome, in a diet-induced MASLD mouse model. Male C57BL/6J mice received a Western-type high-fat diet and water with 15% fructose (WDF) to induce MASLD and were gavaged with A. soehngenii (108 or 109 colony-forming units (CFU) 3 times per week) or a placebo for 6 weeks. The A. soehngenii gavage increased the cecal butyrate concentrations. Although there was no effect on histological MASLD scores, A. soehngenii improved the glycemic response to insulin. In the liver, the WDF-associated altered expression of three genes relevant to the MASLD pathophysiology was reversed upon treatment with A. soehngenii: Lipin-1 (Lpin1), insulin-like growth factor binding protein 1 (Igfbp1) and Interleukin 1 Receptor Type 1 (Il1r1). A. soehngenii administration also increased the intestinal expression of gluconeogenesis and fructolysis genes. Although these effects did not translate into significant histological improvements in MASLD, these results provide a basis for combined gut microbial approaches to induce histological improvements in MASLD.
Asunto(s)
Clostridiales , Hígado Graso , Enfermedades Metabólicas , Masculino , Animales , Ratones , Ratones Endogámicos C57BL , Composición de Base , Gluconeogénesis , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Hígado Graso/etiología , Hígado Graso/genética , Butiratos , Expresión Génica , Fosfatidato FosfatasaRESUMEN
BACKGROUND: Glycemic control is an important goal of bariatric surgery in patients with type 2 diabetes mellitus (T2DM) and obesity. The laparoscopic one-anastomosis gastric bypass (OAGB) has potential metabolic benefits over the laparoscopic Roux-en-Y gastric bypass (RYGB). Aim of this study is to examine whether RYGB or OAGB grants better glycemic control 12 months post-surgery. METHODS: For this retrospective cohort study, patients with T2DM and obesity, who underwent primary OAGB between 2008 and 2017 were reviewed. For each OAGB patient, three primary RYGB patients were matched for age, gender and body mass index (BMI). Glycemic control was expressed by the glycated hemoglobin (HbA1c), which was measured pre- and 12 months post-operatively. Weight loss was reported in percentage total weight loss (%TWL). RESULTS: A total of 152 patients, of whom 38 had OAGB and 114 RYGB, were included. Mean (standard deviation (SD)) HbA1c was 7.49 (1.51)% in the OAGB group and 7.56(1.23)% in the RYGB group at baseline. Twelve months after surgery the mean (SD) HbA1c dropped to 5.73 (0.71)% after OAGB and 6.09 (0.76)% after RYGB (adjusted p = 0.011). The mean (SD) BMI was reduced from 42.5(6.3) kg/m2 to 29.6(4.7) kg/m2 after OAGB and 42.3(5.8) kg/m2 to 29.9 (4.5) kg/m2 after RYGB; reflecting 30.3 (6.8) %TWL post-OAGB and 29.0 (7.3) %TWL post-RYGB (p = 0.34). CONCLUSION: This study indicates that OAGB leads to lower HbA1c one year after surgery compared to RYGB, without a difference in weight loss. Prospective (randomized) studies are needed to ascertain the most optimal metabolic treatment for patients with obesity and T2DM.
Asunto(s)
Diabetes Mellitus Tipo 2 , Derivación Gástrica , Laparoscopía , Obesidad Mórbida , Humanos , Derivación Gástrica/efectos adversos , Obesidad Mórbida/cirugía , Hemoglobina Glucada , Estudios Retrospectivos , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/cirugía , Estudios Prospectivos , Estudios de Cohortes , Obesidad/cirugía , Obesidad/etiología , Pérdida de PesoRESUMEN
Humans possess abundant amounts of microorganisms, including bacteria, fungi, viruses, and archaea, in their gut. Patients with nonalcoholic fatty liver disease (NAFLD) exhibit alterations in their gut microbiome and an impaired gut barrier function. Preclinical studies emphasize the significance of the gut microbiome in the pathogenesis of NAFLD. In this overview, we explore how adjusting the gut microbiome could serve as an innovative therapeutic strategy for NAFLD. We provide a summary of current information on untargeted techniques such as probiotics and fecal microbiota transplantation, as well as targeted microbiome-focused therapies including engineered bacteria, prebiotics, postbiotics, and phages for the treatment of NAFLD.
Asunto(s)
Microbioma Gastrointestinal , Microbiota , Enfermedad del Hígado Graso no Alcohólico , Probióticos , Humanos , Enfermedad del Hígado Graso no Alcohólico/microbiología , Probióticos/uso terapéutico , Prebióticos , Bacterias/genética , Hígado/patologíaRESUMEN
Primary and secondary bile acids (BAs) influence metabolism and inflammation, and the gut microbiome modulates levels of BAs. We systematically explore the host genetic, gut microbial, and habitual dietary contribution to a panel of 19 serum and 15 stool BAs in two population-based cohorts (TwinsUK, n = 2,382; ZOE PREDICT-1, n = 327) and assess changes post-bariatric surgery and after nutritional interventions. We report that BAs have a moderately heritable genetic component, and the gut microbiome accurately predicts their levels in serum and stool. The secondary BA isoursodeoxycholate (isoUDCA) can be explained mostly by gut microbes (area under the receiver operating characteristic curve [AUC] = â¼80%) and associates with post-prandial lipemia and inflammation (GlycA). Furthermore, circulating isoUDCA decreases significantly 1 year after bariatric surgery (ß = -0.72, p = 1 × 10-5) and in response to fiber supplementation (ß = -0.37, p < 0.03) but not omega-3 supplementation. In healthy individuals, isoUDCA fasting levels correlate with pre-meal appetite (p < 1 × 10-4). Our findings indicate an important role for isoUDCA in lipid metabolism, appetite, and, potentially, cardiometabolic risk.
Asunto(s)
Cirugía Bariátrica , Ácidos y Sales Biliares , Humanos , Apetito , Cirugía Bariátrica/efectos adversos , Heces , InflamaciónRESUMEN
Weight loss through bariatric surgery is efficient for treatment or prevention of obesity related diseases such as type 2 diabetes and cardiovascular disease. Long term weight loss response does, however, vary among patients undergoing surgery. Thus, it is difficult to identify predictive markers while most obese individuals have one or more comorbidities. To overcome such challenges, an in-depth multiple omics analyses including fasting peripheral plasma metabolome, fecal metagenome as well as liver, jejunum, and adipose tissue transcriptome were performed for 106 individuals undergoing bariatric surgery. Machine leaning was applied to explore the metabolic differences in individuals and evaluate if metabolism-based patients' stratification is related to their weight loss responses to bariatric surgery. Using Self-Organizing Maps (SOMs) to analyze the plasma metabolome, we identified five distinct metabotypes, which were differentially enriched for KEGG pathways related to immune functions, fatty acid metabolism, protein-signaling, and obesity pathogenesis. The gut metagenome of the most heavily medicated metabotypes, treated simultaneously for multiple cardiometabolic comorbidities, was significantly enriched in Prevotella and Lactobacillus species. This unbiased stratification into SOM-defined metabotypes identified signatures for each metabolic phenotype and we found that the different metabotypes respond differently to bariatric surgery in terms of weight loss after 12 months. An integrative framework that utilizes SOMs and omics integration was developed for stratifying a heterogeneous bariatric surgery cohort. The multiple omics datasets described in this study reveal that the metabotypes are characterized by a concrete metabolic status and different responses in weight loss and adipose tissue reduction over time. Our study thus opens a path to enable patient stratification and hereby allow for improved clinical treatments.
Asunto(s)
Cirugía Bariátrica , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/cirugía , Obesidad/cirugía , Tejido Adiposo , AlgoritmosRESUMEN
To test the hypothesis that the gut microbiota of individuals with nonalcoholic fatty liver disease (NAFLD) produce enough ethanol to be a driving force in the development and progression of this complex disease, we performed one prospective clinical study and one intervention study. Ethanol was measured while fasting and 120 min after a mixed meal test (MMT) in 146 individuals. In a subset of 37 individuals and in an external validation cohort, ethanol was measured in portal vein blood. In an intervention study, ten individuals with NAFLD and ten overweight but otherwise healthy controls were infused with a selective alcohol dehydrogenase (ADH) inhibitor before an MMT. When compared to fasted peripheral blood, median portal vein ethanol concentrations were 187 (interquartile range (IQR), 17-516) times higher and increased with disease progression from 2.1 mM in individuals without steatosis to 8.0 mM in NAFL 21.0 mM in nonalcoholic steatohepatitis. Inhibition of ADH induced a 15-fold (IQR,1.6- to 20-fold) increase in peripheral blood ethanol concentrations in individuals with NAFLD, although this effect was abolished after antibiotic treatment. Specifically, Lactobacillaceae correlated with postprandial peripheral ethanol concentrations (Spearman's rho, 0.42; P < 10-5) in the prospective study. Our data show that the first-pass effect obscures the levels of endogenous ethanol production, suggesting that microbial ethanol could be considered in the pathogenesis of this highly prevalent liver disease.
Asunto(s)
Microbiota , Enfermedad del Hígado Graso no Alcohólico , Alcohol Deshidrogenasa , Antibacterianos , Etanol , Humanos , Hígado/patología , Enfermedad del Hígado Graso no Alcohólico/patología , Estudios ProspectivosRESUMEN
Non-alcoholic fatty liver disease (NAFLD) is now the most frequent global chronic liver disease. Individuals with NAFLD exhibited an increased risk of all-cause mortality driven by extrahepatic cancers and liver and cardiovascular disease. Once the disease is established, women have a higher risk of disease progression and worse outcome. It is therefore critical to deepen the current knowledge on the pathophysiology of NAFLD in women. Here, we used a systems biology approach to investigate the contribution of different organs to this disease. We analyzed transcriptomics profiles of liver and adipose tissues, fecal metagenomes, and plasma metabolomes of 55 women with and without NAFLD. We observed differences in metabolites, expression of human genes, and gut microbial features between the groups and revealed that there is substantial crosstalk between these different omics sets. Multi-omics analysis of individuals with NAFLD may provide novel strategies to study the pathophysiology of NAFLD in humans.
RESUMEN
Hyperglycemia and type 2 diabetes (T2D) are caused by failure of pancreatic beta cells. The role of the gut microbiota in T2D has been studied, but causal links remain enigmatic. Obese individuals with or without T2D were included from two independent Dutch cohorts. Human data were translated in vitro and in vivo by using pancreatic islets from C57BL6/J mice and by injecting flagellin into obese mice. Flagellin is part of the bacterial locomotor appendage flagellum, present in gut bacteria including Enterobacteriaceae, which we show to be more abundant in the gut of individuals with T2D. Subsequently, flagellin induces a pro-inflammatory response in pancreatic islets mediated by the Toll-like receptor (TLR)-5 expressed on resident islet macrophages. This inflammatory response is associated with beta-cell dysfunction, characterized by reduced insulin gene expression, impaired proinsulin processing and stress-induced insulin hypersecretion in vitro and in vivo in mice. We postulate that increased systemically disseminated flagellin in T2D is a contributing factor to beta-cell failure in time and represents a novel therapeutic target.
Asunto(s)
Diabetes Mellitus Tipo 2 , Flagelina , Microbioma Gastrointestinal , Células Secretoras de Insulina , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Diabetes Mellitus Tipo 2/microbiología , Flagelina/genética , Flagelina/metabolismo , Humanos , Inflamación/metabolismo , Insulina , Células Secretoras de Insulina/metabolismo , RatonesRESUMEN
Cellular senescence is an essentially irreversible growth arrest that occurs in response to various cellular stressors and may contribute to development of type 2 diabetes mellitus and nonalcoholic fatty liver disease (NAFLD). In this article, we investigated whether chronically elevated insulin levels are associated with cellular senescence in the human liver. In 107 individuals undergoing bariatric surgery, hepatic senescence markers were assessed by immunohistochemistry as well as transcriptomics. A subset of 180 participants from the ongoing Finnish Kuopio OBesity Surgery (KOBS) study was used as validation cohort. We found plasma insulin to be highly associated with various markers of cellular senescence in liver tissue. The liver transcriptome of individuals with high insulin revealed significant upregulation of several genes associated with senescence: p21, TGFß, PI3K, HLA-G, IL8, p38, Ras, and E2F. Insulin associated with hepatic senescence independently of NAFLD and plasma glucose. By using transcriptomic data from the KOBS study, we could validate the association of insulin with p21 in the liver. Our results support a potential role for hyperinsulinemia in induction of cellular senescence in the liver. These findings suggest possible benefits of lowering insulin levels in obese individuals with insulin resistance.
Asunto(s)
Diabetes Mellitus Tipo 2 , Hiperinsulinismo , Resistencia a la Insulina , Enfermedad del Hígado Graso no Alcohólico , Biomarcadores , Diabetes Mellitus Tipo 2/complicaciones , Humanos , Hiperinsulinismo/complicaciones , Insulina , Hígado , Enfermedad del Hígado Graso no Alcohólico/complicacionesRESUMEN
Obesity and type 2 diabetes (T2D) are growing burdens for individuals and the health-care system. Bariatric surgery is an efficient, but drastic treatment to reduce body weight, normalize glucose values, and reduce low-grade inflammation. The gut microbiome, which is in part controlled by intestinal antibodies, such as IgA, is involved in the development of both conditions. Knowledge of the effect of bariatric surgery on systemic and intestinal antibody response is limited. Here, we determined the fecal antibody and gut microbiome response in 40 T2D and non-diabetic (ND) obese individuals that underwent bariatric surgery (N = 40). Body weight, fasting glucose concentrations and inflammatory parameters decreased after bariatric surgery, whereas pro-inflammatory bacterial species such as lipopolysaccharide (LPS), and flagellin increased in the feces. Simultaneously, concentrations of LPS- and flagellin-specific intestinal IgA levels increased with the majority of pro-inflammatory bacteria coated with IgA after surgery. Finally, serum antibodies decreased in both groups, along with a lower inflammatory tone. We conclude that intestinal rearrangement by bariatric surgery leads to expansion of typical pro-inflammatory bacteria, which may be compensated by an improved antibody response. Although further evidence and mechanistic insights are needed, we postulate that this apparent compensatory antibody response might help to reduce systemic inflammation by neutralizing intestinal immunogenic components and thereby enhance intestinal barrier function after bariatric surgery.
Asunto(s)
Anticuerpos Antibacterianos/sangre , Bacterias/inmunología , Diabetes Mellitus Tipo 2/inmunología , Microbioma Gastrointestinal , Intestinos/microbiología , Obesidad/inmunología , Anticuerpos Antibacterianos/inmunología , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Cirugía Bariátrica , Estudios de Cohortes , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/microbiología , Diabetes Mellitus Tipo 2/cirugía , Heces/química , Heces/microbiología , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina A/inmunología , Intestinos/inmunología , Obesidad/sangre , Obesidad/microbiología , Obesidad/cirugíaRESUMEN
AIMS: Visceral adipose tissue inflammation is a fundamental mechanism of insulin resistance in obesity and type 2 diabetes. Translocation of intestinal bacteria has been suggested as a driving factor for the inflammation. However, although bacterial DNA was detected in visceral adipose tissue of humans with obesity, it is unclear to what extent this is contamination or whether the gut microbiota is causally involved. Effects of fecal microbiota transplantation (FMT) on bacterial translocation and visceral adipose tissue inflammation in individuals with obesity and insulin resistance were assessed. MATERIAL AND METHODS: Eight individuals with clinically severe obesity (body mass index [BMI] >35 kg/m2) and metabolic syndrome received lean donor FMT 4 weeks prior to elective bariatric surgery. The participants were age-, sex-, and BMI-matched to 16 controls that underwent no fecal transplantation. Visceral adipose tissue was collected during surgery. Bacterial translocation was assessed by 16S rRNA gene sequencing of adipose tissue and feces. Pro-inflammatory cytokine expression and histopathological analyses of visceral adipose tissue were performed to assess inflammation. RESULTS: Fecal microbiota transplantation significantly altered gut microbiota composition. Visceral adipose tissue contained a very low quantity of bacterial DNA in both groups. No difference in visceral bacterial DNA content between groups was observed. Also, visceral expression of pro-inflammatory cytokines and macrophage infiltration did not differ between groups. No correlation between inflammatory tone and bacterial translocation was observed. CONCLUSIONS: Visceral bacterial DNA content and level of inflammation were not altered upon FMT. Thus, bacterial translocation may not be the main driver of visceral adipose tissue inflammation in obesity.
Asunto(s)
Enzima Convertidora de Angiotensina 2/metabolismo , COVID-19 , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , SARS-CoV-2/fisiología , Serina Endopeptidasas/metabolismo , Internalización del Virus , COVID-19/metabolismo , COVID-19/virología , Perfilación de la Expresión Génica , Humanos , Unión Proteica , Glicoproteína de la Espiga del Coronavirus/metabolismo , Regulación hacia ArribaRESUMEN
The intestinal microbiota has been linked to the development and prevalence of steatohepatitis in humans. Interestingly, steatohepatitis is significantly lower in individuals taking a plant-based, low-animal-protein diet, which is thought to be mediated by gut microbiota. However, data on causality between these observations in humans is scarce. In this regard, fecal microbiota transplantation (FMT) using healthy donors is safe and is capable of changing microbial composition in human disease. We therefore performed a double-blind randomized controlled proof-of-principle study in which individuals with hepatic steatosis on ultrasound were randomized to two study arms: lean vegan donor (allogenic n = 10) or own (autologous n = 11) FMT. Both were performed three times at 8-week intervals. A liver biopsy was performed at baseline and after 24 weeks in every subject to determine histopathology (Nonalcoholic Steatohepatitis Clinical Research Network) classification and changes in hepatic gene expression based on RNA sequencing. Secondary outcome parameters were changes in intestinal microbiota composition and fasting plasma metabolomics. We observed a trend toward improved necro-inflammatory histology, and found significant changes in expression of hepatic genes involved in inflammation and lipid metabolism following allogenic FMT. Intestinal microbial community structure changed following allogenic FMT, which was associated with changes in plasma metabolites as well as markers of . Conclusion: Allogenic FMT using lean vegan donors in individuals with hepatic steatosis shows an effect on intestinal microbiota composition, which is associated with beneficial changes in plasma metabolites and markers of steatohepatitis.