The complex polymicrobial composition of human gut microbiota plays a key role in health and disease. Lachnospiraceae belong to the core of gut microbiota, colonizing the intestinal lumen from birth ...and increasing, in terms of species richness and their relative abundances during the host's life. Although, members of Lachnospiraceae are among the main producers of short-chain fatty acids, different taxa of Lachnospiraceae are also associated with different intra- and extraintestinal diseases. Their impact on the host physiology is often inconsistent across different studies. Here, we discuss changes in Lachnospiraceae abundances according to health and disease. With the aim of harnessing Lachnospiraceae to promote human health, we also analyze how nutrients from the host diet can influence their growth and how their metabolites can, in turn, influence host physiology.
Background
Initial evidence from China suggests that most vulnerable subjects to COVID‐19 infection suffer from pre‐existing illness, including metabolic abnormalities. The pandemic characteristics ...and high‐lethality rate of COVID‐19 infection have raised concerns about interactions between virus pathobiology and components of the metabolic syndrome.
Methods
We harmonized the information from the recent existing literature on COVID‐19 acute pandemic and mechanisms of damage in non‐alcoholic fatty liver disease (NAFLD), as an example of chronic (non‐communicable) metabolic pandemic.
Results
COVID‐19‐infected patients are more fragile with underlying metabolic illness, including hypertension, cardiovascular disease, type 2 diabetes, chronic lung diseases (e.g. asthma, chronic obstructive pulmonary disease and emphysema) and metabolic syndrome. During metabolic abnormalities, expansion of metabolically active fat ('overfat condition') parallels chronic inflammatory changes, development of insulin resistance and accumulation of fat in configuring NAFLD. The deleterious interplay of inflammatory pathways chronically active in NAFLD and acutely in COVID‐19‐infected patients, can explain liver damage in a subgroup of patients and might condition a worse outcome in metabolically compromised NAFLD patients. In a subgroup of patients with NAFLD, the underlying liver fibrosis might represent an additional and independent risk factor for severe COVID‐19 illness, irrespective of metabolic comorbidities.
Conclusions
NAFLD can play a role in the outcome of COVID‐19 illness due to frequent association with comorbidities. Initial evidences suggest that increased liver fibrosis in NAFLD might affect COVID‐19 outcome. In addition, long‐term monitoring of post‐COVID‐19 NAFLD patients is advisable, to document further deterioration of liver damage. Further studies are required in this field.
Nonalcoholic fatty liver disease (NAFLD) is the most frequent liver disease worldwide. Gut microbiota can play a role in the pathogenesis of NAFLD since dysbiosis is associated with reduced bacterial ...diversity, altered Firmicutes/Bacteroidetes ratio, a relative abundance of alcohol‐producing bacteria, or other specific genera. Changes can promote disrupted intestinal barrier and hyperpermeability, filtration of bacterial products, activation of the immune system, and pro‐inflammatory changes in the intestine, in the liver, and at a systemic level. Microbiota‐derived molecules can contribute to the steatogenic effects. The link between gut dysbiosis and NAFLD, however, is confused by several factors which include age, BMI, comorbidities, dietary components, and lifestyle. The role of toxic chemicals in food and water requires further studies in both gut dysbiosis and NAFLD. We can anticipate that gut microbiota manipulation will represent a potential therapeutic tool to delay or reverse the progression of NAFLD, paving the way to primary prevention measures.
Gut microbiota encompasses a wide variety of commensal microorganisms consisting of trillions of bacteria, fungi, and viruses. This microbial population coexists in symbiosis with the host, and ...related metabolites have profound effects on human health. In this respect, gut microbiota plays a pivotal role in the regulation of metabolic, endocrine, and immune functions. Bacterial metabolites include the short chain fatty acids (SCFAs) acetate (C2), propionate (C3), and butyrate (C4), which are the most abundant SCFAs in the human body and the most abundant anions in the colon. SCFAs are made from fermentation of dietary fiber and resistant starch in the gut. They modulate several metabolic pathways and are involved in obesity, insulin resistance, and type 2 diabetes. Thus, diet might influence gut microbiota composition and activity, SCFAs production, and metabolic effects. In this narrative review, we discuss the relevant research focusing on the relationship between gut microbiota, SCFAs, and glucose metabolism.
Gastric cancer constitutes one of the most prevalent malignancies in both sexes; it is currently the fourth major cause of cancer-related deaths worldwide. The pathogenesis of gastric cancer is ...associated with the interaction between genetic and environmental factors, among which infection by
(
) is of major importance. The invasion, survival, colonization, and stimulation of further inflammation within the gastric mucosa are possible due to several evasive mechanisms induced by the virulence factors that are expressed by the bacterium. The knowledge concerning the mechanisms of
pathogenicity is crucial to ameliorate eradication strategies preventing the possible induction of carcinogenesis. This review highlights the current state of knowledge and the most recent findings regarding
virulence factors and their relationship with gastric premalignant lesions and further carcinogenesis.
Bile Acid Physiology Di Ciaula, Agostino; Garruti, Gabriella; Lunardi Baccetto, Raquel ...
Annals of hepatology,
11/2017, Letnik:
16, Številka:
Suppl. 1: s3-105.
Journal Article
Recenzirano
Odprti dostop
AbstractThe primary bile acids (BAs) are synthetized from cholesterol in the liver, conjugated to glycine or taurine to increase their solubility, secreted into bile, concentrated in the gallbladder ...during fasting, and expelled in the intestine in response to dietary fat. BAs are also bio-transformed in the colon to the secondary BAs by the gut microbiota, reabsorbed in the ileum and colon back to the liver, and minimally lost in the feces. BAs in the intestine not only regulate the digestion and absorption of cholesterol, triglycerides, and fat-soluble vitamins, but also play a key role as signaling molecules in modulating epithelial cell proliferation, gene expression, and lipid and glucose metabolismby activating farnesoid X receptor (FXR) and G-protein-coupled bile acid receptor-1 (GPBAR-1, also known as TGR5) in the liver, intestine, muscle and brown adipose tissue. Recent studies have revealed the metabolic pathways of FXR and GPBAR-1 involved in the biosynthesis and enterohepatic circulation of BAs and their functions as signaling molecules on lipid and glucose metabolism.
Fecal calprotectin (FC) has been suggested as a sensitive biomarker of inflammatory bowel disease (IBD). However, its usefulness in assessing IBD activity needs to be more precisely defined. In this ...meta-analysis we aimed to determine the diagnostic performance of FC in assessing IBD endoscopic activity in adults.
We searched the databases PubMed/Medline and EMBASE, and studies which examined IBD endoscopic activity in association to FC were identified. From each study pooled data and consequently pooled sensitivity, specificity, likelihood ratios (LR), diagnostic odds ratios (DORs) and areas under the curve (AUCs) were calculated, using suitable meta-analysis software. We analyzed extracted data using fixed or random effects models, as appropriate, depending on the presence of significant heterogeneity.
We included 49 sets of data from 25 eligible for meta-analysis studies, with 298 controls and 2,822 IBD patients. Fecal calprotectin in IBD (Crohn's disease, CD and ulcerative colitis, UC) showed a pooled sensitivity of 85%, specificity of 75%, DOR of 16.3 and AUC of 0.88, in diagnosing active disease. The sub-group analysis revealed that FC performed better in UC than in CD (pooled sensitivity 87.3% vs 82.4%, specificity 77.1% vs 72.1% and AUC 0.91 vs 0.84). Examining the optimum FC cut-off levels, the best sensitivity (90.6%) was achieved at 50 μg/g, whereas the best specificity (78.2%) was found at levels >100 μg/g.
This meta-analysis showed that in adults, FC is a reliable laboratory test for assessing endoscopic activity in IBD. Its performance is better in UC than CD.
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