The gastrointestinal tract is a complex and dynamic network where an intricate and mutualistic symbiosis modulates the relationship between the host and the microbiota in order to establish and ...ensure gut homeostasis. Commensal Clostridia consist of gram-positive, rod-shaped bacteria in the phylum Firmicutes and make up a substantial part of the total bacteria in the gut microbiota. They start to colonize the intestine of breastfed infants during the first month of life and populate a specific region in the intestinal mucosa in close relationship with intestinal cells. This position allows them to participate as crucial factors in modulating physiologic, metabolic and immune processes in the gut during the entire lifespan, by interacting with the other resident microbe populations, but also by providing specific and essential functions. This review focus on what is currently known regarding the role of commensal Clostridia in the maintenance of overall gut function, as well as touch on their potential contribution in the unfavorable alteration of microbiota composition (dysbiosis) that has been implicated in several gastrointestinal disorders. Commensal Clostridia are strongly involved in the maintenance of overall gut function. This leads to important translational implications in regard to the prevention and treatment of dysbiosis, to drug efficacy and toxicity, and to the development of therapies that may modulate the composition of the microflora, capitalizing on the key role of commensal Clostridia, with the end goal of promoting gut health.
Diet and nutrition are known to play key roles in many chronic gastrointestinal diseases, regarding both pathogenesis and therapeutic possibilities. A strong correlation between symptomatology, ...disease activity and eating habits has been observed in many common diseases, both organic and functional, such as inflammatory bowel disease and irritable bowel syndrome. New different dietary approaches have been evaluated in order improve patients' symptoms, modulating the type of sugars ingested, the daily amount of fats or the kind of metabolites produced in gut. Even if many clinical studies have been conducted to fully understand the impact of nutrition on the progression of disease, more studies are needed to test the most promising approaches for different diseases, in order to define useful guidelines for patients.
The gut microbiota is involved in the maintenance of the homeostasis of the human body and its alterations are associated with the development of different pathological conditions. The liver is the ...organ most exposed to the influence of the gut microbiota, and recently important connections between the intestinal flora and hepatocellular carcinoma (HCC) have been described. In fact, HCC is commonly associated with liver cirrhosis and develops in a microenvironment where inflammation, immunological alterations, and cellular aberrations are dramatically evident. Prevention and diagnosis in the earliest stages are still the most effective weapons in fighting this tumor. Animal models show that the gut microbiota can be involved in the promotion and progression of HCC directly or through different pathogenic mechanisms. Recent data in humans have confirmed these preclinical findings, shedding new light on HCC pathogenesis. Limitations due to the different experimental design, the ethnic and hepatological setting make it difficult to compare the results and draw definitive conclusions, but these studies lay the foundations for a pathogenetic redefinition of HCC. Therefore, it is evident that the characterization of the gut microbiota and its modulation can have an enormous diagnostic, preventive, and therapeutic potential, especially in patients with early stage HCC.
The intestinal barrier, with its multiple layers, is the first line of defense between the outside world and the intestine. Its disruption, resulting in increased intestinal permeability, is a ...recognized pathogenic factor of intestinal and extra-intestinal diseases. The identification of a gut-vascular barrier (GVB), consisting of a structured endothelium below the epithelial layer, has led to new evidence on the etiology and management of diseases of the gut-liver axis and the gut-brain axis, with recent implications in oncology as well. The gut-brain axis is involved in several neuroinflammatory processes. In particular, the recent description of a choroid plexus vascular barrier regulating brain permeability under conditions of gut inflammation identifies the endothelium as a key regulator in maintaining tissue homeostasis and health.
The discovery of Helicobacter pylori infection in the stomach could be considered as one of the most important events of modern gastroenterology. Understanding of the natural history of many ...disorders of the upper gastrointestinal tract, including chronic gastritis, peptic ulcer disease, gastric cancer and MALT lymphoma, was altered by this discovery. Interestingly, epidemiological studies have also revealed a correlation between H. pylori infection and some diseases localized outside the stomach, especially those characterized by persistent and low-grade systemic inflammation. Of note, H. pylori has an important role in iron deficiency anaemia, idiopathic thrombocytopenic purpura and vitamin B12 deficiency. Moreover, the association of this bacterial pathogen with many other diseases, including hepatobiliary, pancreatic, cardiovascular and neurodegenerative disorders is currently under investigation. In this Review, we summarize the results of the most important studies performed to date surrounding the association of H. pylori infection with extragastric diseases, as well as the strength of the evidence. We also provide information concerning bacterial-host interactions and the mechanisms implicated in the pathogenesis of each of these extragastric diseases.
Background
A remarkably high incidence of venous thromboembolism (VTE) has been reported among critically ill patients with COVID‐19 assisted in the intensive care unit (ICU). However, VTE burden ...among non‐ICU patients hospitalized for COVID‐19 that receive guideline‐recommended thromboprophylaxis is unknown.
Objectives
To determine the incidence of VTE among non‐ICU patients hospitalized for COVID‐19 that receive pharmacological thromboprophylaxis.
Methods
We performed a systematic screening for the diagnosis of deep vein thrombosis (DVT) by lower limb vein compression ultrasonography (CUS) in consecutive non‐ICU patients hospitalized for COVID‐19, independent of the presence of signs or symptoms of DVT. All patients were receiving pharmacological thromboprophylaxis with either enoxaparin or fondaparinux.
Results
The population that we screened consisted of 84 consecutive patients, with a mean age of 67.6 ± 13.5 years and a mean Padua Prediction Score of 5.1 ± 1.6. Seventy‐two patients (85.7%) had respiratory insufficiency, required oxygen supplementation, and had reduced mobility or were bedridden. In this cohort, we found 10 cases of DVT, with an incidence of 11.9% (95% confidence interval CI 4.98‐18.82). Of these, 2 were proximal DVT (incidence rate 2.4%, 95% CI −0.87‐5.67) and 8 were distal DVT (incidence rate 9.5%, 95% CI 3.23‐5.77). Significant differences between subjects with and without DVT were D‐dimer > 3000 µg/L (P < .05), current or previous cancer (P < .05), and need of high flow nasal oxygen therapy and/or non‐invasive ventilation (P < .01).
Conclusions
DVT may occur among non‐ICU patients hospitalized for COVID‐19, despite guideline‐recommended thromboprophylaxis.
Hormonal changes during and after pregnancy are linked with modifications in the maternal microbiota. We describe the importance of the maternal microbiota in pregnancy and examine whether changes in ...maternal microbiotic composition at different body sites (gut, vagina, endometrium) are associated with pregnancy complications. We analyze the likely interactions between microbiota and the immune system. During pregnancy, the gastrointestinal (gut) microbiota undergoes profound changes that lead to an increase in lactic acid-producing bacteria and a reduction in butyrate-producing bacteria. The meaning of such changes needs clarification. Additionally, several studies have indicated a possible involvement of the maternal gut microbiota in autoimmune and lifelong diseases. The human vagina has its own microbiota, and changes in vaginal microbiota are related to several pregnancy-related complications. Recent studies show reduced lactobacilli, increased bacterial diversity, and low vaginal levels of beta-defensin 2 in women with preterm births. In contrast, early and healthy pregnancies are characterized by low diversity and low numbers of bacterial communities dominated by
. These observations suggest that early vaginal cultures that show an absence of
and polymicrobial vaginal colonization are risk factors for preterm birth. The endometrium is not a sterile site. Resident endometrial microbiota has only been defined recently. However, questions remain regarding the main components of the endometrial microbiota and their impact on the reproductive tract concerning both fertility and pregnancy outcomes. A classification based on endometrial bacterial patterns could help develop a microbiota-based diagnosis as well as personalized therapies for the prevention of obstetric complications and personalized treatments through nutritional, microbiotic, or pharmaceutical interventions.
Digestive enzymes are able to break down proteins and carbohydrates and lipids, and their supplementation may play a role in the management of digestive disorders, from lactose intolerance to cystic ...fibrosis. To date, several formulations of digestive enzymes are available on the market, being different each other in terms of enzyme type, source and origin, and dosage.
This review, performed through a non-systematic search of the available literature, will provide an overview of the current knowledge of digestive enzyme supplementation in gastrointestinal disorders, discussion of the use of pancreatic enzymes, lactase (β-galactosidase) and conjugated bile acids, and also exploring the future perspective of digestive enzyme supplementation.
Currently, the animal-derived enzymes represent an established standard of care, however the growing study of plant-based and microbe-derived enzymes offers great promise in the advancement of digestive enzyme therapy.
New frontiers of enzyme replacement are being evaluated also in the treatment of diseases not specifically related to enzyme deficiency, whereas the combination of different enzymes might constitute an intriguing therapeutic option in the future.
Bacteriocins are bactericidal peptides, ribosomally synthesized, with an inhibitory activity against diverse groups of undesirable microorganisms. Bacteriocins are produced by both gram-positive and ...gram-negative bacteria, and to a lesser extent by some archaea. Bacteriophages are viruses that are able to infect bacterial cells and force them to produce viral components, using a lytic or lysogenic cycle. They constitute a large community in the human gut called the phageome, the most abundant part of the gut virome. Bacteriocins and bacteriophages may have an influence on both human health and diseases, thanks to their ability to modulate the gut microbiota and regulate the competitive relationship among the different microorganisms, strains and cells living in the human intestine. In this review, we explore the role of bacteriocins and bacteriophages in the most frequent gastrointestinal diseases by dissecting their interaction with the complex environment of the human gut, analyzing a possible link with extra-intestinal diseases, and speculating on their possible therapeutic application with the end goal of promoting gut health.
Autism spectrum disorder (ASD) is a complex behavioral syndrome that is characterized by speech and language disorders, intellectual impairment, learning and motor dysfunctions. Several genetic and ...environmental factors are suspected to affect the ASD phenotype including air pollution, exposure to pesticides, maternal infections, inflammatory conditions, dietary factors or consumption of antibiotics during pregnancy. Many children with ASD shows abnormalities in gastrointestinal (GI) physiology, including increased intestinal permeability, overall microbiota alterations, and gut infection. Moreover, they are "picky eaters" and the existence of specific sensory patterns in ASD patients could represent one of the main aspects in hampering feeding. GI disorders are associated with an altered composition of the gut microbiota. Gut microbiome is able to communicate with brain activities through microbiota-derived signaling molecules, immune mediators, gut hormones as well as vagal and spinal afferent neurons. Since the diet induces changes in the intestinal microbiota and in the production of molecules, such as the SCFA, we wanted to investigate the role that nutritional intervention can have on GI microbiota composition and thus on its influence on behavior, GI symptoms and microbiota composition and report which are the beneficial effect on ASD conditions.
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