Microbiota inflammatory bowel disease

BACKGROUND AND AIMS: Mucoid structures that coat the epithelium play an essential role in keeping the intestinal microbiota at a safe distance from host cells. Encroachment of bacteria into the normally almost-sterile inner mucus layer has been observed in inflammatory bowel disease and in mouse models of colitis. Moreover, such microbiota encroachment has also been observed in mouse models of metabolic syndrome, which are associated low-grade intestinal inflammation. Hence, we investigated if microbiota encroachment might correlate with indices of metabolic syndrome in humans...

BACKGROUND: Increased delivery of taurine-conjugated bile acids to the distal bowel can lead to dysbiosis resulting in colitis in mouse models of inflammatory bowel disease. A similar situation also could occur in cats with intestinal disease and might therefore result in decreased whole-body taurine concentration. HYPOTHESIS/OBJECTIVES: To determine whether whole-blood taurine concentrations are decreased at the time of diagnosis in cats with intestinal disease and to correlate concentrations with clinical and laboratory variables...

The composition of the intestinal microbiota varies among individuals and throughout development, and is dependent on host and environmental factors. However, although the microbiota is constantly exposed to environmental challenges, its composition and function in an individual are stable against perturbations, as microbial communities are resilient and resistant to change. The maintenance of a beneficial microbiota requires a homeostatic equilibrium within microbial communities, and also between the microorganisms and the intestinal interface of the host...

The human gastrointestinal tract is populated by a diverse, highly mutualistic microbial flora, which is known as the microbiome. Disruptions to the microbiome have been shown to be associated with severe pathologies of the host, including metabolic disease, cancer, and inflammatory bowel disease. Mood and behavior are also susceptible to alterations in the gut microbiota. A particularly striking example of the symbiotic effects of the microbiome is the immune system, whose cells depend critically on a diverse array of microbial metabolites for normal development and behavior...

Objective HLA-B27 associated spondyloarthropathies are associated with an altered intestinal microbiota and bowel inflammation. Therefore, we sought to identify B27-dependent changes in both host and microbial metabolites in the HLA-B27/β2m rat and whether microbiota-derived metabolites could impact disease in this major model of spondyloarthropathy. Methods Cecal contents were collected from 6wk (pre-diseased) and 16wk (diseased) Fischer 344 HLA-B27/β2m transgenic rats and WT controls. Metabolomic profiling was performed by high-throughput gas- and liquid-chromatography-based mass spectrometry...

Crohn's disease (CD) is a chronic, non-specific granulomatous inflammatory disorder that commonly affects the small intestine and is a phenotype of inflammatory bowel disease (IBD). CD is prone to relapse, and its incidence displays a persistent increase in developing countries. However, the pathogenesis of CD is poorly understood, with some studies emphasizing the link between CD and the intestinal microbiota. Specifically, studies point to the brain-gut-enteric microbiota axis as a key player in the occurrence and development of CD...

The history of fecal microbiota transplantation (FMT) dates back even to ancient China. Recently, scientific studies have been looking into FMT as a promising treatment of various diseases, while in the process teaching us about the interaction between the human host and its resident microbial communities. Current research focuses mainly on Clostridium difficile infections, however interest is rising in other areas such as inflammatory bowel disease (IBD) and the metabolic syndrome. With regard to the latter, the intestinal microbiota might be causally related to the progression of insulin resistance and diabetes...

Inflammatory bowel disease (IBD) is a complex set of diseases that lead to chronic inflammation in the gastrointestinal tract. Although the etiology of IBD is not fully understood, it is well-known that the intestinal microbiota is associated with the development and maintenance of IBD. Manipulation of the gut microbiota, therefore, may represent a target for IBD therapy. Fecal microbiota transplantation (FMT), where fecal microbiota from a healthy donor is transplanted into a patient's GI tract, is already a successful therapy for Clostridium difficile infection...

OBJECTIVE: Altered microbiota composition or dysbiosis is suspected to be implicated in the pathogenesis of chronic inflammatory diseases, such as spondyloarthritis (SpA) and rheumatoid arthritis (RA). METHODS: 16S ribosomal RNA gene sequencing was performed on faecal DNA isolated from stool samples in two consecutive cross-sectional cohorts, each comprising three groups of adult volunteers: SpA, RA and healthy controls (HCs). In the second study, HCs comprised a majority of aged-matched siblings of patients with known HLA-B27 status...

Bile acids are synthesized from cholesterol in the liver and released into the intestine to aid the digestion of dietary lipids. The host enzymes that contribute to bile acid synthesis in the liver and the regulatory pathways that influence the composition of the total bile acid pool in the host have been well established. In addition, the gut microbiota provides unique contributions to the diversity of bile acids in the bile acid pool. Gut microbial enzymes contribute significantly to bile acid metabolism through deconjugation and dehydroxylation reactions to generate unconjugated bile acids and secondary bile acids...

BACKGROUND: Trimethylamine-N-oxide (TMAO) is produced in the liver from trimethylamine, which is exclusively generated by gut bacteria. OBJECTIVE: The objective of this article is to investigate the relationship between TMAO and primary sclerosing cholangitis (PSC) and its clinical characteristics. METHODS: Serum TMAO was measured in 305 PSC patients, 90 ulcerative colitis patients and 99 healthy controls. RESULTS: In PSC patients with normal liver function (n = 197), TMAO was higher in patients reaching liver transplantation or death during follow-up than those who did not, with an optimal TMAO cut-off of 4...

The intestine is home to trillions of microorganisms, and the vast diversity within this gut microbiota exists in a balanced state to protect the intestinal mucosal barrier. Research into the association of the intestinal microbiota with health and disease (including diet, nutrition, obesity, inflammatory bowel disease, and cancer) continues to expand, with the field advancing at a rapid rate. Intestinal stem cells (ISCs) are the fundamental component of the mucosal barrier; they undergo continuous proliferation to replace the epithelium, which is also intimately involved in intestinal diseases...

Background: The intestinal microbiota, through complex interactions with the gut mucosa, play a key role in the pathogenesis of colon carcinoma and inflammatory bowel disease (IBD). The disease condition and dietary habits both influence gut microbial diversity. Objective: The aim of this study was to assess the gut microbial profile of healthy subjects and patients with colon carcinoma and IBD. Healthy subjects included 'Indian vegetarians/lactovegetarians', who eat plant produce, milk and milk products, and 'Indian non-vegetarians', who eat plant produce, milk and milk products, certain meats and fish, and the eggs of certain birds and fish...

Background: The availability of fresh stool samples is a prerequisite in most gut microbiota functional studies. Objective: Strategies for amplification and long-term gut microbiota preservation from fecal samples would favor sample sharing, help comparisons and reproducibility over time and between laboratories, and improve the safety and ethical issues surrounding fecal microbiota transplantations. Design: Taking advantage of in vitro gut-simulating systems, we amplified the microbial repertoire of a fresh fecal sample and assessed the viability and resuscitation of microbes after preservation with some common intracellular and extracellular acting cryoprotective agents (CPAs), alone and in different combinations...

The intestinal epithelium can be easily disrupted during gut inflammation as seen in inflammatory bowel disease (IBD), such as ulcerative colitis or Crohn's disease. For a long time, research into the pathophysiology of IBD has been focused on immune cell-mediated mechanisms. Recent evidence, however, suggests that the intestinal epithelium might play a major role in the development and perpetuation of IBD. It is now clear that IBD can be triggered by disturbances in epithelial barrier integrity via dysfunctions in intestinal epithelial cell-intrinsic molecular circuits that control the homeostasis, renewal, and repair of intestinal epithelial cells...

It has become increasingly evident over the past two decades that the microbiota plays a nurturing role in the development of the immune system. This appears to be important since the amplitude of immune responses has a crucial regulatory function in homeostasis and the prevention of unwanted inflammation. Hence, a malfunctioning gut flora has been shown to play a key role in visceral medicine. Strong evidence demonstrates for example that intestinal inflammation can develop as a result of a dysregulated microbiota, deficient antimicrobial responses, and aberrant bacterial translocation into the bowel wall...

It is estimated that 1.4 million people in the United States suffer from Inflammatory Bowel Disease (IBD), with an overall annual health care cost of more than $1.7 billion. Although the exact etiology of this disease remains unknown, research suggests that it is a multifactorial disease associated with aberrant gastrointestinal microbial populations (dysbiosis). The C57BL/6 and C3H/HeJBir mouse strains with targeted mutations in the IL-10 gene are commonly used models to study IBD. However, anecdotally, disease phenotype can vary in severity from lab to lab...

BACKGROUND & AIMS: Intestinal epithelial homeostasis is maintained by complex interactions among epithelial cells, commensal gut microorganisms, and immune cells. Disruption of this homeostasis is associated with disorders such as inflammatory bowel disease, but the mechanisms of this process are not clear. We investigated how Sirtuin 1 (SIRT1), a conserved mammalian NAD(+)-dependent protein deacetylase, senses environmental stress to alter intestinal integrity. METHODS: We performed studies of mice with disruption of Sirt1 specifically in the intestinal epithelium (SIRT1 iKO, villin-Cre+, Sirt1(flox/flox) mice) and control mice (villin-Cre-, Sirt1(flox/flox)) on a C57BL/6 background...

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract caused by a dysregulated immune response to the fecal microbiota. Very early-onset inflammatory bowel disease (VEO-IBD) refers to a subgroup of pediatric patients with IBD diagnosed before 6 years of age. This subgroup is often characterized by increased severity, aggressive progression, strong family history of IBD, and often poor response to conventional treatments. Nutritional therapies have been utilized to treat IBD, but their role in VEO-IBD is unclear...

Fecal microbiota transplantation (FMT) has evolved from a case report in the medical literature to the basis of major innovations in the treatment of Clostridium difficile infection (CDI) and, potentially, inflammatory bowel disease (IBD). In the clinical setting, FMT was noted to significantly lower the risk of recurrent CDI, likely by increasing microbial diversity and altering the metabolic environment in the intestinal tract of recipients. In parallel, advances in the ability to quantify and characterize microbial communities in fecal samples led to the association of IBD with a state of intestinal dysbiosis...