Gastroenterology Report 

About: Gastroenterology Report is an academic journal. The journal publishes majorly in the area(s): Inflammatory bowel disease & Population. It has an ISSN identifier of 2304-1412. Over the lifetime, 528 publications have been published receiving 5957 citations.

Malnutrition: laboratory markers vs nutritional assessment

Abstract: Malnutrition is an independent risk factor for patient morbidity and mortality and is associated with increased healthcare-related costs. However, a major dilemma exists due to lack of a unified definition for the term. Furthermore, there are no standard methods for screening and diagnosing patients with malnutrition, leading to confusion and varying practices among physicians across the world. The role of inflammation as a risk factor for malnutrition has also been recently recognized. Historically, serum proteins such as albumin and prealbumin (PAB) have been widely used by physicians to determine patient nutritional status. However, recent focus has been on an appropriate nutrition-focused physical examination (NFPE) for diagnosing malnutrition. The current consensus is that laboratory markers are not reliable by themselves but could be used as a complement to a thorough physical examination. Future studies are needed to identify serum biomarkers in order to diagnose malnutrition unaffected by inflammatory states and have the advantage of being noninvasive and relatively cost-effective. However, a thorough NFPE has an unprecedented role in diagnosing malnutrition.

Fight Them or Feed Them: How the Intestinal Mucus Layer Manages the Gut Microbiota

Abstract: The intestinal tract is inhabited by a tremendous number of microorganisms, termed the gut microbiota. These microorganisms live in a mutualistic relationship with their host and assist in the degradation of complex carbohydrates. Although the gut microbiota is generally considered beneficial, the vast number of microbial cells also form a permanent threat to the host. Thus, the intestinal epithelium is covered with a dense layer of mucus to prevent translocation of the gut microbiota into underlying tissues. Intestinal mucus is an organized glycoprotein network with a host-specific glycan structure. While the mucus layer has long been considered a passive, host-designed barrier, recent studies showed that maturation and function of the mucus layer are strongly influenced by the gut microbiota. In return, the glycan repertoire of mucins can select for distinct mucosa-associated bacteria that are able to bind or degrade specific mucin glycans as a nutrient source. Because the intestinal mucus layer is at the crucial interface between host and microbes, its breakdown leads to gut bacterial encroachment that can eventually cause inflammation and infection. Accordingly, a dysfunctional mucus layer has been observed in colitis in mice and humans. Moreover, the increased consumption of a low-fiber Western-style diet in our modern society has recently been demonstrated to cause bacteria-mediated defects of the intestinal mucus layer. Here, I will review current knowledge on the interaction between gut bacteria and the intestinal mucus layer in health and disease. Understanding the molecular details of this host-microbe interaction may contribute to the development of novel treatment options for diseases involving a dysfunctional mucus layer, such as ulcerative colitis.

Dysbiosis of gut microbiota in promoting the development of colorectal cancer

Abstract: Gastrointestinal microbiome, containing at least 100 trillion bacteria, resides in the mucosal surface of human intestine. Recent studies show that perturbations in the microbiota may influence physiology and link to a number of diseases, including colon tumorigenesis. Colorectal cancer (CRC), the third most common cancer, is the disease resulting from multi-genes and multi-factors, but the mechanistic details between gut microenvironment and CRC remain poorly characterized. Thanks to new technologies such as metagenome sequencing, progress in large-scale analysis of the genetic and metabolic profile of gut microbial has been possible, which has facilitated studies about microbiota composition, taxonomic alterations and host interactions. Different bacterial species and their metabolites play critical roles in the development of CRC. Also, microbiota is important in the inflammatory response and immune processes deregulation during the development and progression of CRC. This review summarizes current studies regarding the association between gastrointestinal microbiota and the development of CRC, which provides insights into the therapeutic strategy of CRC.

Histological evaluation in ulcerative colitis

Abstract: This review summarizes diagnostic problems, challenges and advances in ulcerative colitis (UC). It emphasizes that, although histopathological examination plays a major role in the diagnosis and management of UC, it should always be interpreted in the context of clinical, endoscopic, and radiological findings. Accurate diagnosis requires knowledge of the classic morphological features of UC, as well as a number of atypical pathological presentations that may cause mis-classification of the disease process, either in resection or biopsy specimens. These atypical pathological presentations include rectal sparing and patchiness of disease at initial presentation of UC in pediatric patients or in the setting of medically treated UC, cecal or ascending colon inflammation in left-sided UC, and backwash ileitis in patients with severe ulcerative pancolitis. Loosely formed microgranulomas, with pale foamy histiocytes adjacent to a damaged crypt or eroded surface, should not be interpreted as evidence of Crohn’s disease. Indeterminate colitis should only be used in colectomy specimens as a provisional pathological diagnosis. Patients with UC are at risk for the development of dysplasia and carcinoma; optimal outcomes in UC surveillance programs require familiarity with the diagnostic criteria and challenges relating to UC-associated dysplasia and malignancy. Colon biopsy from UC patients should always be evaluated for dysplasia based on cytological and architectural abnormalities. Accurate interpretation and classification of dysplasia in colon biopsy from UC patients as sporadic adenoma or UC-related dysplasia [flat, adenoma-like, or dysplasia-associated lesion or mass (DALM)] requires clinical and endoscopic correlation. Isolated polypoid dysplastic lesions are considered to be sporadic adenoma if occurring outside areas of histologically proven colitis, or adenoma-like dysplasia if occurring in the diseased segment. Recent data suggest that such lesions may be treated adequately by polypectomy in the absence of flat dysplasia in the patient. UC patients with DALM or flat high-grade dysplasia should be treated by colectomy because of the high probability of adenocarcinoma. The natural history of low-grade dysplasia (LGD) is more controversial: while multifocal LGD, particularly if detected at the time of initial endoscopic examination, is treated with colectomy, unifocal flat LGD detected during surveillance may be managed by close follow-up with increased surveillance. The surveillance interval and treatment options for UC patients with dysplasia are reviewed in detail.

Colorectal polyps and polyposis syndromes

Abstract: A polyp is defined as any mass protruding into the lumen of a hollow viscus. Colorectal polyps may be classified by their macroscopic appearance as sessile (flat, arising directly from the mucosal layer) or pedunculated (extending from the mucosa through a fibrovascular stalk). Colorectal polyps may also be histologically classified as neoplastic or as non-neoplastic (hyperplastic, hamartomatous, or inflammatory). The neoplastic polyps are of primary importance because they harbor a malignant potential, which represents a stage in the development of colorectal cancer. For this reason, it is essential to identify these polyps at a sufficiently early stage, when a simple outpatient procedure to remove them can interrupt the development of colorectal cancer and prevent disease and death. When invasive carcinoma arises in a polyp, careful consideration must be given to ensuring the adequacy of treatment. Although most neoplastic polyps do not evolve into cancer, it is well accepted that the majority of colorectal carcinomas evolve from adenomatous polyps; the sequence of events leading to this transformation is referred to as the adenoma-to-carcinoma sequence. The presence of a systemic process that promotes the development of multiple gastro-intestinal polyps is termed 'polyposis'. Hereditary gastro-intestinal polyposis syndromes account for approximately 1% of all cases of colorectal cancer and are associated with a broad spectrum of extra-colonic tumors. Early detection and accurate classification of these syndromes are essential, in order to initiate a surveillance program for the early detection of cancer. Several polyposis syndromes have been described, each having its own genetic basis and characteristic polyp distribution, clinical presentation, and malignancy risk. Diagnostic modalities and treatment options for neoplastic polyps-as well as the most prevalent polyposis syndromes-are reviewed below.