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Science (New York, N.Y.) Jul 2022Changes in the composition of the gut microbiota are associated with many human diseases. So far, however, we have failed to define homeostasis or dysbiosis by the... (Review)
Review
Changes in the composition of the gut microbiota are associated with many human diseases. So far, however, we have failed to define homeostasis or dysbiosis by the presence or absence of specific microbial species. The composition and function of the adult gut microbiota is governed by diet and host factors that regulate and direct microbial growth. The host delivers oxygen and nitrate to the lumen of the small intestine, which selects for bacteria that use respiration for energy production. In the colon, by contrast, the host limits the availability of oxygen and nitrate, which results in a bacterial community that specializes in fermentation for growth. Although diet influences microbiota composition, a poor diet weakens host control mechanisms that regulate the microbiota. Hence, quantifying host parameters that control microbial growth could help define homeostasis or dysbiosis and could offer alternative strategies to remediate dysbiosis.
Topics: Bacteria; Colon; Dysbiosis; Gastrointestinal Microbiome; Homeostasis; Host Microbial Interactions; Humans; Intestine, Small; Nitrates; Oxygen
PubMed: 35771903
DOI: 10.1126/science.abp9960 -
JNMA; Journal of the Nepal Medical... Apr 2023Adhesion is a leading cause of small bowel obstruction. Adhesive small bowel obstruction has significant challenges in diagnosis, treatment and prevention with... (Review)
Review
UNLABELLED
Adhesion is a leading cause of small bowel obstruction. Adhesive small bowel obstruction has significant challenges in diagnosis, treatment and prevention with considerable impact on morbidity and socioeconomic burden. Small bowel obstruction caused by adhesion or any other aetiology is clinically indistinguishable due to similar clinical presentation. Computed Tomography scans and water-soluble contrast studies are more specific in diagnosis and possess value in predicting the need for surgery. Surgical management is indicated only in complicated cases or failed conservative treatments with the majority resolving with non-operative management. However, there is no clear-cut consensus about the timing of operative intervention. Meticulous surgical practice is the keystone in preventing adhesion formation despite the availability of numerous pharmacological and surgical strategies. This review aims to update the current knowledge of the pathophysiology of adhesion formation, treatment options and various prevention modalities of adhesive small bowel obstruction.
KEYWORDS
diagnosis; laparotomy; prevention; surgery.
Topics: Humans; Intestinal Obstruction; Tissue Adhesions; Contrast Media; Intestine, Small; Conservative Treatment
PubMed: 37208871
DOI: 10.31729/jnma.8134 -
International Journal of Molecular... Oct 2021Intestinal epithelial cells (IECs) are crucial for the digestive process and nutrient absorption. The intestinal epithelium is composed of the different cell types of... (Review)
Review
Intestinal epithelial cells (IECs) are crucial for the digestive process and nutrient absorption. The intestinal epithelium is composed of the different cell types of the small intestine (mainly, enterocytes, goblet cells, Paneth cells, enteroendocrine cells, and tuft cells). The small intestine is characterized by the presence of crypt-villus units that are in a state of homeostatic cell turnover. Organoid technology enables an efficient expansion of intestinal epithelial tissue in vitro. Thus, organoids hold great promise for use in medical research and in the development of new treatments. At present, the cholinergic system involved in IECs and intestinal stem cells (ISCs) are attracting a great deal of attention. Thus, understanding the biological processes triggered by epithelial cholinergic activation by acetylcholine (ACh), which is produced and released from neuronal and/or non-neuronal tissue, is of key importance. Cholinergic signaling via ACh receptors plays a pivotal role in IEC growth and differentiation. Here, we discuss current views on neuronal innervation and non-neuronal control of the small intestinal crypts and their impact on ISC proliferation, differentiation, and maintenance. Since technology using intestinal organoid culture systems is advancing, we also outline an organoid-based organ replacement approach for intestinal diseases.
Topics: Acetylcholine; Animals; Cell Culture Techniques; Cell Differentiation; Cell Proliferation; Intestinal Mucosa; Intestine, Small; Models, Biological; Organoids; Receptors, Cholinergic; Stem Cells
PubMed: 34681571
DOI: 10.3390/ijms222010912 -
International Journal of Molecular... May 2020Small intestinal bacterial overgrowth (SIBO) is a condition hallmarked by an increase in the concentration of colonic-type bacteria in the small bowel. Watery diarrhea,... (Review)
Review
Small intestinal bacterial overgrowth (SIBO) is a condition hallmarked by an increase in the concentration of colonic-type bacteria in the small bowel. Watery diarrhea, bloating, abdominal pain and distension are the most common clinical manifestations. Additionally, malnutrition and vitamin (B12, D, A, and E) as well as minerals (iron and calcium) deficiency may be present. SIBO may mask or worsen the history of some diseases (celiac disease, irritable bowel disease), may be more common in some extra-intestinal disorders (scleroderma, obesity), or could even represent a pathogenetic link with some diseases, in which a perturbation of intestinal microbiota may be involved. On these bases, we performed a review to explore the multiple links between SIBO and digestive and extra-intestinal diseases.
Topics: Animals; Blind Loop Syndrome; Disease; Humans; Intestine, Small
PubMed: 32429454
DOI: 10.3390/ijms21103531 -
Gut Microbes 2021Mucin-degrading bacteria are densely populated in the intestinal epithelium; however, their interaction with intestinal stem cells (ISCs) and their progeny have not been...
Mucin-degrading bacteria are densely populated in the intestinal epithelium; however, their interaction with intestinal stem cells (ISCs) and their progeny have not been elucidated. To determine whether mucin-degrading bacteria play a role in gut homeostasis, mice were treated with , a specialized species that degrades mucin. Administration of for 4 weeks accelerated the proliferation of Lgr5 ISCs and promoted the differentiation of Paneth cells and goblet cells in the small intestine (SI). We found similar effects of in the colon. The levels of acetic and propionic acids were higher in the cecal contents of -treated mice than in PBS-treated mice. SI organoids treated with cecal contents obtained from -treated mice were larger and could be diminished by treatment with G protein-coupled receptor (Gpr) 41/43 antagonists. Pre-treatment of mice with reduced gut damage caused by radiation and methotrexate. Further, a novel isotype of the strain was isolated from heathy human feces that showed enhanced function in intestinal epithelial regeneration. These findings suggest that mucin-degrading bacteria (e.g., ) may play a crucial role in promoting ISC-mediated epithelial development and contribute to intestinal homeostasis maintenance.
Topics: Akkermansia; Animals; Cell Differentiation; Cell Proliferation; Epithelial Cells; Fatty Acids, Volatile; Feces; Female; Gastrointestinal Microbiome; Homeostasis; Humans; Intestinal Mucosa; Intestine, Small; Methotrexate; Mice; Mice, Inbred C57BL; Mucins; Stem Cells; Wnt Signaling Pathway
PubMed: 33678130
DOI: 10.1080/19490976.2021.1892441 -
Annals of the Royal College of Surgeons... Oct 2020Intertwining of bowel loops to form a knot is very rare cause of intestinal obstruction. Among intestinal knots, ileoileal knotting is the most rare, with only a handful... (Review)
Review
INTRODUCTION
Intertwining of bowel loops to form a knot is very rare cause of intestinal obstruction. Among intestinal knots, ileoileal knotting is the most rare, with only a handful of cases reported in literature. We present a rare case of ileoileal knotting and review of small bowel knots. The aim of this review was to summarise the existing evidence on small bowel knots and to postulate the possible mechanisms for knotting.
METHODS
A systematic search was conducted for literature published up to December 2019 using MEDLINE, PubMed and Google Scholar databases, together with the references of the full-text articles retrieved. Papers with case reports of small bowel knots were considered to be eligible for inclusion in the review.
FINDINGS
A total of 14 case reports were evaluated. There was no clear predilection for age or sex. Mostly cases were from Asia and Africa with no cases from the West. The presenting complaints were abdominal pain (93%), vomiting (64%), abdominal distention (57 %) and obstipation (43%). The bowel was gangrenous in 78% of cases. All underwent exploration, with the majority requiring resection and anastomosis of the involved segment.
CONCLUSION
Ileoileal knotting is a very rare cause of intestinal obstruction. Possible mechanisms include loaded bowel with longer mesentery, vigorous peristalsis, single bulky meal, pregnancy and intussusception. The condition is extremely difficult to diagnose preoperatively and it is usually diagnosed intraoperatively. The standard of treatment is resection of gangrenous part and anastomosis.
Topics: Abdominal Pain; Adult; Aged; Aged, 80 and over; Female; Gangrene; Humans; Infant; Intestinal Obstruction; Intestinal Volvulus; Intestine, Small; Intussusception; Male; Middle Aged; Vomiting; Young Adult
PubMed: 32538120
DOI: 10.1308/rcsann.2020.0122 -
Current Gastroenterology Reports Jan 2020Probiotics are promising remedial treatments for symptoms of small intestine (SI) diseases and promoters of overall good health. Probiotics play an important role in... (Review)
Review
PURPOSE OF REVIEW
Probiotics are promising remedial treatments for symptoms of small intestine (SI) diseases and promoters of overall good health. Probiotics play an important role in supporting a healthy SI microbiome (eubiosis), and in preventing establishment of unhealthy microbiota. SI eubiosis promotes optimal nutrient uptake, and optimal nutritional status maintains a healthy SI, reducing the likelihood of SI diseases. It is important to understand the advantages and limitations of probiotic therapies.
RECENT FINDINGS
Microbial dysbiosis decreases the capacity of the small bowel to utilize and absorb dietary compounds. In some studies, probiotic supplements containing lactic acid bacteria and Bifidobacterium have been demonstrated effective in supporting beneficial microbes in the SI while improving barrier integrity and reducing nutrient malabsorption and SI disease-related pathology. Strain-specific probiotic therapy may be a natural and effective approach to restoring SI barrier integrity and eubiosis, resulting in improved nutrient absorption and better health, including reducing the incidence of and severity of SI diseases.
Topics: Cell Membrane Permeability; Diet; Dysbiosis; Gastrointestinal Microbiome; Humans; Intestinal Diseases; Intestine, Small; Nutritional Status; Probiotics
PubMed: 31930437
DOI: 10.1007/s11894-019-0740-3 -
Tidsskrift For Den Norske Laegeforening... May 2023Paraduodenal hernia is a rare form of congenital internal hernia and can lead to small bowel obstruction. This case report describes the case of a young boy who was...
Paraduodenal hernia is a rare form of congenital internal hernia and can lead to small bowel obstruction. This case report describes the case of a young boy who was admitted with acute exacerbation of chronic abdominal pain.
Topics: Male; Humans; Hernia; Paraduodenal Hernia; Duodenal Diseases; Intestine, Small; Intestinal Obstruction
PubMed: 37254989
DOI: 10.4045/tidsskr.22.0506 -
Best Practice & Research. Clinical... 2023Small-bowel (SB) bleeding is a challenging problem for the clinician, presenting many pitfalls in both diagnosis and subsequent treatment. Videocapsule endoscopy (VCE)... (Review)
Review
Small-bowel (SB) bleeding is a challenging problem for the clinician, presenting many pitfalls in both diagnosis and subsequent treatment. Videocapsule endoscopy (VCE) and device-assisted enteroscopy (DAE) have revolutionized the approach to the patient with SB bleeding, allowing for the endoscopic diagnosis and management of what was previously only a surgical matter. The patients' assessment in SB bleeding is of foremost importance, as treatment success relies on a detailed evaluation of clinical history, suspicion for underlying lesions, and a careful selection and timing of diagnostic and therapeutic tools. This review will summarize current state-of-the-art evidence and practice points, to provide the clinician with a comprehensive guide towards the management of SB bleeding.
Topics: Humans; Intestine, Small; Capsule Endoscopy; Gastrointestinal Hemorrhage; Laparoscopy
PubMed: 37652647
DOI: 10.1016/j.bpg.2023.101844 -
Clinical Radiology Aug 2019Magnetic resonance imaging (MRI)-based techniques have emerged as the preferred technique for the diagnostic evaluation of the small intestine, particularly in the adult... (Review)
Review
Magnetic resonance imaging (MRI)-based techniques have emerged as the preferred technique for the diagnostic evaluation of the small intestine, particularly in the adult population. The lack of ionising radiation makes MRI ideal for use in younger patients or in cases that require repeated follow-up investigations. Imaging of the small intestine may be carried out using the intubation (enteroclysis) or the ingestion (enterography) techniques. Enterography examinations are more acceptable to patients and may provide similar diagnostic accuracy compared to intubation methods. In this review, methods of improving and optimising MRI of the small intestine are described.
Topics: Humans; Inflammatory Bowel Diseases; Intestine, Small; Magnetic Resonance Imaging
PubMed: 30967243
DOI: 10.1016/j.crad.2019.03.007