intestinal tract
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Author(s):  
Tammy J. Barnaba ◽  
Jayanthi Gangiredla ◽  
Mark K. Mammel ◽  
David W. Lacher ◽  
Carmen Tartera

We present the genome sequences of nine Bacillus isolates and two Weizmannia isolates from 10 different dietary supplements and one cultured food product. Strains of these species have been associated with health benefits when ingested by humans, due to their ability to survive the stomach’s acidic environment and colonize the intestinal tract.


2022 ◽  
Vol 119 (3) ◽  
pp. e2115230119
Author(s):  
Mariko Kamioka ◽  
Yoshiyuki Goto ◽  
Kiminori Nakamura ◽  
Yuki Yokoi ◽  
Rina Sugimoto ◽  
...  

Paneth cells are intestinal epithelial cells that release antimicrobial peptides, such as α-defensin as part of host defense. Together with mesenchymal cells, Paneth cells provide niche factors for epithelial stem cell homeostasis. Here, we report two subtypes of murine Paneth cells, differentiated by their production and utilization of fucosyltransferase 2 (Fut2), which regulates α(1,2)fucosylation to create cohabitation niches for commensal bacteria and prevent invasion of the intestine by pathogenic bacteria. The majority of Fut2− Paneth cells were localized in the duodenum, whereas the majority of Fut2+ Paneth cells were in the ileum. Fut2+ Paneth cells showed higher granularity and structural complexity than did Fut2− Paneth cells, suggesting that Fut2+ Paneth cells are involved in host defense. Signaling by the commensal bacteria, together with interleukin 22 (IL-22), induced the development of Fut2+ Paneth cells. IL-22 was found to affect the α-defensin secretion system via modulation of Fut2 expression, and IL-17a was found to increase the production of α-defensin in the intestinal tract. Thus, these intestinal cytokines regulate the development and function of Fut2+ Paneth cells as part of gut defense.


2022 ◽  
Vol 2022 ◽  
pp. 1-7
Author(s):  
Tian-Ming Li ◽  
Dong-Yan Liu

High concentration oxygen is widely used in the treatment of neonates, which has a significant effect on improving blood oxygen concentration in neonates with respiratory distress. The adverse effects of hyperoxia therapy on the lung, retina, and neurodevelopment of newborns have been extensively studied, but less attention has been paid to intestinal damage caused by hyperoxia therapy. In this review, we focus on the physical, immune, and microorganism barriers of the intestinal tract and discuss neonatal intestinal tract damage caused by hyperoxia therapy and analyze the molecular mechanism of intestinal damage caused by hyperoxia in combination with necrotizing enterocolitis.


Author(s):  
Aoi Koga ◽  
Takumi Yamasaki ◽  
Shuhei Hayashi ◽  
Shinjiro Yamamoto ◽  
Hitoshi Miyasaka

Abstract Purple non-sulfur bacteria (PNSB) reportedly have probiotic effects in fish, but whether they are indigenous in the digestive tract of fish is a question that requires answering. We attempted to isolate PNSB from the digestive tract of ayu (Plecoglossus altivelis) from the Kuma River (Kumamoto, Japan), and successfully isolated 12 PNSB strains. All the isolated PNSB belonged to the genus Rhodopseudomonas. Five Rhodopseudomonas strains were also isolated from the soil samples collected along the Kuma River. The phylogenetic tree based on the partial sequence of pufLM gene indicated that the PNSB from ayu and soil were similar. The effects of NaCl concentration in growth medium on growth were also compared between the PNSB from ayu and soil. The PNSB from ayu showed a better growth performance at a higher NaCl concentration, suggesting that the intestinal tract of ayu, a euryhaline fish, might provide suitable environment for halophilic microorganisms.


Author(s):  
Amjed Alsultan ◽  
Dhama Alsallami

Gram-positive pathogens are causing many serious infections that affect humans and result in mild to severe diseases worldwide. In order to survive and initiate infection, enteric pathogens must resist the physiochemical defence factors in the human intestinal tract. One of these defence factors is bile, a potent antibacterial like compound in the intestine. Efflux pumps are the important mechanism by which bacteria resist antibacterial agents such as bile. Efflux of antimicrobial substances outside the bacterial cell is considered as a key factor for intestinal colonization and virulence of enteric pathogens. This paper will review the research conducted on efflux–mediated bile resistance in Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis and Clostridium perfringens. These bacteria colonize in the human & animal gastrointestinal tract and they have a multiple mechanism to resist the innate defences in the gut and antibacterial activity of bile. However, bile resistance in these bacteria is not fully understood. The evidence from this review suggests that Gram-positive pathogens have the ability to active transport of bile. Further research is needed to know how these pathogens sense bile and how bile regulates its virulence factor. In general, therefore, it seems that understanding the specific mechanism of bile resistance in enteric bacteria including gram-positive pathogens may involve in the development of novel strategies to control and treatment of gastrointestinal infections.


2022 ◽  
Vol 23 (2) ◽  
pp. 586
Author(s):  
Jun-Xiu Wang ◽  
En-Bo Ma ◽  
Jian-Zhen Zhang ◽  
Shu-Ping Xing

Tissue homeostasis is critical for maintaining organ shape, size, and function. The condition is regulated by the balance between the generation of new cells and the loss of senescent cells, and it involves many factors and mechanisms. The midgut, an important part of the intestinal tract, is responsible for digestion and nutrient absorption in insects. LmDDX47, the ortholog of DEAD-box helicase 47 from Locusta migratoria, is indispensable for sustaining a normal midgut in the nymphs. However, the underlying cellular and molecular mechanisms remain to be elucidated. In this study, LmDDX47 knockdown resulted in atrophy of the midgut and gastric cecum in both nymph and adult locusts. After LmDDX47 knockdown, the number of regenerative and columnar cells in the midgut was significantly reduced, and cell death was induced in columnar tissue. LmDDX47 was localized to the nucleolus; this was consistent with the reduction in 18S rRNA synthesis in the LmDDX47 knockdown group. In addition, the acetylation and crotonylation levels of midgut proteins were significantly increased. Therefore, LmDDX47 could be a key regulator of midgut homeostasis, regulating 18S rRNA synthesis as well as protein acetylation and crotonylation in the migratory locust.


2022 ◽  
Vol XXVII (156) ◽  
pp. 32-43
Author(s):  
Mirella Tomaz Soares ◽  
Gerson Nakazato ◽  
Renata K. T. Kobayaski ◽  
Marcelo de Souza Zanutto

While diseases in humans seem to be an isolated concern, many are caused by zoonotic agents. The increasingly close contact between pets and their guardians must be considered, and investigations related to pathogens that are frequently found in humans and other animals must be carried out. Escherichia coli, in addition to being a commensal bacterium found in the intestinal tract of many animals, is one of the most frequent causes of several bacterial infections. Recent studies indicate that contact between humans and animals could contribute to the transmission between species of E. coli strains that produce extended-spectrum β-lactamases (ESBL) and AmpC-type lactamases, which are antimicrobial-resistant (multi-resistant). However, more studies are needed for these assumption to be confirmed. This review addresses the zoonotic potential of E. coli based on research related to the finding of pathogenic strains in animals and humans.


2022 ◽  
pp. 119-122
Author(s):  
Cangliang Shen ◽  
Yifan Zhang
Keyword(s):  

2021 ◽  
Vol 26 (6) ◽  
pp. 3110-3113
Author(s):  
SORIN PAUN ◽  
IOAN TANASE ◽  
BOGDAN STOICA ◽  
CEZAR CIUBOTARU ◽  
DIANA PAUN

Although rarely, due to the high variability of the possible tissues encountered in it’s wall, the Meckel’s diverticula can represent a site for tumor development in 0,5-3,2% cases. Data in the literature shows that the most common malignancy at this level is represented by neuroendocrine tumors (NET) the observed incidence of neurendocrine tumors and other primary neoplasia, varies between 12-55%. Moreover, the gastro-intestinal tract was the second primary tumor bearer encountered.


2021 ◽  
Vol 8 ◽  
Author(s):  
Carolina Mesa-Pineda ◽  
Jeffer L. Navarro-Ruíz ◽  
Sara López-Osorio ◽  
Jenny J. Chaparro-Gutiérrez ◽  
Luis M. Gómez-Osorio

The poultry industry is one of the main providers of protein for the world's population, but it faces great challenges including coccidiosis, one of the diseases with the most impact on productive performance. Coccidiosis is caused by protozoan parasites of the genus Eimeria, which are a group of monoxenous obligate intracellular parasites. Seven species of this genus can affect chickens (Gallus gallus), each with different pathogenic characteristics and targeting a specific intestinal location. Eimeria alters the function of the intestinal tract, generating deficiencies in the absorption of nutrients and lowering productive performance, leading to economic losses. The objective of this manuscript is to review basic concepts of coccidiosis, the different Eimeria species that infect chickens, their life cycle, and the most sustainable and holistic methods available to control the disease.


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