The third lecture of expert interpretation of "Clinical Expert Consensus on Gastrointestinal Mucosa Protection"!

It is only for medical professionals to read and reference, follow the consensus, and reasonably protect the gastrointestinal mucosa
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The gastrointestinal tract is the organ with the largest contact between the human body and the external environment.
The epithelium of the gastrointestinal tract provides the largest mucosal barrier between the environment and the human body [1].
The secretion of various hormones is closely related to the gastrointestinal mucosal barrier.
especially important
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The gastrointestinal mucosal barrier damage may cause gastrointestinal erosions, ulcers and other digestive system diseases, and also lead to abnormalities in gastrointestinal motility, digestion and absorption, and intestinal microecology [2]
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Therefore, the protection of gastrointestinal mucosa has always been valued by gastroenterologists
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Based on this, the Gastrointestinal Hormone and Mucosal Barrier Group of the Gastroenterology Branch of the Chinese Medical Association has compiled the "Clinical Expert Consensus on Gastrointestinal Mucosal Protection (2021, Fuzhou)" (hereinafter referred to as the "Consensus"), which will be published in December 2021.
Officially published in "Chinese Journal of Digestion"
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In order to help clinical medical workers deeply understand the content of the consensus, the "medical community" specially invited a number of experts to share relevant knowledge in a series
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The last issue of "Medical Community" specially invited Professor Li Jingnan, the corresponding author of "Consensus", to give a comprehensive introduction and interpretation of the relevant content of "Consensus"
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In this issue, we invite Professor Zhang Bingyong, a member of the consensus editorial board and the Department of Gastroenterology of Henan Provincial People's Hospital, to further interpret the relevant content of the consensus
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 Expert introduction Layers of defense, building gastrointestinal mucosal protective function The mucosa is the body's first-line barrier to resist pathogen invasion and maintain the stability of the internal environment.
The gastrointestinal mucosal barrier exerts its protective function through its three-dimensional network protection structure
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"The protective function of the gastric mucosal barrier is mainly related to the 'mucus-bicarbonate-phospholipid' barrier, the junction between epithelial cells and the composition of gastric juice [2]
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" Professor Zhang Bingyong said
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The "Consensus" pointed out that the "mucus-bicarbonate-phospholipid" barrier is the first line of defense of the gastric mucosa, and plays a role in protecting the gastric mucosa epithelial tissue from acid reverse osmosis and preventing epithelial hydrolysis caused by pepsin penetration.
important role
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The connection between epithelial cells and cells is the second barrier of gastric mucosal defense.
The integrity of epithelial cells and the hydrophobicity of phospholipids are important factors in resisting acids and water-soluble harmful substances.
The closed structure formed by tight junctions can prevent acid and Protease reverse osmosis
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Gastric juice contains many components that reduce the bacteria that colonize the stomach, including acids, immunoglobulins, and lactoferrin
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Therefore, pathogenic microorganisms rarely survive in the acidic environment of the stomach
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In addition, the mucus secreted on the surface of the gastric mucosa can not only act as a lubricant to reduce the mechanical damage of food to the stomach, but also effectively reduce the ability of bacteria to access the gastric epithelium
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"The protective characteristics of the intestinal mucosal barrier are not exactly the same as those of the gastric mucosa.
The special structure of mucus and intestinal epithelial cells is the main feature of the intestinal mucosal barrier
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" Professor Zhang emphasized
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The intestinal mucus layer is composed of two types of glycosylated mucins.
The mucous layer of different intestinal segments has different characteristics.
The mucus layer is continuously consumed and replenished, which is the first immune defense line of the intestinal tract [3]
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Professor Zhang pointed out that the intestinal mucosal barrier should not be regarded as a static structure, but is highly dynamic, which responds to internal and external stimuli
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There are many risks.
The gastrointestinal mucosal barrier is "embarrassed on all sides".
As the largest barrier organ in the human body, the gastrointestinal mucosa is composed of mechanical barriers, chemical barriers, immune barriers and biological barriers, and the secretion of various hormones and the function of the gastrointestinal mucosal barrier are also closely related
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The mucosal barrier of the gastrointestinal tract plays an important physiological role in the human body, but it is also "fragile".
When the mucosal damage factors are greater than the defensive factors, related mucosal damage may occur
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Ischemia-reperfusion injury (IR) mechanism, drugs, physicochemical, infection, psychological and other factors can lead to damage to the gastrointestinal mucosal barrier [2]
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The gastrointestinal mucosal barrier is particularly sensitive to IR, which is an important pathophysiological basis for the occurrence of stress ulcers
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Severe trauma, surgery, and critical illnesses (including digestive system diseases) can easily induce gastrointestinal ischemia, leading to apoptosis of gastrointestinal epithelial cells
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A large number of reactive oxygen species generated during reperfusion and the induced inflammatory mediator cascade effect lead to subcellular damage, destruction of intercellular tight junctions, and increased mucosal permeability [2]
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Prof.
Zhang pointed out that IR-induced oxidative stress can damage the mucus barrier of the gastrointestinal tract, which is mainly manifested by reduced mucus and altered mucus properties
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The destruction of the acidic environment caused by hypoxia is related to the bicarbonate barrier, and free radicals such as reactive oxygen species will destroy the sugar-based macromolecules in the mucus, making the mucus lose its viscosity, hydrophobicity and barrier function
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Gastrointestinal barrier dysfunction caused by IR is also thought to be associated with pancreatic enzyme activation, neutrophil adhesion, and calcium overload
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Intestinal barrier damage is not easy to observe, but it should not be ignored
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Faced with such a "fragile" gastric mucosal barrier, how can we maintain the protective function of the gastrointestinal mucosal barrier? From the perspective of "gut", maintaining the protective function of the gastrointestinal mucosa mucosal barrier damage is the common pathological basis of chronic gastritis, peptic ulcer, gastroesophageal reflux disease, drug-induced gastrointestinal injury, inflammatory bowel disease and other digestive diseases
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The "Consensus" pointed out that intestinal flora can play an important role in maintaining the mucosal barrier function of the gastrointestinal tract
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The mucus layer in the gastrointestinal mucosal barrier is divided into two parts: the inner layer is the tight junction layer, which secretes protective polypeptides with antibacterial effects and is relatively sterile; the outer layer is thicker and looser, with a large number of intestinal flora and its product
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There are more abundant bacteria and bacteria in the intestinal lumen, which play an important role in regulating the barrier function of the intestinal mucus layer and participate in the maintenance of the mucosal barrier
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The intestinal flora promotes tight junctions between cells and mucosal repair by resisting the colonization of foreign microorganisms, secreting mucokines and related metabolites, activating immune cells to produce antibodies and cytokines [4]
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Studies have shown that in a mouse model of enteritis, Akkermansia mucinophilus can enhance the integrity of the epithelial cell layer after adhesion of intestinal epithelial cells [5]
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It can be seen that the intestinal flora plays an important role in maintaining the mucosal barrier function of the gastrointestinal tract
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Professor Zhang said that this is the body's physiological protection of the gastrointestinal mucosa.
In addition, rational drug use can also protect the gastrointestinal mucosal barrier
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Rational use of drugs to protect the gastrointestinal mucosal barrier Professor Zhang pointed out that when the gastrointestinal mucosa is damaged, it is recommended to use gastrointestinal mucosal protective agents to repair the mucosa
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According to the pharmacokinetic mode of action of mucosal protective agents, they are divided into exogenous and endogenous mucosal protective agents.
Exogenous mucosal protective agents mainly play a mucosal protective effect by promoting mucus secretion; Stabilizing cell membranes, increasing mucosal protective factors, increasing mucosal blood flow and other mechanisms play a role.
In addition to protecting the gastric mucosa, it may also have a certain protective effect on the small intestinal mucosa [2]
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"If the patient has gastrointestinal mucosal damage, it is recommended to choose endogenous protective agents such as teprenone, rebamipide and other drugs to treat related diseases caused by the damage.
If necessary, consider combining endogenous protective agents with PPIs.
Combined use
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" Professor Zhang added
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Studies have shown that teprenone combined with PPI in the treatment of non-atrophic gastritis has a significant effect on reducing gastric mucosal inflammation in patients with non-atrophic gastritis[6,7]
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The "Consensus" also recommends that different mucosal protective agents can be used in combination, and can be used in combination with PPI if necessary, but attention should be paid to the occurrence of adverse reactions
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Exogenous mucosal protective agents contain metal ions, and long-term use may cause toxic accumulation, resulting in immeasurable damage to the human body, and the protective effect of exogenous mucosal protective agents is short-term [8,9], and is not suitable for long-term use by patients
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The endogenous mucosal protective agent teprenone can act on different targets of the mucosal barrier and provide protection from multiple aspects.
In addition to protecting the gastric mucosa, it may also have a certain protective effect on the small intestinal mucosa
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Teprenone can increase the content of nitric oxide synthase and nitric oxide in mucosal tissue, promote the synthesis of local endogenous prostaglandins, upregulate the expression of heat shock proteins, and play a role in repairing the mucosa [2]
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Summary: As the largest mucosal barrier organ in the human body, the gastrointestinal mucosa not only provides the nutrients needed by various organs of the human body through digestion and absorption, but also provides nutrients through functions such as the gut-liver axis, the gut-lung axis, the gut-brain axis, and the neuroendocrine function.
Contact with other organs, affecting the function of related organs, as well as the occurrence, development and prognosis of diseases [2]
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Strengthening measures to protect the gastrointestinal mucosa has important clinical significance for the prevention and treatment of diseases
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As a gastric mucosal protective agent that has attracted much attention in recent years, teprenone can not only protect the gastrointestinal mucosa, but also prevent drug-induced small intestinal mucosal damage caused by non-steroidal anti-inflammatory drugs (NSAIDs) [10].
It is an ideal choice for patients with damaged gastrointestinal mucosa, and it is expected that its wide application in clinical practice will bring more benefits to patients
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After reading today's expert sharing, do you still feel unfulfilled? On May 10th, Professor Lin Rong will continue to bring us a wonderful interpretation of "Consensus", which is not to be missed! Click the link below to view the in-depth interpretation of the previous excellent article "Clinical Expert Consensus on Gastrointestinal Mucosa Protection" - the official lecture! The second lecture of expert interpretation of "Clinical Expert Consensus on Gastrointestinal Mucosa Protection"! The author talks about the clinical points of gastrointestinal mucosal protection.
References: [1] Cao Shan, Wang Jingtong, Liu Yulan.
Journal of Gastroenterology and Hepatology.
2007; (02): 198-200.
[2] Chinese Medical Association Digestion Gastrointestinal Hormones and Mucosal Barrier Group of the Chinese Society of Diseases.
Chinese Digestive Journal.
2021;41(12):14.
[3]Paone P,et al.
Gut.
2020 Dec;69(12):2232-2243.
[4 ]Allam-Ndoul B, et al.
Int J Mol Sci.
2020; 21(17): 6402.
[5] Bian X, et al.
Front Microbio.
2019; 10: 2259.
[6] Tsukamoto Y, et al.
J Clin Gastroenterol.
1995;20 Suppl 2:S40-3.
[7]Xiong L,et al.
Dig Liver Dis.
2015;47(4):280-284.
[8]Yang Zhou.
China Minkang Medicine,2019 , 31(17): 37-39.
[9] Gao Yan.
Chinese Prescription Drugs, 2020, 18(08): 62-63.
[10] Tarnawski A, et al.
Scand J Gastroenterol Suppl.
1995; 208: 9-13 .
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