抑制受体PD-1调节肠道IgA选择和细菌组成

The pathophysiology of gastritis begins with the colonization of the stomach lining by Helicobacter pylori (H. pylori). This bacterium spreads mainly via the oral-oral route through saliva or shared utensils, and can also be transmitted in overcrowded or unhygienic environments through contaminated water, despite its brief survival outside the body.ColonizationOnce ingested, H. pylori enters the stomach and begins colonization by navigating through the mucus layer lining the stomach wall. It...

The human gastrointestinal (GI) tract is characterized by distinct physicochemical conditions that shape its microbial communities. Among these, the stomach presents a particularly challenging environment for microbial colonization due to its highly acidic pH, ranging from 1 to 3. This extreme acidity effectively limits microbial density. However, certain acid-tolerant microorganisms are capable of surviving in this niche. Notably, Helicobacter pylori can colonize the gastric mucosa,...

The gut microbiota includes trillions of microorganisms that colonize the human gastrointestinal tract, including bacteria, archaea, viruses, and fungi. This complex ecosystem plays a critical role in maintaining intestinal and systemic health. Most of these microbes inhabit the large intestine, establishing a relatively stable and diverse community that contributes to gut homeostasis through various metabolic, immunological, and protective mechanisms.Dominant bacterial phyla, such as...

The gastrointestinal tract, responsible for the digestion and absorption of nutrients, is safeguarded by the intestinal barrier, which consists of secretory, physical, and immune components. At the forefront is the secretory barrier, composed of essential elements such as mucus, gut microbiota, and defense proteins. They collaborate to break down food particles, facilitate nutrient absorption, and maintain optimal gut health. These secretory components ensure the smooth functioning of the...

Crohn’s disease is a chronic, relapsing form of inflammatory bowel disease characterized by segmental, transmural inflammation that can affect any part of the gastrointestinal tract. Its pathogenesis arises from a combination of genetic susceptibility, environmental exposures, epithelial barrier dysfunction, and immune dysregulation. Together, these factors lead to an exaggerated immune response against components of the gut microbiome.Genetic and Environmental InfluencesMultiple genetic...

Irritable Bowel Syndrome (IBS) is characterized by functional disturbances in the gastrointestinal system, presenting a cluster of symptoms without evident structural or biochemical abnormalities. It primarily affects the large intestine and may cause abdominal pain, bloating, excessive gas, diarrhea, constipation, or both.
IBS is a chronic condition that can persist over a long period or recur frequently.
The pathogenesis of IBS involves a complex interplay of the following factors:
Altered...