Direction of the brain--gut pathway in functional gastrointestinal disorders

The gut–brain axis is a bidirectional communication system that connects the gastrointestinal tract and the brain. This interaction is mediated through multiple pathways, including the vagus nerve, hormonal signals, immune responses, and chemical messengers produced by gut microbes.Microbial Contributions to Brain FunctionGut microbiota contributes significantly to brain function by producing neuroactive compounds. These include neuroactive compounds that influence neurotransmitters such as...

DefinitionIrritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by recurrent combinations of abdominal pain, bloating, diarrhea, or constipation.Pathophysiology of irritable bowel syndromeIts pathophysiology is multifactorial, involving disturbances in motility, sensory processing, microbial balance, barrier integrity, and gut–brain communication. These mechanisms interact to produce symptoms that vary across IBS subtypes.Altered Motility PatternsDisordered...

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...

Digestion begins with a cephalic phase that prepares the digestive system to receive food. When our brain processes visual or olfactory information about food, it triggers impulses in the cranial nerves innervating the salivary glands and stomach to prepare for food.

Gastrointestinal or GI motility disorders are characterized by irregular gastrointestinal tract movements, disrupting food transit from the mouth to the anus. They are caused by damage or dysfunction in gut muscles or nerves. These disorders can cause symptoms such as severe constipation, diarrhea, abdominal pain, and swallowing difficulties. Disorders can affect any segment of the GI tract and range widely in severity, from common conditions like GERD to life-threatening conditions like...

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...