negative regulation of intestinal absorption

Definition

Target type: biologicalprocess

Any process that stops, prevents or reduces the frequency, rate or extent of intestinal absorption. [GO_REF:0000058, GOC:BHF, GOC:rl, GOC:TermGenie, PMID:12469120]

Negative regulation of intestinal absorption is a complex process that involves a coordinated effort of various mechanisms to reduce the uptake of nutrients and other molecules from the lumen of the intestine into the bloodstream. This process plays a crucial role in maintaining homeostasis, preventing nutrient overload, and regulating the absorption of specific substances.

**Factors influencing intestinal absorption:**

* **Hormonal regulation:** Hormones like cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) are released in response to food intake and signal the gut to reduce nutrient absorption. CCK promotes satiety and reduces gastric emptying, while GLP-1 and PYY slow down intestinal motility and decrease nutrient uptake.
* **Neural regulation:** The nervous system plays a vital role in regulating intestinal absorption through the enteric nervous system (ENS) and the autonomic nervous system. The ENS, the gut's intrinsic nervous system, controls local reflexes related to nutrient absorption, while the autonomic nervous system receives signals from the brain and modulates intestinal function.
* **Dietary factors:** The composition of the diet significantly affects intestinal absorption. High-fat meals trigger the release of hormones that inhibit absorption, while high-fiber diets can slow down nutrient uptake.
* **Gut microbiota:** The trillions of bacteria residing in the gut can influence intestinal absorption by producing metabolites that affect the expression of genes involved in nutrient uptake.
* **Epithelial cell function:** The epithelial cells lining the intestine are responsible for the uptake of nutrients and other molecules. Tight junctions between these cells regulate the permeability of the intestinal barrier and prevent the passage of unwanted substances.

**Mechanisms of negative regulation:**

* **Reduced expression of transport proteins:** The expression of specific transport proteins responsible for the uptake of nutrients, such as glucose transporters and amino acid transporters, can be downregulated by various factors, leading to decreased absorption.
* **Increased secretion of digestive enzymes:** The release of digestive enzymes, such as lactase, can be enhanced by factors like hormonal signals or changes in pH, which can break down nutrients before they are absorbed.
* **Altered gut motility:** Reduced intestinal motility can lead to decreased nutrient absorption by prolonging the time food spends in the gut and increasing the opportunity for breakdown and excretion.
* **Increased excretion of nutrients:** The gut can actively excrete specific nutrients through mechanisms like bile salt secretion or the release of certain metabolites.
* **Changes in intestinal barrier permeability:** Tight junctions between epithelial cells can be regulated by various factors, increasing intestinal permeability and leading to reduced absorption.

**Consequences of negative regulation:**

* **Reduced nutrient uptake:** Negative regulation of intestinal absorption can lead to a reduction in the uptake of essential nutrients like vitamins, minerals, and carbohydrates, potentially affecting overall health.
* **Satiety and weight regulation:** Negative regulation contributes to feelings of fullness and reduces calorie intake, playing a role in maintaining a healthy weight.
* **Prevention of nutrient overload:** Negative regulation prevents the absorption of excessive amounts of nutrients, protecting the body from potential toxicity or imbalances.
* **Specific nutrient absorption regulation:** This process allows for the selective regulation of the absorption of certain nutrients based on the body's needs.

**In summary,** negative regulation of intestinal absorption is a multifaceted process that involves various physiological and biochemical mechanisms. It plays a crucial role in maintaining homeostasis, regulating nutrient uptake, and preventing nutrient overload. Understanding the complexities of this process is essential for optimizing gut health and maintaining overall well-being.'
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Proteins (1)

Compounds (2)