What role does BDNF play in gut health?

BDNF (Brain-Derived Neurotrophic Factor) is a protein best known for its role in the nervous system, but it also plays a significant part in gut health. It is produced by enteric neurons and immune cells, influencing gut motility, barrier function, and neuronal plasticity in the enteric nervous system. Animal studies show that BDNF can have anti-inflammatory effects and regulate intestinal permeability. In humans, altered BDNF levels have been associated with irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). However, the evidence is largely mechanistic, based on animal or cell models; large clinical trials are lacking. Direct benefits from BDNF measurement or supplementation for gut health are not established. Genetics (e.g., BDNF Val66Met polymorphism) may affect expression, but effect sizes are small and not actionable for personalized nutrition. Beware of exaggerated marketing claims. Overall, BDNF is an interesting but insufficiently validated factor in gut health.