Neural Hardware

Blood-Brain Barrier

A selective membrane that controls which molecules enter the brain from the bloodstream — protecting and filtering neural tissue.

The Blood-Brain Barrier (BBB) is a semi-permeable membrane of endothelial cells that separates the bloodstream from the brain's extracellular fluid. It tightly controls which molecules can enter the brain—protecting neural tissue from toxins while allowing essential nutrients and signaling molecules.

Key Functions

  • Protection — blocks pathogens, toxins, and many drugs
  • Selective transport — allows glucose, amino acids, and specific metabolites
  • SCFA passage — short-chain fatty acids from gut fermentation can cross and reduce neuroinflammation
  • Gut-brain link — microbiome metabolites influence brain health through BBB transport

In ONDA Life

Prebiotic fiber and a healthy microbiome produce SCFAs that cross the Blood-Brain Barrier to support cognitive function. See the Gut-Brain Axis article.