Intestinal Permeability, Butyrate & the Blood-Brain Barrier

The blood-brain barrier (BBB) is like an invisible fence surrounding the central nervous system of your brain. The BBB lets friendly molecules like water, glucose, amino acids and select others into brain cells and keeps everything else out via a combination of passive diffusion and active transport.

As a highly selective permeability barrier, the BBB functions similarly to the intestinal lining. Intestinal barrier function determines which elements may be absorbed into the body and which will be barred entry. So it is interesting to consider that gut barrier function may have a direct effect on blood-brain barrier function.

Last year, Science Translational Medicine published a study conducted by a multinational team based in Sweden, Singapore and the United States comparing the blood-brain barrier function of two groups of mice. Researchers found that in “germ-free mice”, raised from birth in a sterile environment without any bacteria present in their intestines, BBB function was significantly impaired compared to that of mice exposed to normal gut bacteria throughout their lives.

Interestingly, when the researchers gave sodium butyrate to the germ-free mice, favorable changes in brain molecules were observed, notably an increase in the expression of occludin, a molecule required for healthy BBB function. Butyrate is a short chain fatty acid normally produced by the fermentation of dietary fiber by colonic bacteria. Without bacteria, no butyrate.

Therapeutically, butyrate is known to help mediate the colonic inflammatory response and to promote healthy gut barrier function by supporting the formation of endothelial tight junctions. Sodium butyrate is an important support ingredient in Permeability Select™, the newly updated leaky gut formula from Moss Nutrition.

By Diana Allen, MS, CNS; Product Development Manager

07/24/2015 – Moss Nutrition Digest #4


Braniste V, et al. The gut microbiota influences blood-brain barrier permeability in mice. Sci Transl Med. 2014 Nov 19;6(263):263ra 158. (