Promotes Brain Health Through Gene Expression
One of butyrate's many functions is to influence the activity of genes. Proteins that play a role in gene regulation are called histones. Adding molecules called methyl groups (methylation) to histones can hold back gene production. Adding other compounds called acetyl groups (acetylation) can increase gene production. Reduced histone acetylation is characteristic of many neurodegenerative diseases. Butyrate helps maintain higher levels, thereby allowing for more gene production and better brain functioning. This has been demonstrated in a number of laboratory studies. Sodium butyrate, a form of butyrate commonly used in lab research, was shown to prevent the death of neurons in models of Parkinson's and Huntington's disease. It also limited brain damage and improved behavioral outcomes in stroke, and induced resistance to free radicals. A review by a group of researchers from New York and North Carolina found that sodium butyrate "demonstrated a profound effect on improving learning and memory, particularly in cases of disease-associated or toxicity-induced dementia." In mouse models of Alzheimer's, sodium butyrate restored histone acetylation to increase expression of learning-associated genes. Sodium butyrate, through its ability to increase acetylation, promotes BDNF, an important brain growth hormone; GDNF, which promotes the survival of neurons; and nerve growth factor or NGF, which regulates survival, maintenance, proliferation and growth of many types of brain cell.Increases Energy and Activates GPCR
Well before memory loss shows up in Alzheimer's, the availability of glucose is reduced, which contributes to dysfunction of the mitochondria, the cell's energy factory. A number of lab studies show that butyrate can increase the activity of the mitochondria and help rectify the dysfunction that leads to neurological diseases. Butyrate has also been shown to switch on G protein-coupled receptors (GPCRs). These activate cellular responses to signals coming from outside the cell. Dysfunction of GPCRs is linked to many diseases. In fact, over 40% of prescribed drugs target them. Several types of GPCR can be activated by butyrate, and studies on Parkinson's disease demonstrate that this leads to anti-inflammatory effects in the brain. The conclusion of the review by US researchers was that butyrate had "significant potential as a therapeutic for the brain" and to improve outcomes in patients with neurological disorders.Best Food Sources of Butyrate
All high-fiber foods will be a source of butyrate, but some of the best are resistant starches found in whole grains, oats, rice, legumes and beans. Fructo-oligosaccharides in bananas, onions, leeks, Jerusalem artichoke, sweet potatoes and asparagus are also excellent at allowing butyrate-producing bacteria to thrive. Milk also contains butyrate, with butter being the richest dietary source. The nutrient is also found to a lesser extent in plant oils.