This is a topic that I am interested in.
Butyrate is one of the three predominant short chain fatty acids (SCFAs). The other two predominant SCFAs are acetate and propionate. We can increase SCFAs by eating the right types of soluble fermentable fiber which feeds the healthy SCFA producing bacteria in our gut. Prebiotics also increase SCFAs. Increasing SCFAs in this way increase all 3 predominant SCFAs which include butyrate.
Butyrate interacts with the epithelial cells to increase melatonin production in the gut while propionate and acetate increase melatonin receptors in the gut. In turn, melatonin increases SCFA production in the gut in a pro health cycle that is stimulated by increased fiber intake. Together butyrate and melatonin both help repair the gut mucosal barrier which helps to prevent gut permeability (aka leaky gut) and beyond the mucosal barrier they also strengthen the epithelial barrier to further repair gut permeability. This is very important for maintaining the best health.
The downside is that in some disease states, the SCFA producing bacteria can be very low, in which case SCFA production may be minimal and this can allow the mucosal barrier to become perturbed which allows gut permeability to increase allowing bacteria to escape the colon into the general circulation which causes an inflammatory response by the body to attack these bacteria that the body sees as invaders. This inflammatory response results in significant collateral damage as well as further increased inflammation and oxidative stress which is all bad for our health.
Melatonin and the SCFAs have antiinflammatory and antioxidative effects in the gut aside from their ability to improve gut permeability which is very good for improved health. Unfortunately, SCFAs decline with age and decreased SCFA production in the gut results in decreased melatonin and melatonin receptors in the gut and all of this results in ill health and disease. Exercise increases SCFA production as does fasting.
A few vitamins have shown some ability to increase SCFAs. Fasting can also increase SCFAs. Pistachios can increase SCFAs and also contain significant amounts of fiber. Prebiotics can increase SCFAs.
I wonder if this link to information about butyrate would interest Earth Clinic readers. It was suggested by an Integrative Medicine site in Canada.
pdf of presentation also available. https://www.ihcanconferences.co.uk/downloads/2021/webinars/butyratebodybiowebinarslides.pdf