Why Not Directly Supplement Propionate?

Short-chain fatty acids (SCFAs) are known to be "good" for human health. But are they all created equally? Let's dive into propionate.

When we study nutraceutical ingredients, they’re often studied in healthy individuals or animals. But the majority of Americans aren’t healthy, and they certainly aren’t the same as mice. For example, nearly three-of-four Americans are overweight or obese.

Additionally, data from the Centers for Disease Control indicate that roughly one-third of adults (96 million Americans) have prediabetes, and approximately 10% of Americans have diabetes itself.

So, given the majority are unhealthy, are we truly studying ingredients in the market in which we’re selling? Or, are we studying a narrow and rare cohort of healthy people?

One proposed nutraceutical solution to improve human health is the short-chain fatty acid (SCFA), propionate. Because propionate is a SCFA, and SCFAs are generally recognized to be ‘good,’ propionate is assumed to be ‘good,’ as well. Certainly, there are studies showing the health-promoting effects of propionate. But, due to propionate's high prevalence in processed foods such as meats, dairy products and sweets, the average American is consuming enough propionate in the diet, making direct supplementation unnecessary.

Moreover, direct supplementation in vulnerable populations may have potentially negative health impacts including higher levels of c. difficile, impaired glucose metabolism, or cognitive decline.

Propionate may also alter metabolism and contribute to obesity if consumed in high quantities. This metabolic disruption may stem from reductions in insulin function. (Ref. 1, Ref. 2, Ref. 3, Ref. 4)

When we think of SCFAs, we think of fiber and resistant starch fermenting in the colon. That’s a good thing. They ferment to produce several SCFAs, including propionate. There are also prebiotics that can stimulate propionate. That's also a good thing. In this manner, it’s best to let food be thy medicine.

The bottom line: indirect propionate production through foods, prebiotics and resistant starches is good. We do not, however, believe in a direct supplement of propionate itself.