We hear a lot about ways to repair leaky gut, including by taking glutamine. Personally, I have a problem with glutamine because it is a major source of glutamate in cells. The enzyme glutaminase, which is found in most cells, converts glutamine into the excitotoxin glutamate, which has been shown to stimulate the growth and invasion of many types of cancer.

But that’s not the only problem with glutamine. It has also been shown to worsen the course of amyotrophic lateral sclerosis (ALS). The natural metabolic fuel for cells lining the gut is the short-chain fatty acid butyrate, which has demonstrated powerful anticancer effects — and not just for colon cancer.

One study found butyrate suppressed and healed stomach ulcers. And other research has shown that it can suppress cancers outside the gut. Deficiency of butyrate production is associated with inflammatory bowel diseases such as Crohn’s disease. Butyrate has also been shown to protect the intestine from alcohol toxicity.

Another set of studies demonstrated how butyrate stimulates reprogramming of colon cells, thus converting colon cancer cells to normal cells that do not proliferate.

We now know that cancer is not a DNA disease; it is a metabolic disease. And butyrate switches those cells to the metabolism of regular colon cells. Normally, certain bacteria in the colon produce butyrate.

But if you’re deficient, supplemental butyrate is available.