Some researchers believe that over production of histamines contributes significantly to CFS. The article Freshness Counts: Histamine Intolerance gives a nice simple description with just enough technical details to make me happy, especially since it was written by a MD. One section caught my eye
To turn a garden variety amino acid into a powerful biogenic amine, you need to remove its carboxyl group. To accomplish this you need a special enzyme called a decarboxylase (fancy word for “enzyme that chops off carboxyl groups”).
Many species of bacteria and yeast contain the enzyme histidine decarboxylase(HDC), which turns histidine into histamine. So, when meat (or fish) is not immediately consumed or frozen, bacteria get straight to work breaking down the amino acids within it, and one of the by-products is histamine.
The MD focused on bacteria and yeast before it was consumed – that is, acquired during the storage and preparation process of the food. I find myself asking the opposite question — what about those after it is consumed. The microbiome (gut bacteria etc) contains bacteria and yeast too!
So over to PubMed, and the first article(2014) was shockingly on target.
“The model probiotic organism Lactobacillus reuteri ATCC PTA 6475 is indigenous to the human microbiome, and converts the amino acid L-histidine to the biogenic amine, histamine.”
Is this why some CFSers have very severe reactions to probiotics? They may increases an already elevated level of histamines? The article continues onward to describe how a specific gene (eriC) is involved. Another 2013 article look at other aspects of L.Reuteri species and histamine production.
Another article(2013) found “species were identified as Bacillus licheniformis A7 and B. coagulans SL5. ” The species Bacillus Coagulans is found in commercial probiotics – however, I do not believe they use this strain. As a reminder to readers, bacteria is broken down into families, species. strains equivalent to Humans, Italians, Mafia. There are good strains (Michelangelo, Galileo, etc) and bad strains (Mafia god-father). Be very careful not to think that “All italians are in the mafia” or “All italians are great artists”. Both are incorrect. Similarly, with bacteria: Some species are very good (like E.Coli Nissle 1917) and some are very bad (many other E.Coli strains).
A 2010 article reports: “Lactobacillus plantarum, L. brevis and L. casei/paracasei, and Enterococcus faecium and Enterococcus faecalis were identified as tyramine/histamine producers in the sausages.” These are all common in typical commercial probiotics.
There are 200+ article on pubmed dealing with this area.
So how to deal with this issue?
A 2013 article looked at the use of spices and found clove oil, lemongrass and sweet basil oil were effective against one species. A 1996 study found “Cinnamon and clove exhibited a significant inhibitory effect, whereas turmeric and cardamom had a moderate effect.”
How does this relates to the Microbiome Model?
It actually agrees completely. If the stable dysfuctional gut bacteria is rich in strains that produces histidine decarboxylase(HDC) we are in complete agreement. The model states that the symptoms are due to a stable dysfunction (which will vary from person to person). This is just such a subset where histamines are the inducer of the symptoms.