Histamine Producing Gut Bacteria
Histamine producing gut bacteria is one of the leading causes of histamine intolerance in my clients.
It is well established that histamine can be produced by bacteria in fermented foods, but there is an emerging body of research, showing that the microbes within the human gut can also produce, regulate, or degrade histamine.
We can therefore no longer assume that mast cells are the sole source of histamine in the human body.
Indeed, one of the key sources within my client base is dysbiosis. Once the histamine producing bacteria is addressed the histamine intolerance reverses.
Despite this clinical experience, the research is still emerging. Here is what we know so far.
Histamine Producing Gut Bacteria Study 1
There has long been a hypothesis that there is a link between the microbiota and asthma.
A recent study found the amount of histamine producing bacteria in asthmatics was significantly higher than non-asthmatics.
Interestingly, the type of histamine secreting bacteria was Escherichia coli, Morganii morganii, and Lactobacillus vaginalis commonly associated with fish-related food poisoning. Furthermore, the higher the levels of Morganii morganii the more pronounced the symptoms.
As a result is hypothesized that increased levels of histamine producing gut bacteria, interact with histamine receptors, to cause the asthma symptoms.
Histamine Producing Gut Bacteria Study 2
It is well established that the immune system is heavily dependent on how the gastrointestinal tract handles histamine.
Histamine can have both pro-inflammatory or anti-inflammatory effects on the immune system depending on which histamine receptor is activated.
There are currently four known histamine receptors. H1R and H4R are thought to be pro-inflammatory and initiate an immune reaction. H2R and H3R are thought to be anti-inflammatory and halt an immune reaction.
However, in one study, it was demonstrated that a moderate histamine producing bacteria, stimulated the inflammatory H1 receptor. Whilst in two other studies, it was demonstrated that higher histamine producing bacteria blocked the anti-inflammatory H2R.
Interestingly, increased histamine levels are increased in patients with irritable bowel syndrome and inflammatory bowel disease, and it was recently shown that inflammatory bowel disease patients have decreased H2 receptor function. Could this be due to very high levels of histamine producing gut bacteria?
It is hypothesized that the amount of histamine produced by the bacteria determines whether the immunoregulatory effects is pathological versus protective. This hypothesis is consistent with research into the progression of mast cell activation.
Histamine Producing Gut Bacteria Study 3
A recent 2017 study, identified that the production or degradation of histamine and other biogenic amines was a common function of microbiota inhabitants. That is it was a key not incidental function.
A small number of strains could produce histamine at levels well above the maximum safety limits, however, the number increased dramatically when incubated with other biogenic amines (particularly cavedeine and putrescine).
This led researchers to conclude that histamine appears to have a complex system of regulation with other biogenic amines. For example, Escherichia coli, a histamine producing bacteria well linked to histamine food poisoning, is only toxic because of the presence of other biogenic amines.
Histamine Producing Bacteria Study 4
Another 2017 study, of 51 saliva samples, collected from patients with respiratory problems, were tested for 255 bacteria. 50 strains of Klebsiella pneumoniae were identified, and 11 of the 50 strains, were histamine producing. Histamine concentrations were at levels sufficient to cause histamine poisoning.
Klebsiella pneumoniae was found to be able to be treated with the antibiotic Triemethoprim. In my experience, Klebsiella pneumoniae is also able to be treated with herbs.
A List of Histamine Producing Gut Bacteria
There needs to be a fair degree of caution in relying upon the lists that follow. This list will emerge and be refined in line with further research.
Firstly, these lists are of species, not strains, and it is the strains that determine the histamine reaction. I have not listed the strains as the gastrointestinal tests do not currently report them.
Secondly, there are no large-scale studies, of the 10,000s of microbial species. Most major studies look at no more than 125 strains. Given what seems to be a complex interplay between the microbiome these types of studies are needed.
Thirdly, many of the earlier studies, are not of the human gut biome. I have included high histamine strains where there is a high degree of consensus. I have also included all strains tested with human samples. This is imperfect. A more conclusive list will emerge in time.
With those caveats here is a list of what we know to date.
The histamine producing gut bacterial strains in their own right:
- Morganella morganii (also high tyramine) – this is able to be tested on the GI-Map
- Hafnia alvei
- Lactobacillus vaginalis
- Lactabacillus saerimneri strain 30a
- Klebsiella pneumoniae – this is able to be tested on the GI-Map.
The tyramine producing bacterial gut bacteria in their own right:
- Most enterococcus species
- Escherichia coli (also mast cell activation ) – this is able to be tested on the GI-Map
- Klebsiella pneumoniae (also mast cell activation) -this is able to be tested on the GI-Map
- Morganella morganii (also high histamine) – this is able to be tested on the GI-Map
The putrescine and cadaverine producing gut bacteria that increase histamine levels:
- Most gram-negative bacteria – some of which are able to be tested on the Gi-Map including Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Helicobacter pylori, and Salmonella
- Escherichia fergusonii
- Enterobacter cloacae
- Serratia liquiefaciens
- Serratia marcescens
Other strains strongly linked to histamine food poisoning:
- Proteus vulgaris
- Proteus mirabilis – this is able to be tested on the Gi-Map
- Entrobacger aerogenes
- Raouletella planticola
- Raulella ornithinolytica
- Citrobacter freundii – this is able to be tested on the GI-Map
- Pseudomnas fluourescens
- Photobacterium damselae
The 2017 study highlighted for the first time that many microbial strains can become histamine producing in the presence of other biogenic amines. The significance of these findings is not yet fully understood particularly as some of the strains have not been implicated in histamine food poisoning. Nevertheless, the strains which were identified as problematic were:
- Bifidobacterium adolecentis
- Bifidobacterium longum
- Bifidobacterium pseudocatenulatum
- Enterococcus species (including faceium, faecalis, and avium)
- Lactabacillus crispatus
- Lactabacillus fermentum
- Lactabacillus gasseri
- Lactobacillus salivarius
- Streptococcus vestibularis
Research into the role of histamine producing gut bacteria is still in its infancy. Never the less there is mounting evidence that one of the hidden sources of histamine intolerance is the gut microbiome.
In the absence of conclusive research, much progress can still be made even in the most sensitive people.
Whilst it is not proven that food poisoning causes the change in the microbiota, the fact that many of the infections are linked to histamine food poisoning, suggests that good food hygiene should be a key preventative strategy.
Furthermore, many of the key offenders can be tested on DNA based gut tests, such as the Gi-Map. This is an easy first step, to test for pathogenic bacteria, clearly linked to chronic symptoms, and which are easily treated with herbal remedies.
Improved techniques are also making it possible to sequence the microbiome including the richness, evenness, and diversity of the species present.
I am increasingly using the Viome gut test, to start to work with the whole gut biome. I suspect that these types of sequencing will ultimately hold a lot of the answers to histamine producing gut bacteria.
In addition to histamine producing bacteria, there is also a range of species which act to degrade histamine, which can be found in my e-book The Insider’s Guide to the Therapeutic Use of Probiotics for Histamine Intolerance.
Almayah, A. A., and A. H. Issa. “Ibrahim Hk “Virulence factors and antibiotic susceptibility patterns of Klebsiella pneumonia strains Histamine producing bacteria isolated from sputum”.” Sci. J. Med. Res 1.4 (2017): 103-109.
Björnsdóttir-Butler, Kristin, et al. “Development of molecular-based methods for determination of high histamine producing bacteria in fish.” International journal of food microbiology139.3 (2010): 161-167.
Huang, Yvonne J., et al. “The microbiome in allergic disease: Current understanding and future opportunities—2017 PRACTALL document of the American Academy of Allergy, Asthma & Immunology and the European Academy of Allergy and Clinical Immunology.” Journal of Allergy and Clinical Immunology 139.4 (2017): 1099-1110.