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Microbiota, Dysbiosis, SIBO and Histamine Intollerance


The Intestinal Microbiota, or Intestinal Flora, is the community of live bacteria resident in the digestive tract.

All these microorganisms coexist with us, performing a series of essential functions: synthesis of substances useful for the body, regulation of the immune system, protection against pathogenic bacteria, functional and structural development of the gastrointestinal tract.


A Microbiota in a condition of balance between the microbial populations that compose it is fundamental for the general health of the organism, and it is defined Eubiosis

When this balance is lost and the beneficial species no longer manage to control the "bad" ones, it is passed from a condition of Eubiosis to one of Dysbiosis.

In relation to the triggering principle, we have different types of Dysbiosis:

> Deficiency dysbiosis: caused by a population deficit of intestinal bacterial flora, often favored by a diet poor in soluble (prebiotic) fibers, from fruits and vegetables, and rich in packaged foods.


> Fermentative dysbiosis: caused mainly by a diet too rich in simple sugars, sugars and refined flours and insoluble fibers that are not digested and assimilated, but are used by a series of bacteria to implement fermentation processes.

> Rotting dysbiosis: caused by a diet rich in animal fats and proteins.

What is the SIBO? 

SIBO (Small Intestinal Bacterial Overgrowth) is a form of dysbiosis specific to the Small Intestine

The small intestine is the section of the gastrointestinal tract that connects the Stomach with the large intestine, the Colon, whose function is to digest and absorb food.

It is distinguished in 3 parts:

Duodenum (where food is poured from the stomach)

Jejunum and Ileus (which empties food that was not digested in the Colon).

>>> Symptoms associated with Intestinal Dysbiosis and SIBO




Abdominal pain

Gastroesophageal reflux

Poor digestion

Recurrent cystitis

Candidiasis and Mycosis 

Sleep disorders

Tiredness and fatigue

Dyspnea (shortness of breath)

Migraines and a headache 

Skin problems (Dermatitis, Psoriasis)

Fragile hair and nails

Low Immune defenses

Emtional disorders

Causes that can bring to Dysbiosis and SIBO:

Food Intolerances

Stress and Anxiety


Improper feeding

Alcohol consumption

Bacterial infections

Intestinal pathologies

Altered intestinal permeability 

Hypochloride (decreased acid secretion from the stomach)

Anatomical abnormalities of the digestive system (diverticula, stenosis)

Prolonged treatments with drugs such as antibiotics, atiacids or proton pump inhibitors.

What is Histamine Intolerance?

Histamine is a substance belonging to the group of biogenic amines,

 nitrogen compounds, which are formed by the transformation of amino acids and which are found in food by the action of enzymes generated by microorganisms.

Among the most significant biogenic amines would be: histamine, cadaverine, putrescine, tyramine and tryptamine.

The true mechanism of histamine intolerance is under investigation, but it is believed to be related to an imbalance between its accumulation and its degradation by the detoxification systems at the intestinal and hepatic levels.

> In a healthy individual, histamine is broken down regularly with the help of two enzymes: DAO and HNMT.

DAO is more present in the digestive tract, kidney and placenta, while HNMT has a wider location throughout the body.

DAO is responsible for degrading histamine that is outside of cells, while HNMT degrades histamine inside cells

> It can be differentiated into two types, the endogenous, which occurs inside the body: located in cells of the Connective Tissue in the skin, the mucous membranes of the digestive tract and the respiratory tract,

and exogenous, which comes from the outside: present in all foods to a greater or lesser extent and that we incorporate by diet.


> When the system is in balance 

Stores in mast cells, immune system cells involved in allergic responses and inflammatory processes.

 Performs various functions involved in the immune response against pathogenic microorganisms (capable of causing disease conditions)

 It is a chemical mediator (allows communication between cells), allows proper digestion (stimulates the secretion of gastric juices) 

 Participates in the regulation of the sleep-wake cycle and appetite.


>>> When the System is out of balance

The DAO enzyme is not present in the body in sufficient quantity to be able to degrade histamine after meals in the small intestine.

 The ingestion of certain foods, precisely called histamine liberators, in subjective and variable quantity, can cause a toxic picture:

  • Smoked or canned fish: anchovies, sardines, tuna, mackerel, herring

  • Seafood 

  • Cured and semi-cured cheeses

  • Cured meat and sausages

  • Ketchup and other industrial souces

  • Some vegetables and fruits: spinach, eggplant, tomatoes, avocado, strawberries, pineapple

  • Alcoholic beverages: wine, cava, beer, cider, distilled


With histamine intolerance, symptoms may appear when certain foods are consumed, but the mechanism is different from that of a food allergy.

(See here the difference between Intollerances and food Allergies).

Some of the symptoms are similar to those of a true allergic reaction, but histamine intolerance does not involve immunoglobulin E (IgE), so skin and allergy tests will be negative.

> Because of this, symptoms may not be immediate.

Symptoms can occur every time a certain limit is reached, making it difficult to identify a particular food as the culprit.

For example, you may have eaten foods rich in histamine in the morning, and in the afternoon you may have eaten a meal low in histamine.

But, it is possible that the evening meal will be enough to cause you to exceed your tolerance level, so you would have symptoms in the afternoon.

You might think that your symptoms were due to the afternoon meal, but in reality the morning food was the most important factor.


 Tolerance to histamine varies from person to person, and the amount of histamine tolerated should be deduced by personalized tests and tests.

Correcting the diet with foods low in histamine is the ideal treatment.

 Some people can only tolerate very small amounts, and some people can tolerate larger amounts.

  Its excess can manifest with a large number of symptoms, even extraintestinal, which complicates the diagnosis.

>>> Symptoms associated with Histamine Intolerance:



Dizziness or dizziness


Swelling/ inflammation of tissues. 

Temperature change

Nasal congestion


Anxiety, depression, mood imbalances

Shortness of breath

Digestive problems



Abdominal cramps


In the light of the data presented, the role of food and integration in the management of these conditions seems important.

The diet will be aimed at an initial exclusion of those foods responsible for exacerbation of symptoms and worsening of the pathology, followed by a gradual reintroduction.


If you have any symptoms, questions or want to control your situation,

call me or write me and book a Naturopathic Consultation.

I’ll be happy to help you!

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