Function of the intestinal immune system and biogenic amines

Intestinal immune system, intestinal flora and biogenic amines

The intestine is not only responsible for digestion. It is also a central point of contact between food, microorganisms, the mucous membrane and the immune system. Especially the Intestinal flora, the intestinal barrier and certain immune cells play an important role.

At the same time, modern diets, highly processed foods, free amino acids, fermentation products and biogenic amines increasingly discussed in connection with intestinal flora, digestion, histamine and individual tolerance.

In this article you will learn how the intestinal immune system is structured, what role the intestinal flora plays and why biogenic amines such as Histamine, Putrescine, Cadaverine or Tyramine can be particularly interesting for sensitive people.

Why the gut is so important for the immune system

The intestinal mucosa is in daily contact with food components, bacteria, metabolic products and other substances from the intestinal lumen. The intestine therefore requires a finely tuned defence and regulatory system.

One important area is the so-called Lamina propria. It lies beneath the intestinal mucosa and contains many immune cells, including plasma cells, lymphocytes, macrophages and other cells of the immune system.

Plasma cells can produce immunoglobulins. Secretory IgA plays a particularly important role in the intestine because it comes into contact with microorganisms and food components on the surface of the mucous membrane.

Lamina propria: Immunoactive layer of the intestinal wall

The lamina propria is one of the most immunologically active areas of the body. This is where the mucous membrane, intestinal flora and immune cells meet.

This area is important because the intestine has to constantly differentiate: Which substances are part of the normal diet? Which bacteria are part of the intestinal flora? And to which signals should the immune system react more strongly?

A diverse and stable Intestinal flora is often considered in connection with the development and regulation of the intestinal immune system. This is not about a direct healing effect, but about the interaction between the microbiome, mucous membrane and immune response.

The four levels of protection in the gut

The intestine has several layers of protection that work together. A distinction is often made between four areas:

• microbial barrier: the intestinal flora and its metabolic activity
• anatomical barrier: Mucosa, intestinal epithelium and mucus layer
• humoral defence: Soluble antibodies such as immunoglobulins
• cellular defence: Immune cells in the intestinal wall

These protective systems are particularly important when dealing with microorganisms and antigenic structures. At the same time, smaller metabolic products, food components or biogenic amines can become relevant in other ways because they are not always treated like classic microbial antigens.

It therefore makes sense to consider gut health not only in terms of bacteria, but also in terms of nutrition, fermentation, storage, digestion, the mucosal environment and individual tolerance.

Local immune stimulation through the intestinal flora

The intestinal flora is in constant contact with the immune system. Components of bacterial cell walls can be immunologically active and send signals to the intestinal immune system.

These components include, among others Peptidoglycan and Lipopolysaccharides, LPS for short. Peptidoglycan is found in bacterial cell walls. LPS is primarily a component of the outer membrane of gram-negative bacteria.

Such bacterial signals are considered in research in connection with immune training, the mucosal environment and the development of the intestinal immune system. However, the balance is crucial: a stable intestinal environment is to be assessed differently than a disturbed barrier or a strong systemic inflammatory reaction.

LPS, intestinal barrier and inflammatory processes

LPS is often discussed in connection with the intestinal barrier, immune response and inflammatory processes. In the intestine, contact with bacterial components is basically normal. It can become problematic if the barrier function is disrupted and large quantities of bacterial components enter areas where they can trigger strong immune reactions.

For this reason, the intestinal barrier is often considered in research in connection with nutrition, intestinal flora, mucous membrane, dietary fibre, inflammatory processes and modern lifestyle.

The most important thing for consumers is that a fibre-conscious diet, sufficient fluids, as few highly processed foods as possible and a varied plant-based diet can create a favourable nutritional environment for the gut.

What are biogenic amines?

Biogenic amines are nitrogen-containing compounds that can be formed by the breakdown or conversion of amino acids. They can occur in food or be formed by microbial processes.

Known biogenic amines are

• Histamine from histidine
• Tyramine from tyrosine
• Putrescine from ornithine or arginine
• Cadaverine from Lysin
• Tryptamine from tryptophan
• Agmatine from arginine

Biogenic amines are not fundamentally „bad”. Some have physiological functions in the body. However, a high intake via food or a reduced individual tolerance can be problematic.

How are biogenic amines formed from amino acids?

Biogenic amines are often produced by microbial decarboxylation of amino acids. In this process, amino acids are chemically converted by microorganisms.

Typical examples are

• Histidine → Histamine
• Lysine → Cadaverine
• Ornithine → Putrescine
• Arginine → agmatine and putrescine
• Tyrosine → Tyramine
• Phenylalanine → Phenylethylamine
• Tryptophan → Tryptamine

Whether biogenic amines are produced in large quantities depends on several factors: Freshness, storage, temperature, pH value, microbial activity, ripening, fermentation and processing.

Histamine, putrescine and cadaverine

Histamine is the best-known biogenic amine. It is often considered in connection with histamine intolerance, matured foods, fermented products, storage and individual tolerance.

Putrescine and cadaverine are also produced by microbial processes. They are primarily discussed in connection with food quality, spoilage, meat ripening, fish quality, fermentation and intestinal flora.

For sensitive people, it is therefore not only the histamine content of a food that is of interest. Freshness, storage, ripening, processing and the entire intestinal flora can also play a role.

Free amino acids and biogenic amines

Free amino acids are already unbound. This can make them more readily available for microbial transformation processes in certain foods or in the digestive tract.

This does not mean that free amino acids are automatically problematic. The decisive factors are quantity, combination, food quality, processing, intestinal flora and individual tolerance.

Free amino acids are used more frequently in modern food and animal feed. This topic is therefore increasingly being discussed in connection with modern nutrition, industrial animal feed, protein products, biogenic amines and digestion.

Biogenic amines in food

Biogenic amines can mainly be produced in foods that have been matured, fermented, stored for a long time or microbially modified. These include, for example:

• Matured cheese
• Salami and other matured meat products
• Fermented foods
• Fish and seafood in unfavourable storage conditions
• Wine and certain alcoholic beverages
• Sauerkraut and other fermented vegetable products
• Soya products such as soya sauce or fermented soya preparations

These foods are not automatically bad. For sensitive people, however, the quantity, combination and personal tolerance can be decisive.

Biogenic amines in animal feed and industrial production

Free amino acids and other starting materials are also used in the animal feed industry and in fermentative production processes. In addition to the desired main product, by-products can also be created.

In modern animal feed production, amino acids such as lysine, methionine or threonine are used to specifically control the amino acid profile. This topic is considered particularly in connection with industrial animal feed, meat quality, intestinal flora and biogenic amines.

It is important to categorise them objectively: not every substance produced by fermentation is automatically problematic. The decisive factors are purity, processing, control, dosage, food quality and the entire food chain.

You can find out more in the article about Industrialised animal feed and meat quality.

Why food quality is so important

Biogenic amines show very well why food quality is not only dependent on nutritional value. Freshness, storage, ripening, hygiene, processing and microbial activity also play a major role.

It is worth taking a closer look at the origin and freshness of meat, fish, fermented products and highly processed foods in particular.

For people with sensitive digestion, histamine intolerance or unclear tolerance, freshly prepared, minimally processed foods can often be easier to assess than long-stored or highly processed products.

What does this mean for intestinal flora and digestion?

No single substance alone is decisive for intestinal flora and digestion. The entire nutritional environment is important: fibre, freshness, variety, liquid, processing, protein intake and individual tolerance.

A fibre-conscious diet can support the intestinal flora in a natural way. Soluble fibres in particular, such as Inulin and pectin are often considered in connection with intestinal flora, fermentation and digestion.

Also Pure apple fibre may be of interest to people who want to make their diet more fibre-conscious.

Fulvicherb Synergy in connection with intestinal flora and nutrition

In this context Fulvicherb Synergy as a liquid formula with fulvic acid, inulin, pectin, arginine, niacinamide, natural unrefined rock salt, sunflower lecithin and other natural ingredients.

The formula combines prebiotic fibres, herbs, micronutrients and natural complexing agents in one product. It is particularly interesting for people who are interested in intestinal flora, digestion, free amino acids, biogenic amines and modern nutrition.

The focus should always be on the overall diet. Fulvicherb Synergy does not replace a balanced lifestyle, but can be used as a complementary liquid formula in a conscious nutritional concept.

Frequently asked questions about the intestinal immune system and biogenic amines

What are biogenic amines?

Biogenic amines are compounds that can be produced by the microbial conversion of amino acids. Well-known examples are histamine, putrescine, cadaverine and tyramine.

What does histamine have to do with biogenic amines?

Histamine is one of the best-known biogenic amines. It is formed from the amino acid histidine and is often considered in connection with histamine intolerance, food ripening, fermentation and individual tolerance.

Which foods contain a lot of biogenic amines?

Biogenic amines can occur primarily in matured, fermented, long-stored or microbially modified foods. These include matured cheese, salami, fermented products, wine, fish in unfavourable storage conditions and certain soy products.

What do free amino acids have to do with biogenic amines?

Free amino acids can be converted into biogenic amines by microbial processes. However, the decisive factors are food quality, storage, processing, microbial activity and individual tolerance.

What role does the intestinal flora play?

The intestinal flora influences the environment in the intestine and is in close contact with the intestinal mucosa and the intestinal immune system. It is often considered in connection with fermentation, digestion and biogenic amines.

Are biogenic amines always dangerous?

No. Biogenic amines are found in food and in the body. High quantities, unfavourable combinations or individual sensitivity can be problematic.

What can you do if you have sensitive digestion?

Fresh food, short storage times, less processed products, sufficient fibre and a conscious selection of fermented or matured foods can be helpful. Medical advice should be sought if symptoms are severe.

Conclusion: consciously categorise intestinal flora, immune system and biogenic amines

The intestinal immune system is in close contact with the intestinal flora, the intestinal mucosa and many components of the daily diet. The lamina propria, plasma cells, immunoglobulins and bacterial signals are part of a complex regulatory system.

Biogenic amines such as histamine, putrescine, cadaverine or tyramine are formed from amino acids through microbial processes. They are considered in the context of food quality, fermentation, storage, intestinal flora, histamine intolerance and sensitive digestion.

If you want to be more conscious about your diet, you should not just look at individual substances, but at the entire nutritional environment: fresh food, good storage, less processed products, sufficient fibre and a stable intestinal flora.