Intestinal microbiota

Aspergilli — is a genus of mold fungi that includes many species (for example, Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus), some of which are pathogens for humans. Their ability to cause diseases (aspergilloses) is associated with a weakened immune system, disruption of intestinal microflora, and excessive growth of colonies in unfavorable conditions.

Pathogenicity of Aspergilli

Immunocompromised conditions. Aspergilli are particularly dangerous for people with weakened immune systems (HIV, chemotherapy, organ transplants).

Aspergillosis — is a systemic disease in which the fungus can affect the lungs (invasive aspergillosis), sinuses, skin, and even the brain.

Mycotoxins. Some species (especially A. flavus) produce aflatoxins — potent hepatotoxins and carcinogens that can accumulate in the liver and provoke malignant processes.

Aspergilli and Intestinal Microflora

Normally, aspergilli are not the main inhabitants of the intestinal microbiota. They may be present transitively (for example, through food), but they are not conditionally permanent symbionts like Candida or E. coli.

However, with disrupted acidity, antibiotic use, or immunodeficiency, fungi can colonize the gastrointestinal mucosa and cause local inflammation, wall permeability, and allergic reactions.

Nutrient Medium: Proteins and Carbohydrates

Aspergilli are saprobes that grow well on organic substrates. Their enzymatic apparatus is capable of breaking down:

• Polysaccharides (starch, cellulose) using amylase;
• Proteins using proteases;
• Cell walls of plants (cellulase, hemicellulase).

Therefore, protein and carbohydrate food is an excellent medium for the growth of these fungi.

Aspergilli and Fats

Fats are indeed less suitable for the growth of aspergilli because:

• Fungi lack effective enzymes for mass breakdown of saturated fats;
• The fatty medium limits access to oxygen and moisture, which are necessary for aerobic fungi;
• Some fatty acids (especially short-chain and medium-chain, like those in coconut oil) have antifungal properties.

Fats do not "kill" aspergilli directly. This is rather an unfavorable environment for the active growth of fungi, rather than a means of destruction.

However, fats, especially saturated ones and those containing antimicrobial components, can suppress growth and reduce pathogenicity of aspergilli due to:

• changing the environment;
• direct membrane-toxic action of fatty acids;
• enhancing the protective functions of the gastrointestinal tract.

Myelin sheaths play a key role in the speed of nerve impulse conduction, and their condition is directly related to the body's response to dangerous stimuli, including hot objects.

Myelin — is a special layer composed mainly of lipids (about 70–80%) and proteins (20–30%), which forms a kind of "insulation" around the axons of nerve cells. This sheath acts as an electrical insulator, accelerating the transmission of impulses along nerve fibers by tens and even hundreds of times.

With healthy myelin sheaths, the transmission of signals along motor and sensory fibers can reach speeds of 80–120 m/s. This means that information about touching a hot object reaches the spinal cord and brain almost instantly, activating the reflex withdrawal of the hand even before the conscious sensation of pain.

Damage to Myelin Sheaths

Myelin sheaths undergo constant micro-damage during the functioning of the nervous system and require regular restoration.

When myelin sheaths are damaged (for example, due to a deficiency of fats in the diet, a lack of B vitamins, especially B12, or due to chronic inflammatory and demyelinating processes), the speed of impulse transmission decreases.

In the absence or significant damage to the myelin sheath, the speed of impulse conduction drops to 0.5–2 m/s (an average of about 1 m/s). This leads to a delayed reaction: the brain receives the signal with a delay, and a person physically has time to get burned more severely.

Examples of conditions where the speed drops to ~1 m/s:

• Multiple sclerosis (demyelination of the CNS)
• Polyneuropathies (including diabetic)
• Deficiency of vitamin B12 or copper (necessary for myelin synthesis)
• Chronic deficiency of fats and cholesterol in the diet
• Deficiency of plasmalogens

What are Plasmalogens and Why are They Needed for Myelin

Plasmalogens are partially synthesized by the body itself, but their full formation requires metabolites from beneficial gut bacteria. Bifidobacteria and some strains of Lactobacillus are involved in the production of plasmalogen precursors.

In dysbiosis (the predominance of pathogenic flora), the production of these metabolites sharply decreases.

As a result:

• The synthesis of plasmalogens decreases.
• Myelin sheaths are renewed less effectively and become more fragile.
• The speed of impulse conduction decreases → higher risk of burns, numbness, and paresthesias.

The intestine is the largest immune organ in the human body — it contains about 70–80% of all immune cells. This is explained by the fact that the intestine is constantly in contact with a vast number of antigens: from food, bacteria, viruses to metabolic products.

To control this flow, a powerful immune system, called gut-associated lymphoid tissue (GALT), is developed in the intestinal mucosa.

Why is the microbiome important for immunity?

The gut microbiome — is a collection of trillions of microorganisms, including bacteria, viruses, and fungi, that live in symbiosis with humans. It plays a key role in training and modulating the immune system. Below are the main mechanisms:

Training the immune system. In newborns, the immune system is still "tuned randomly." As the body matures, it learns to distinguish pathogens from harmless antigens, and the microbiome is an important "trainer." Beneficial bacteria stimulate the production of regulatory T cells, which help prevent autoimmune reactions.

Maintaining the barrier function of the intestine. The microbiota stimulates the production of mucin, immunoglobulin A (IgA), and antimicrobial peptides. This strengthens the intestinal mucosa and prevents pathogens from entering the bloodstream.

Regulating inflammation. The diversity of the microbiome contributes to the balance between pro-inflammatory and anti-inflammatory responses. For example, the bacteria Faecalibacterium prausnitzii produce butyrate — a short-chain fatty acid that suppresses inflammation.

Competing with pathogens. The richer the microbiome, the less "food" and space there is for pathogens. This is called colonization resistance: beneficial microbes prevent harmful bacteria from establishing themselves.

What happens when microbiome diversity decreases?

• Increased intestinal permeability (leaky gut syndrome)
• Activation of inflammatory pathways (via TLR — toll-like receptors)
• Disruption of food tolerance
• Increased risk of autoimmune and allergic diseases (Crohn's disease, type 1 diabetes, asthma, etc.)

How to maintain a diverse microbiome?

• Diverse diet, especially rich in fiber (vegetables, greens, legumes)
• Fermented products (kefir, yogurt, sauerkraut)
• Limiting antibiotics
• Spending time in nature, contact with animals
• Minimizing ultra-processed foods

Thus, a diverse gut microbiome — is not just "beneficial bacteria," but a complete immune ecosystem on which human health depends.