Intestinal Dysbiosis: What It Is, Causes, and the Controversial Diagnosis

The reader often encounters the word "dysbiosis" in the conclusion of a stool test, although there is no separate diagnosis with this name in the international classification of diseases. Below is what this term means, which changes in the microflora are described in guidelines, and why some doctors consider it a consequence of other conditions rather than an independent disease.

What intestinal dysbacteriosis and dysbiosis are

Dysbacteriosis is defined as a state of microbial imbalance on or inside the body. It is not a disease in itself, but it can be a consequence of a disease or an intervention: diseases of the digestive organs, immunodeficiency states, metabolic disorders, medicinal effects, intestinal infections, helminths, stress. The reverse relationship has also been described: a decrease in the protective functions of the normal microflora may contribute to the development of other diseases.

A broader term is dysbiosis: a disruption of the interaction between the body, its microflora (not only bacteria but also fungi and protozoa), and the environment. In Russian-language literature, the historically established "dysbacteriosis" is used more often, although "dysbiosis" is more accurate. In a 2003 order of the Ministry of Health, dysbacteriosis was defined as a clinical and laboratory syndrome associated with a change in the qualitative and/or quantitative composition of the intestinal microflora.

Intestinal microflora: which bacteria are normal

In an adult, the intestinal microflora contains more than five hundred varieties of microorganisms, and their distribution depends on the section. The proximal parts of the small intestine contain on average 10²–10⁴ colony-forming units, the distal parts 10⁵–10⁹; the microflora of the colon is represented mainly by anaerobes in quantities up to 10¹². The total weight of this microflora is over 2.5 kg, about 10¹⁴ colony-forming units.

Causes of dysbacteriosis

Factors are divided into exogenous and endogenous. Mild temporary fluctuations in the number of individual microorganisms, as a rule, resolve on their own: dysbacteriosis may be present for a long time or occur periodically and does not in all cases have clinical manifestations.

• Medicinal effects, including abuse of laxatives and choleretic agents.
• Intestinal infections and helminths.
• Inflammatory and functional diseases of the digestive organs, oncological diseases.
• Metabolic diseases (diabetes mellitus), immunodeficiency states, hypoxia.
• Unhealthy lifestyle, inadequate nutrition, stress, early childhood and old age.

Bacteria in stool: what the test shows

In a day, a person excretes about 17 trillion microbes; they make up to 30% of the dry mass of stool.

Why the diagnosis of "dysbacteriosis" is considered controversial

The International Classification of Diseases, 10th revision, has no heading for "intestinal dysbacteriosis"; the term is also not mentioned in the Russian regulatory document on standards for the diagnosis and treatment of diseases of the digestive organs. Many doctors, especially abroad, instead indicate specific conditions: small intestinal bacterial overgrowth syndrome, antibiotic-associated diarrhea, pseudomembranous colitis. The division of dysbacteriosis into stages is described as conventional.

Probiotics are often associated with this diagnosis. British patient guidance states: there is some evidence that they alleviate certain symptoms of irritable bowel syndrome, but there is little evidence for many claims; probiotics are classified as food products rather than medicines. Some evidence-based medicine doctors consider probiotics ineffective for microbial imbalance: microorganisms from outside are rejected by the body's own microflora.

When to see a doctor

If cramps, bloating, or changes in stool persist, a doctor determines their cause. Irritable bowel syndrome does not damage the intestine but causes pronounced discomfort and is more common in people under 45. In chronic disease or weakened immunity, taking probiotic supplements is discussed with a doctor in advance.

Dysbacteriosis by itself is not a reason to call an ambulance; 103/112 — for a sudden sharp deterioration in condition that threatens life.

This material is for reference: it describes terms and guideline data and does not replace consultation with a doctor.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer