Intestinal microflora: what it is and how it relates to the microbiome

The terms "microflora", "microbiota" and "intestinal microbiome" are often used interchangeably, although there is a difference between them. Below is a reference explanation of what these concepts mean, what functions the microflora performs, and what is meant by its disturbance.

What is intestinal microflora

Microflora usually refers to the collection of microorganisms inhabiting the intestine. The human microbiome includes bacteria, archaea, fungi, protists and viruses; some of them coexist with humans without causing harm (commensal), while some are in mutually beneficial (mutualistic) relationships. Normal microbiota is sometimes considered to be that which is present under ordinary circumstances and does not cause disease.

Microflora, microbiota and microbiome: what is the difference

The word "flora" historically refers to plants, so in technical literature the term "microflora" is considered imprecise; it is more correct to say "microbiota" — the collection of organisms in a specific ecosystem. At the same time, both terms continue to be used. "Microbiome" denotes all the microbes inhabiting the body, including the skin, mucous membranes and gastrointestinal tract, and in the context of genomics — the collection of their genomes.

What is known about the role of microflora

Certain microorganisms perform tasks that are beneficial to humans, although the role of most of them remains not fully understood. The composition of the intestinal microbiome varies greatly and is unique to each person. As part of the Human Microbiome Project, more than 5,000 samples were collected from different body sites in 242 healthy volunteers; researchers described a complex ecosystem comprising more than 10,000 species of microorganisms.

What intestinal imbalance and disturbed microflora mean

Disturbed microflora usually refers to a change in the natural balance of bacteria in the stomach and intestines. Probiotics — live bacteria and yeasts — are considered a means that may help restore such balance. However, there is little evidence to support many claims about the benefits of probiotics; there are some data that they may relieve certain symptoms of irritable bowel syndrome. Probiotics are classified as food rather than medicines, so it is not always known whether a product contains the stated bacteria, whether there are enough of them, and whether they survive the journey to the intestine.

What affects the composition of microflora

The natural balance of bacteria in the intestine can be disturbed by illness or treatment. Different types of probiotics may act differently on the body, and little is known about which of them are better. It is noted separately that there is likely a big difference between pharmaceutical-grade probiotics that have shown results in clinical trials and store-bought yogurts and supplements.

When to see a doctor

You should see a doctor if there is blood in the stool, a change in bowel habits, severe abdominal pain, unintentional weight loss, or heartburn that is not relieved by antacids. If you have an existing condition or weakened immunity, it is recommended to discuss this with a doctor before taking probiotic supplements. The doctor assesses the complaints and, if necessary, orders examinations, such as stool tests or instrumental studies of the intestine.

• Blood in the stool
• Change in bowel habits
• Severe abdominal pain
• Unintentional weight loss
• Heartburn not relieved by antacids

Disturbed microflora on its own is not a reason to call an ambulance; 103/112 — for a life-threatening condition when a person's condition deteriorates sharply.

This material is for reference: it explains terms and does not replace a doctor's consultation.

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