The microbiome

Bacteria have a rather bad reputation: Often they are regarded only as pathogens. In the case of pathogens this reputation is justified. However, humans also live in symbiotic equilibrium with bacteria: They urgently need each other to stay healthy.

Every human being lives in 40 to 100 billion microorganisms such as bacteria, viruses and fungi. Most live in the digestive tract, others on the skin, in skin folds and on mucous membranes. The totality of the genes of these living beings is called the microbiome. In and on our body there are different microbiomes - in the intestine, in the oral cavity, on the skin, in the urinary tract or in the female genital area. The different microbiomes represent closed habitats whose bacterial composition is very different.

The microbiome of the intestine

The largest and most important microbiome is found in the human intestine. It is home to a microbial community of over 1,000 species. This "intestinal microbiome" exceeds human genetic information by a factor of 150 and thus represents the largest bacterial network in the human body. The composition of the intestinal flora varies from person to person. The percentage of different intestinal bacteria is also decisive for intestinal health. Basically, five bacterial strains are distinguished in the intestine: Firmicutes, Bacterioidetes, Proteobacteria, Actinobacter and Verrucomicrobia. Over 99 percent of these bacteria are anerobic, which means they need an oxygen-free environment to survive.

The different intestinal segments are populated by different bacteria. Only a small part of the total bacteria of the intestinal flora lives in the small intestine. Lactobacilli, which produce lactic acid, ensure a stable pH value in the acidic range. If the pH-value tilts, this can lead to the growth of pathogenic germs, especially intestinal fungi.

The large intestine is the most densely populated part of the digestive tract. Billions of bacteria ferment here ballast materials to essential micro nutrients. One of the most important bacterial strains of a healthy intestinal flora here is the group of bifidobacteria. Studies prove that they play an important role in the prevention of irritable bowel syndrome and chronic inflammatory bowel diseases, in the stabilization of cholesterol levels, the alleviation of allergic symptoms, the improvement of skin appearance and also in the prevention of colon cancer. Other important health-promoting bacteria in the colon are lactobacilli such as Lactobacillus rhamnosus, Lactobacillus breve, or Enterococcus durans.

The most important bacteria of the intestinal microbiome

Bacterial strains Bacterial species Frequency
Bacteroidetes Bacteroides vulgatus ++++
Degradation of soluble dietary fibres
Alistipes sp.
Parabacteroides sp.
Prevotella sp.
Firmicutes Faecalibacterium prausnitzill**
Eubacterium rectale**
Eubacterium hallii**
Rominococcus bromii
++ to ++++
++ to +++
+ to +++
+ to ++
Abbau unlöslicher Ballaststoffe
Clostridium clostridioforme
Anaerostipes hadrus
Lachnospiraceae sp.
Roseburia sp**
+ to +++
Actinobacteria Bifidobacterium sp.
Collinsella aerofaciens
++ to +++
+ to +++
Proteobacteria Escherischia coli +
Verrucomicrobia Akkermansia muciniphila*** +

* Carbohydrates
** butyric acid formers
*** Muzin former

Source: The intestinal microbiom, biovis Diagnostics, Fachinformation 2016

The microbiome of the oral cavity

The mucous membrane of the oral cavity, the nasal cavities, the throat and esophagus, the gums and the teeth are densely populated by microorganisms. Probiotics prevent the entry of pathogenic bacteria, fungi and viruses through the mouth and nose. Probiotics do this by producing certain acids and antibiotics that either specifically kill these types of invaders or create an environment in which the invaders do not feel comfortable. These so-called "oral probiotics" very effectively circulate in the mucous membrane of the upper respiratory tract, teeth and gums.

It becomes problematic if we consume too much sugar. Probiotics need complex oligosaccharides such as inulin or fructooligosaccharides as food and not simple sugars such as glucose and sucrose as in household sugar. Pathogenic germs, on the other hand, love simple sugars and multiply explosively. They secrete certain acids that damage teeth and inflame gums and oral mucosa.

The good, health-promoting bacteria, which protect the mouth area, stand against it. They displace harmful microorganisms and thus prevent tooth decay, periodontosis and infections of the oral cavity and upper respiratory tract.

Studies have found certain bacterial strains that restore balance to an unbalanced oral flora and provide targeted protection against infections. The aim is to create a healthy environment for prophylaxis and support of natural defence. Proven bacterial strains are e.g. Lactobacillis rhamnosus, Lactobacillis reuteri, Lactobacillis sakei, Lactobacillis plantarum, Lactobacillis curvatus, Lactobacillis salivarius, Bifidobacterium infantis, Bifidobacterium animalis and Streptococcus thermophilus.

What are probiotics?

The term "probiotics" comes from Greek and means as much as "for life." Probiotics are living bacteria that are ingested and have special health-promoting properties for the human body. The World Health Organization (WHO) defines "probiotics" as living microorganisms that give the host (i.e. the intestine) a health advantage if they are ingested in sufficient quantities. Humans and microbes are a functional unit. And probiotics offer opportunities for the prevention and treatment of various diseases.

Probiotic cultures are offered in foods, as food supplements or as medicines. Probiotic foods include various dairy products such as yogurt, kefir or drinking yogurt. These include primarily representatives of lactic acid bacteria such as bifidobacteria or various forms of lactobacilli.

The probiotic drugs or dietary supplements are offered in the form of capsules, tablets or powder. The decisive difference between foods enriched with bacteria and food supplements, however, lies in the number of bacteria they contain. A therapeutic effect can only be achieved with a correspondingly high number of colonies of at least 3 to 10 billion bacteria for the intestine and 1 billion for the oral cavity. The key, especially in probiotics for the intestine, is how many bacteria actually arrive alive at their destination.

Benefits of probiotics

The tasks of probiotics are manifold. Accordingly, the benefit is great if the respective microbiome is healthy and in balance.

Fighter against pathogens
In us the war rages daily, between good bacteria and pathogenic germs. Only if there are enough probiotics, i.e. good bacteria, can the disease-causing bacteria, viruses and fungi be kept in check and we remain healthy.

Bowel cleansing
The daily supply of many active intestinal bacteria, especially bifidobacteria and lactobacilli, free the intestinal villi from rotting and fermenting residues.

Protection of the intestinal mucous membranes
Probiotics form a living protective shield on the intestinal mucosa that prevents harmful substances from entering the body and blood.

Stimulation of mucin production
Mucin is a mucus that forms a protective layer on the intestinal mucosa that separates the inside of the body from the intestinal contents. This prevents a "leaky gut syndrome" from developing into a "perforated intestine" through which allergy-inducing substances, toxins and pathogens could enter the body.

Degradation of metabolic toxins
During metabolic processes, harmful substances are also produced in our body, which are rendered harmless by probiotics and transported out of the body with the stool.

Balance of the immune system
Some bacterial species, such as lactococcus and enterococcus, are responsible for the production of regulating immune cells. An immune system is healthy when it is in balance, i.e. it is strong in defence but does not overreact. This is particularly important in the prevention of allergies such as neurodermatitis and asthma, but also of autoimmune diseases such as multiple sclerosis.

Support of the absorption of enzymes
Especially the liver, the gall bladder and the pancreas are supported by the good bacteria in your metabolic work.

Production of nutrients and vital substances
Not all the substances we need can be ingested with food. Our intestinal bacteria first have to assemble some essential components from various components.

The new generation of indication-based probiotics

Research into the human microbiome has opened up completely new possibilities for the prevention and treatment of a wide variety of diseases and complaints. Only these new research results have made us aware of the enormous influence that a microbial imbalance has on our health. For different clinical circumstances, certain bacterial strains were found that worked on healing and prophylaxis.

Examples of indication-related probiotic treatment

  • Susceptibility to infections
  • Colds
  • Periodontal disease
  • Tooth decay
  • Respiratory infections
  • Allergies
  • Obesity
  • Insulin resistance
  • Irritable bowel syndrome
  • Leaky Gut Syndrome, the "permeable" intestine
  • Inflammatory bowel diseases
  • Elevated cholesterol level
  • Osteoporosis
  • Chronic urinary tract infections
  • Infections of the female vagina
  • Skin diseases


Quality criteria of probiotics

The quality of probiotics is determined by the following criteria:

  • Evidence of the efficacy of the bacterial strains used for certain indications.
  • Evidence of the number of surviving bacteria at the end of shelf life.
  • The bacterial count at the end of the shelf life should be at least 1 billion germs.
  • Number of surviving bacteria at destination.
  • This is particularly important with probiotics that are swallowed, because they must survive for hours the passage through the stomach with its stomach acid and through the duodenum with bile acid and pancreatic secretion to their destination, the large intestine.
  • Not all bacterial strains get along well, but can compete with each other. Therefore, the compatibility and efficiency of mixed bacterial preparations must be proven by tests.
  • All bacterial strains used must be safe and it must be proven that there are no side effects to human use, even if taken over a long period of time.

Determination of the intestinal flora

Before taking intestinal bacteria, it is advisable to examine a stool sample. Such tests are carried out by the following laboratories, for example:

Laboratory Dres. Hauss

Biovis Diagnostics

All-immune Diagnostics AG