Bacteria in the intestines - The human microbiome

And how to influence it

The human digestive tract contains an extremely large quantity of microorganisms including bacteria, which play a dominant role and live in a community with the human organism. According to expert estimations, at least 1000 - 1200 species of bacteria can be found in the human gut. Many of these bacteria have never been cultivated and with an absolute value of at least 100 trillion bacteria, the largest amount of this proportion can be found in the colon. These microorganisms are known as "microbiota" or also partially referred to as "gut flora". These bacteria act on the permeability of the intestine, help with the absorption of nutrients and vitamins, process carbohydrates by fermentation, affect the bile fluid and certain hormones, and regulate or resolve processes of the immune system. The emergence and maturation of our immune system is influenced through this important organ (note: the more "dirt" exposure in childhood is therefore likely to be a great privilege!).

The composition of intestinal bacteria can be changed by various factors such as nutrition/diet or medication, particularly pro- and antibiotics. Various other factors such as age, (competitive) sports, smoking, type of birth (vaginal vs. caesarean) or resolved infections with parasites (worms) also appear to play a role. An imbalance in the human microbiome (dysbiosis) as triggered by antibiotic therapies can cause gastrointestinal tract infections and the development of autoimmune diseases as well as inflammation, cancer, metabolic, neurological and psychiatric diseases. Among the latter, a dysbiosis has been detected in chronic fatigue syndrome and depression. Therefore, some foods could be used to antagonise these diseases.

Influencing the microbiome - probiotics, prebiotics and synbiotics

A balanced diet with a high fruit and vegetable content acts favourably on the human microbiome. "Prebiotics" are non-digestible food constituents that selectively stimulate the growth and/or activity of one or more bacterial types in the colon and thus, optimally affect the microbiome. This includes many types of vegetables but also lactose (milk sugar). However, the consumption of many prebiotics can also result in experiencing symptoms such as bloating; a temporary reduction of these foods in the so-called FODMAP diet can relieve symptoms in patients with irritable bowel syndrome.

In certain situations, the use of "probiotics" (e.g. lactic acid bacteria, yeasts and others) can be useful after experiencing infectious diarrheal diseases. These "good" bacteria displace the harmful bacteria to restore the disturbed balance in the microbiome after infection. When the intake of these bacteria is stopped, they are quickly displaced again by other intestinal bacteria.

The combination of prebiotics and probiotics is called synbiotics and should combine the positive properties of prebiotics and probiotics and have a positive effect on the microbiome. However, clear scientific evidence of the effect of these products do not currently exist.

Influencing the microbiome - stool transplantation

The unsavoury notion of using stool from another person is actually a very old known therapy. In ancient China during the 4th century Dongjin dynasty, Ge Hong already described the internal application of stool in an emergency medical textbook, which was made more palatable to patients under the name "yellow soup". Instinctively, newly-born foals, for example, eat the stool of their parents to develop and enable the microbiome in their gut.

Das intestinale Mikrobiom kann heute durch eine «fäkale Mikrobiotatransplantation» (FMT, oder Stuhltransplantation) effektiv manipuliert werden. Die FMT kann sicher und effektiv in der Behandlung von wiederholten Infektionen mit «Clostridium difficile» angewendet werden. Bei widerholten und schweren Infektionen trotz antibiotischer Therapie organisieren wir diese Therapie in Kooperation mit dem Stadtspital Triemli für Sie.

Nowadays, the intestinal microbiome can be effectively manipulated with a "faecal microbiota transplantation" ([FMT] also known as a stool transplant). A FMT can be safely and effectively applied in the treatment of repeated infections with Clostridium difficile. For repeated and severe infections resistant to antibiotic therapy, we can organize this FMT therapy for you in cooperation with the Triemli hospital.

Although possible therapies for other diseases (e.g. irritable bowel syndrome, chronic inflammatory diseases, metabolic disorders and neuropsychiatric diseases such as multiple sclerosis or autism) are emerging, undertaking any of them outside the framework of a clinical trial is currently not recommended. We are happy to clarify this with you during a consultation.

Refer to the film with contributions from our practice in the NZZ format: "News from the gut"

«Neues vom Darm»



For more information, read our publication in the Swiss Medical Forum (Stool transplantation - an old and new therapeutic approach) or contact us.

(Stuhltransplantation – Ein alter und neuer Therapieansatz) or kontaktieren Sie uns.