A journey to the centre of the gut

Focus on gut health

The gut is a complex organ, but what at first glance looks like chaos is in fact a brilliant system. The bacteria in the intestine have a major impact on health. If you are tempted to think: ‘Yuck, bacteria!’ please rest assured: nothing works without bacteria! From the moment we are born, they colonise our body, inside and out. This is a good thing; indeed it is essential for survival. We live in a symbiotic balance with bacteria, and really need them for our health. The majority of these ‘health custodians’ live in the gut, and the greater their diversity, the better for us.

In order for the intestines to correctly fulfil their role as nutrient providers and essential components of the immune system, they need good bacterial colonisation and a healthy mucous membrane. When these factors are compromised, pathogens find it easier to spread, leading to an over-burdening of the immune system and increased susceptibility to infection.

The arrival of bacteria

Before birth, the human body is almost germ-free. Bacterial colonisation begins during the birth process, because this is when contact with the outside world begins. The bacteria’s settlement into the body is influenced by the type of delivery (natural or by caesarean section), an infant’s diet, the level of hygiene in the environment, and the use of medication, including antibiotics. Colonisation in adults varies widely and depends on a range of factors such as age, location, health, stress, use of laxatives, socio-economic status and – most importantly – diet.

If you’ve ever been prescribed antibiotics, you may have experienced one of the typical side effects: diarrhoea. This is because this type of medication is disruptive to bacterial colonisation. Antibiotics cause a long-term decline in gut bacteria biodiversity. In the past, it was thought that things quickly returned to normal once a patient stopped taking antibiotics, but we now know that they bring about long-lasting changes to bacterial colonisation and can even lead to severe pathogenic germ growth.

Bacteria form a dense turf on the intestinal mucosa, which prevents pathogens from docking onto or penetrating it. Unhealthy eating habits, stress, infections and medication – especially antibiotics and laxatives – all have negative effects on the gut. If the intestinal environment – and thus the balance of bacterial strains – is upset, a whole raft of health problems can ensue, including bloating, constipation, diarrhoea, food intolerances, allergies, chronic inflammation and immune system disorders. Like messenger substances and hormones, bacteria can also affect the development and function of the central nervous system. This special form of communication between gut and brain is also known as the gut-brain axis. The identification of bacterial strains and their relationships in the gut allows us to study disease processes and develop appropriate therapeutic measures.

A molecular genetic faecal test provides the data that helps decide on a therapy that will turn the cacophony of gut flora into a harmonious symphony of good health. It affords valuable information on the current intestinal condition, forming the basis for a therapeutic way forward. This kind of analysis reveals microbial imbalances, provides a picture of microbial biodiversity, and gives us many additional data to help us assess the intestinal environment. In addition, this test helps us assess the intestinal mucosa’s condition and digestive performance, as well as the immune situation within the gut.

As a rule, the greater the gut’s bacterial diversity, the better. There is no such thing as a positive or negative germ – conditions and diversity are the key, as are the microbiome’s actual metabolic activities. Current studies show that healthy ageing is related to a high level of bacterial biodiversity in the intestines. Changing the diet and supplementing with live microorganisms can alter the gut’s bacterial colonisation and have a positive effect on health. Increasing the amount of fibre in the diet with vegetables, whole grains and other prebiotics can modify the microbiome.

How can we know that our intestinal mucosa is healthy and has a sufficiently diverse bacterial population? When it isn’t, it is possible for problems to arise that are not merely uncomfortable but can be extremely painful or even fatal.

  • A recent study has shown that inflammatory bowel disease, irritable bowel syndrome, and diverticulosis are indications of a microbiotal disorder whereby there has been change to both the quantity and composition of the bacteria. Bacteria have a major part to play, especially in treating irritable bowel syndrome, in the form of probiotics.
  • Studies have shown that bacteria in overweight people are super-efficient at extracting energy from food. The ratio of two major bacteria groups determines how many calories are obtained from food and absorbed by the body. Dietary changes combined with pre and probiotics can sustainably affect this ratio.
  • Bacterial metabolic products such as hydrogen sulphide may play a role in the development of diseases including colorectal cancer. Here too, risks can be reduced with probiotics.

Other conditions and disorders that can be related to the microbiome include:

  • Allergies and food intolerances. 
  • Heightened susceptibility to infection.
  • Neurological and psychiatric disorders such as depression, Parkinson’s disease, migraines, autism and various types of dementia.
  • Chronic inflammatory diseases, e.g. arthritis. 
  • Diabetes/metabolic syndrome.

Microbiome transfer is a treatment that first emerged in the 1950s. The method, which continues to be developed and refined, is used very rarely – and then only when particular indications are present. However, its importance is growing. Also known as faecal transplantation, the aim is to enrich and support the intestinal flora of a person who is unwell with that of a healthy individual. This should consist of the widest possible variety of useful microorganisms to prevent pathogenic bacteria from spreading and causing further damage. Donors are carefully screened and need to be in perfect health with a clear family history. Microbiome transfers are either performed by nasogastric tube or by colonoscopy.

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