Gut health and the microbiome: what influences our gut in everyday life

This topic was selected in our BodyWision Club poll as the next subject for the blog.

The microbiome: a community with many roles

Our gut is home to bacteria, fungi, viruses and other microorganisms. The organisms themselves are called the microbiota. Depending on the definition, the term microbiome also includes their genes and surrounding environment.

Gut microorganisms help process food components that our own digestive enzymes cannot fully break down. This produces metabolites, including certain short-chain fatty acids that play a role in the intestinal lining. Gut microbes also interact with the immune system. Gut health, however, involves more than the composition of this community. [1]

Why there is no perfect microbiome profile

Microbiome composition differs between people. Diet, age, illness and medicines can influence it. Antibiotics, in particular, can also affect bacteria that normally live in the gut.

An unusual pattern is not a diagnosis on its own. Differences observed between people with and without a disease initially show an association; they do not automatically prove that gut microbes caused the condition. Universally applicable reference ranges for an “optimal” personal microbiome are not currently established. [2]

Fibre: varied sources and gradual changes

Vegetables, fruit, pulses, whole grains, nuts and seeds provide fibre. Different fibre structures are used differently by gut microorganisms. Controlled studies have also demonstrated that different fibres can produce different microbial responses. This does not yet justify a personal dietary plan based solely on a microbiome profile. [3]

For adults, the WHO recommends at least 25 grams of naturally occurring fibre daily. The German Nutrition Society uses at least 30 grams as a reference value. These are general dietary recommendations, not treatment targets for specific gut symptoms. [4]

Small changes can help: choosing whole grains more often, adding a tolerated portion of pulses or varying vegetables and fruit. Increase fibre gradually and drink enough fluids. A sudden change may worsen bloating. Individual tolerance matters, and existing bowel conditions may require tailored advice. [5]

Fermented does not automatically mean probiotic

Fermentation involves microorganisms transforming food. Examples include yoghurt, kefir, sauerkraut and kimchi. Whether live microorganisms remain in the finished food depends partly on processing. Heating can kill them.

Fermented foods can add variety to a diet. The label alone does not demonstrate a particular health effect: that requires appropriate studies of the food or its microorganisms. [6]

Probiotics: the specific use matters

Probiotics are live microorganisms that provide a demonstrated health benefit when consumed in adequate amounts. The studied strain or combination, dose and intended use matter. Findings for one preparation cannot automatically be transferred to another. [7]

Some uses show evidence of benefit, while many broad claims remain insufficiently supported. This does not establish a general recommendation to take probiotics preventively. People with serious illness or a weakened immune system should discuss their use with a clinician first. [8]

What commercial microbiome tests can and cannot tell you

These tests usually describe microorganisms in a stool sample. Results also depend on timing, sample collection and analysis methods. They are not a comprehensive assessment of gut health.

An international expert panel considers the evidence insufficient for widespread routine use. Dietary changes or treatment should not be based on a commercial microbiome report alone. These tests differ from clinician-requested stool tests for specific pathogens or signs of inflammation. [9]

Understanding symptoms in context

Bloating, abdominal pain, diarrhoea and constipation can have different causes. Persistent or worsening symptoms merit medical assessment. Blood in the stool, unexplained weight loss or fever should be assessed promptly. [10]

A brief record can help prepare for an appointment: When do symptoms occur? How long have they been present? Which medicines do you take, and what has recently changed? An observation is a clue, not proof of a cause.

A manageable starting point is to eat a varied diet, introduce changes gradually and pay attention to tolerance. When symptoms occur, medical assessment should consider the full context.

Sources last checked on 25 September 2026.