Nutrition expert Uwe Knop: Losing weight through diet and exercise: The surprising truth about our gut

An estimated 100 trillion microorganisms belonging to more than 500 different species live in the human intestine .

These are primarily bacteria. There are also fungi, viruses, and archaea. Bacteria belong to a few main groups (phyla), the most important of which are Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. Researching the gut microbiome and deriving clear recommendations is therefore extremely difficult for several reasons:

1. Individual diversity and complexity

Every person has a unique microbiome, like a fingerprint. It consists of millions of microorganisms (bacteria, viruses, fungi, archaea), whose composition and interactions are highly complex and entirely individual. This makes it difficult to define a single "healthy" microbiome or to derive universally applicable recommendations.

2. Cause and effect

It's often unclear whether altered intestinal flora is the cause or the consequence of a disease. While studies show correlations between certain bacteria and diseases such as diabetes or inflammatory bowel disease, the causal relationship still needs to be investigated in more detail. Keyword: correlation or causation?