wie viel stuhl für stuhlprobe — what does this mean exactly?

The question asks about the required amount of stool for a stool sample, such as for a MyBody-X microbiome test. Typically, a small amount is sufficient – about the size of a hazelnut to a walnut, i.e., 1–2 grams. Most commercial tests provide a collection tube with buffer solution that only needs a minimal fill. It is important that the sample is not contaminated with urine or water. Exact instructions are included in the kit. From a scientific perspective, the sample quantity is usually not critical for reliable DNA extraction and microbiome analysis, as long as it is sufficient. Too much stool can overwhelm the buffer and impair analysis. The evidence is based on laboratory practice, not controlled studies. Caveat: In case of diarrhea or very soft stool, sampling can be difficult; follow the manufacturer's instructions carefully.