wie viel ballaststoffe hat eine banane — what are common causes?

A medium banana (about 120 g) contains roughly 3 g of fiber, primarily pectin and resistant starch. The exact amount varies with ripeness: green bananas have more resistant starch, while ripe ones have more soluble fiber. The second part of the question, 'what are common causes?', is ambiguous without additional context – it could refer to common causes of low fiber intake, digestive issues, or something else entirely. The provided context (VDR gene, DNA tests) does not address bananas or fiber. Therefore, this answer relies on general nutritional knowledge, not the given sources. The evidence is rated as unclear because no relevant studies or guidelines are present in the context. Clarification of the intended meaning would allow a more precise response.