It is normal that there will be some sediment at the bottom of Yakult. This precipitate is a fat-free milk solid, and its main components are vitamins, protein, calcium and other nutrients. It may also be because Yakult used some additives in the production process, such as pigments. These substances may not be completely dissolved in the production process, which eventually leads to the formation of black spots at the bottom of the bottle.
The above information is for reference only. If you have other questions, please consult a professional.