Does swallowing a lot of saliva while reciting the Quran in the mosque invalidate the fast of a fasting person in Ramadan?

Swallowing saliva does not invalidate the fast, even if it is abundant. As for thick phlegm (sputum), it is not permissible to swallow it because it is repulsive and may carry diseases, and it must be spat out. However, swallowing it does not break the fast if it does not exit the mouth, because it is not considered eating or drinking.