He notices the taste of toothpaste when he is praying. What should he do about food remnants that remain between his teeth? Is his prayer invalidated by swallowing his saliva?
Question

                before going to salat , i usually brush my teeth , but the toothpaste has a very strong taste that remains in my mouth , so i feel it during the prayer is my prayer valid? if yes is it invalid if i swallow my saliva? does the same rule apply to food also?.
Praise be to Allah.
    Firstly: 

    Swallowing saliva whilst praying does not affect the prayer, 
    because it is not food or drink and it does not come under the heading of 
    food or drink in any way. If a person is fasting, his fast is not 
    invalidated by swallowing his saliva, so it is more apt that the prayer 
    should not be invalidated by that. 

    See the answer to question no.
    144970 and
    12597 

    Secondly: 

    If a person who is praying swallows remnants of food that are 
    left between the teeth, that does not invalidate the prayer, if it is 
    something small that flows with the saliva, because it is difficult to avoid 
    that. 

    Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) was 
    asked: What is the ruling on remnants of food between the teeth whilst 
    praying? 

    He replied: With regard to remnants of food between the 
    teeth, there is nothing with them remaining between the teeth, even if one 
    prays, but if anything breaks off of it, he should not swallow it. Sometimes 
    some food gets stuck between the teeth, then after a while it comes out from 
    between the teeth or he may dislodge it with his tongue and it comes out. We 
    say: There is nothing wrong with that, but he should not swallow it. End 
    quote. 

    Al-Bahooti (may Allah have mercy on him) said: There is 
    nothing wrong with swallowing remnants of food that are left in the month, 
    without chewing, or swallowing remnants of food that are left between the 
    teeth, without chewing, that are small and will flow with the saliva, 
    because that is not called food. That which does not flow with the saliva, 
    rather it has substance, invalidates the prayer if it is swallowed… End 
    quote from Kashshaaf al-Qinaa‘, 1/339 

    It says in al-Mawsoo‘ah al-Fiqhyyah (27/124): The 
    fuqaha’ are unanimously agreed that the prayer is invalidated by eating and 
    drinking in general, but they made an exception with regard to that which is 
    caught between the teeth and is less than the size of a chickpea. This does 
    not invalidate the prayer if it is swallowed, but they stated clearly that 
    the prayer is invalidated by chewing if it is a large amount. End quote. 

    Thirdly: 

    With regard to the smell and flavour of the toothpaste that 
    remains in the mouth, that does not affect the validity of the prayer, 
    because it is not regarded as food or drink. 

    And Allah knows best.