Probably not except , the small guards that fit over the down pipes see below.
The down pipe leaf guards should be fitted to all down pipes that disappear into the ground.
Should the pipework get blocked it could be very expensive to have it cleared. If the pipework leads to a soakaway it could involve costly excavations.
The larger leaf guards that cover the whole length of the gutter may help delay the inevitable. but eventually they will need cleaning.
The only way to clean a gutter with a leaf guard is to remove the leaf guard, this is likely to increase your bill for cleaning the gutter. the cost of removing the leaf guard may well negate any savings from having the leaf guard fitted.
The solution is to have your gutters cleaned regular by a professional gutter maintenance company. How much should it cost to have my gutters cleaned?
Kingfisher Windows and Gutters