"combatted by" is a grammatically correct phrase and can be used in written English.
It is commonly used in the context of conflict or opposition, meaning to fight against or struggle with. Example: The army was combatted by the enemy's relentless attacks, but they managed to hold their ground.
"There are symptoms of intolerance and anti-semitism in Poland which must be combatted by the government.
Dismal living conditions and extensive displacement must be combatted by adopting measures that temper the effect of market forces.
Sexism — the conviction that women don't deserve equal pay, political rights, or access to education — can be combatted by argument, by anti-discrimination laws, and by giving women the opportunity to prove their ability.
"The Expendable Man" does not suggest that racism can be combatted by action or waited out in time; it is a disease, and it must be quarantined, the scene fled.
Experience with chemotherapy led to the conviction that the ingenious adaptability of the cancer cell had to be combatted by using varied "cocktails" of cytotoxins, by continuing chemo long after signs of remission, and by delivering doses that might cause excruciating pain to patients and also constitute an independent danger to their lives.
At the receiver, SI is combatted by application of a linear Minimum Mean Square Error (MMSE) receiver, cf. [44].
I also have a terrible sweet tooth, which I combat by simply not buying junk food when I shop for groceries (although I will indulge on rare occasions).
Foam with a relatively large bubble diameter is easy to combat by diet or starvation and by the use of stirrers.
Some innovative examples developed by researchers to combat cancer by the EPR mechanism are also discussed.
The molecular mechanisms used by hemipterans to combat attacks by biological control agents are completely unknown.
The EU should combat radicalisation by addressing exclusion, not by conflating conservative religious faith with terrorism.
