Does the 'Touch of Serenity' ability prevent an enemy from using spell-like abilities?
Touch of Serenity: You must declare that you are using this feat before you make your attack roll (thus a failed attack roll ruins the attempt). On a successful hit, the attack deals no damage and bestows no other effect or condition, but the target cannot cast spells or attack (including attacks of opportunity and attacks as immediate actions) for 1 round unless it succeeds on a Will saving throw with a DC of 10 + 1/2 your character level + your Wisdom modifier. You may attempt a touch of serenity once per day for every four levels you have attained (but see Special), and no more than once per round.
I would say yes, because:
Spell-Like Abilities (Sp) Spell-like abilities are magical and work just like spells (though they are not spells and so have no verbal, somatic, focus, or material components).
Spell-Like Abilities (Sp): Spell-like abilities function just like spells, but are granted through a special racial ability or by a specific class ability (as opposed to spells, which are gained by spellcasting classes as a character gains levels).
SLAs are like spells except for the things explicitly described as being different. If you can't cast spells you probably can't cast SLAs either.