It is a completely different situation facing a bet with a gutshot on the flop in comparison to the turn. If it is on the flop, think about what cards can come on the turn which you can continue to another barrel on. Will a pair give you a lot of equity, backdoor draws? E.G. flop is 762, you have 108 which is a gutshot to the nuts. You can call a lot of bets on this board as most likely a 10, 8 or 9 will be good.
Another Example: K87 and you have 106, here calling with a gutshot isn't the best, because both pairs which you hit won't give you confidence in having the bst hand and even the straight can be counterfeited with river Q,J,10, let alone the fact he may have J10
You have to consider whether the villain is doing this move with AK or not, whether there is bluffs in his range which you may have seen him do previously.