What to do when your bot is just out of it?

So as a jungler or mid I will gank bot when it behooves me. I get kill for ADC or me or at least burn sums and deny cs. Even with all that when the lane just feeds with an advantage past lvl 3-6. What can I do besides focus top and mid towers to offset the crappy bot my team received? I give teammates benefit of the doubt until they feed 3 kills resulting in a laner at least a level or two above my laner then i do not even attempt to gank that lane unless another team mate collapses with me or the 2 lvl above me enemy is like 100 health and their jung is on minimap.