I upgraded QgisQGIS from 2.18.0 to 2.18.14 but I losted Saga in processing tools.
First I tried to disable/reactivate it in processing > options > providers but nothing.
I searched some solution on web and I saw that I can't change Saga folder in providers.
So I find a way to change it in QGIS advanced options > processing > configuration menu. I tried some folders but nothing worked...
In others gis stackexchange posts people said to use Osgeo4W Saga installation but i'm on mac OS not on Windows...