Nissan Repair: Transmission, nissan pathfinder, reputable repair shop

Question
I have a 2002 nissan pathfinder se with 220,000 miles on it. Great car,no problems however i notice that my transmission is lagging a bit when it shifts (automatic).  I have never had the transmission fluid changed and was told by a very reputable repair shop that if it has never been changed then it would be best not to change it now.  It would cause all sorts of problems... What should i do at this point?  Don't bother with changing the fluid?  Just add fluid?  Do nothing???
Thank you

Answer
Claudia,

Leave the fluid alone since if you change it the transmission will fail soon after.  

Just keep the fluid full and live with it until it fails.  Otherwise, you are looking at a rebuild.  So, save your pennies to do this or trade the car.