Probiotics, like organic/all natural/holistic/gmo free is kind of a scam tbth... There is no proof that it helps but it sure can't hurt. For raw feeding you need to make sure you have a good proportion of organ meat and change it up every so often. There are raw feeder wholesalers and delivery groups you can join.

For losing weight you also do not have to go raw, you can go to a good quality food and just decrease the amount. Doesn't have to be something crazy like Eagle Pack $55 for a 30lb bag, it can be Iams or Kirkland or something not too expensive but still a decent food. Get a good measuring device for the feedings and stick to a strict amount and the dog should drop weight.