Probiotics.....

 didn't try that one but tried Prozyme. I still use a tiny and I mean tiny bit on occasion but using it as described caused some stomach upset for Bugsy.  Now I just give him some live plain yogurt daily

For the money, I like something that has multiple varieties of probiotic organisms and activity above 1 billion (the vast majority of products weigh in at only 10 to 20 million).  For the money they're asking for the Geneflora, I can go to the feed store and buy a couple large (900 gram) tubes of Probios gel, which has two more varities of probiotics and is stabilized in the much more bioavailable gel form and is guaranteed at 10 m CFU.

Prozyme isn't a probiotic, it's a digestive enzyme replacement therapy.  It's primarily useful when the pancreas has been traumatized in some way, including severe gi upset (gastroenteritis) and pancreatitis.

You'll hear two camps on the subject of digestive supplements.  I'm in the camp of "only when needed" - they are tools I hold in reserve for illness or recovery from surgery/accident.  I do use them when starting a new rescue on the food here, but after a couple weeks they get weaned off.

Other people feel that probiotics and digestive supplements help a dog's system cope with the physical ravages of today's urban lifestyle.  There is certainly something to that.  I supplement with omega-3s and antioxidants for that reason.