Great question with no good answer. I have a habit of lumping yeast cultures in with probiotics because the effect is similar, but technically yeast cultures are prebiotics. So I'm guessing you're wondering about feeding a yeast culture and a lactobacillus or other strain of living organism at the same time.

Perhaps sometimes, most of the time probably not. No one has done the head to head research (that I know of) because it would take a huge pool of data to measure a significant difference and doing true research correctly is expensive. Since the return on one can be questionable, I'm personally not going to feed two at the same time.

I like to start cattle with yeast culture in the ration (because I am very confident it will have a positive effect on health and feed intake) but that's typically only for 14-21 days. The folks that make and sell these cultures have data that shows a benefit for feeding it all the way to market, but I question whether I can duplicate that in real life. That's why I prefer the Micro-Aid to others: even if I don't see a performance difference I know I am going to reduce odor and save more nitrogen for the crop ground.