Hah. Well done. Eating raw oysters? Been doing it my whole life. Dove for them in Mexico, ate them on the beach. Lovely stuff.
Probiotics, not so much. Your natural flora is 'domestic' and you can indeed feed them. Introducing other strains can run you seriously ill, like my buddy found out a month ago. Dehydrated, he was in some serious danger. You know the lower tract is not ever going to be void of natural micro, so you just have to nurture it. Shoving other bugs down there, you're relying on someone else's micro technique, and you don't know the bugs you're going to get.
All in all, I'm not a believer that you can deliver bugs down there, because that's what the extremes of the gut are for, to eradicate new bugs.