Can a Christian choose to circumcise and not to eat pork?
1. some say circumcision is healthy
2. pork contains many viruses, and today's pigs are fed with antibiotics, God knows what's wrong with pig therefore he forbade Israel to eat pork in OT. But why Christians eat pork?
Pigs are really no more unhealthy than other animals, and in fact pigs are among the cleanest domesticated animals humans raise. So health had nothing to do with God forbidding pork, also, it's not pork that is itself forbidden, pigs are just one animal among an entire group of animals which are forbidden; acceptable animals for consumption required that they have a cloven hoof and chew the cud, i.e. ruminants, which is why horse, rabbit, kangaroo, and llamas are also forbidden. Pigs, while having split hooves don't ruminate, and thus aren't kosher; llamas on the other hand do ruminate, but don't have split hooves, and thus aren't kosher. So the issue is not pigs or pork, it's that pigs don't fit the definition of what is kosher, which is that the animal have split hooves and that it chew the cud, both of these criteria are commanded to make the food fit for consumption according to God's instruction to the Jews.
Similarly, there are restrictions on fish and birds. Anything that swims that doesn't have scales is forbidden, that's why clams, lobster, and squid are forbidden, it's also why catfish aren't kosher (catfish, while being fish, don't have scales). Birds of prey are forbidden, so chickens are kosher, hawks and vultures not kosher.
So it's important to understand, pigs aren't prohibited because they are pigs, or because there is anything unhealthy or wrong with pigs; they are prohibited because they fall under the category of prohibited things. Pigs get special attention when it comes to non-kosher food because pigs are the most commonly raised non-kosher livestock in the world, this was as true three thousand years ago as it is today.
So to answer the question: As a Christian you are free to be circumcised or not be circumcised (it doesn't matter either way), and you are free to eat whatever you want, or not eat whatever you don't want. Want to eat pork? Eat pork. Don't want to eat pork? Don't eat pork.
-CryptoLutheran