i am making a 2 tier fondant cake, and i was told that i could use straws to add support so that the bottom cake would not sink, would straws work?

Absolutely!

make sure they are not the bendable kind, or cut off that end of the straw.
I like to get the florescent colored ones, so you can see them very clearly to take them out when cutting.

Yes they will work get the thick ones though they are better ... And make sure they dont bend if they do cut them..

Hi Ladycakes,

I just did an anniversary cake two weeks ago and used the straws,It worked great!! Actually the cake is posted on this site under anniversary cakes.I had a box of the refill straws for my kids rubbermaid juice box container.These straws were really strong and durable.They were about 4 inches long and more solid than a straw from the convenience store.They were really easy to spot once we cut into the first layer and we just picked them out.Hope this helps!!