You could try
vars = regexp( fileread('YourFile.txt'), ' ', 'split');
syms(vars{:});
However, I do not promise that it will work (I cannot test it this evening.) If it does not work, then you will require at least one run-time command evaluation, which is not a good idea.
Have you considered renaming your .txt file as a .m file, adding "syms" to the beginning of the line, and using run() to execute the file as a script?
