problem converting from word to pdf - alt text is gibberish of weird numbers letters and symbols

What version update do you have installed in Acrobat?

I can think of two things:

• Is the document that you created in MS Word a scanned document?
• Did you use the MS Word Accessibility checker to identify embedded Font issues and Unicode type before converting to a PDF?

Also, I am wondering if you used the Adobe PDF Maker add-on to convert to PDF directly from Word instead of importing the .docx file with Adobe Acrobat