Do I stop taking prebiotics or probiotics before my SIBO test?

You need to stop taking prebiotics 24 hours before taking the SIBO test, and probiotics 48 hours before.

There are very specific instructions on how to prepare for a SIBO (small intestinal bacterial overgrowth) Test. You should follow your prep diet for 24 hours before you start your SIBO test, and you should fast for 12 of those hours. 

The easiest way to do this is to take your test first thing in the morning, after 12 hours of fasting overnight. So if you take your test at 8am, stop eating at 8pm the night before. So, from 8am on the day before your test, you should be following your prep diet.

The prep diet includes only a few foods, and prebiotics are excluded.

Prebiotics are fine to take up until 24 hours before your SIBO Test, and they're fine to take at any point before your Gut Health Test.