Wasabi is the ground root stalk of Wasabia japonica. You know its sharp, nasal heat from sushi, but concentrated extracts appear in capsules too.
The root provides isothiocyanate compounds. Lab work shows these molecules can act against microbes and dial down inflammatory pathways. A smaller number of people take wasabi capsules to help maintain a clean mouth and comfortable digestion. Clear human evidence is scarce.
Take the capsules with food. Few supplement users reach for powdered or paste forms on their own because the flavor is so strong. If you are allergic to mustard, cabbage, or other brassica family plants, skip wasabi. Interaction data is thin, so talk to a doctor if you take regular medication.