Thyme
Another herb that i'm learning about is Thyme - turns out its extremely antimicrobial/ anti-fungal/ antiviral (thats why its an ingredient in a lot of mouth washes). So another thing to chuck into your soups (thyme into that bone broth everyone!), salads, teas.
Especially relevant if you suffer from mouth ulcers/cold sores & also re: IBD some studies show it's helpful to decrease ulcers in UC.