Related paper on the immune system triggering anxiety: "Stress-Induced Metabolic Disorder in Peripheral CD4+ T Cells Leads to Anxiety-like Behavior" https://doi.org/10.1016/j.cell.2019.10.001

Related: "N-acetylcysteine as a new prominent approach for treating psychiatric disorders" https://doi.org/10.1111/bph.15456 section "2.3 Regulation of inflammatory mediators".

N-acetylcysteine (NAC) is considered safe and is sold as a diet supplement in USA and many other countries. If you suffer from anxious feelings, 1200mg/day NAC may reduce them a lot.