Abbreviations 1MT: 1-methyl-tryptophan 3HAA: 3-hydroxyanthranilic acid 3HK: 3-hydroxykynurenine 5-HT: Serotonin 7nAChRs 7: nicotinic acetylcholine receptors AHR: Aryl hydrocarbon receptor AMPAR: -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor BBB: Blood brain barrier BCG: Bacile Calmette-Gurin BDI-II: Beck Depression Inventory, 2nd edition BDNF: Brain-derived neurotrophic factor BSSI: Beck Scale for Suicidal Ideation CDRS-R: Childrens Depression Rating Scale-Revised CNS: Central nervous system ESBA: (S)-4-(ethylsulfonyl)benzoylalanine GBA: Gut-brain axis HAMD: Hamilton Depression Rating Scale HPA: Hypothalamic-pituitary-adrenal IDO: Indoleamine 2,3-dioxygenase KAT: Kynurenine aminotransferase KMO: Kynurenine 3-monooxygenase KP: Kynurenine pathway K-SADS-PL: Schedule for Affective Disorders and Schizophrenia for School-Age Children KYN: Kynurenine KYNA: Kynurenic acid LDH: Lactate dehydrogenase LPS: Lipopolysaccharide LSD: Lysergic acid diethylamide MDD: Major depressive disorder NMDAR: N-methyl-D-aspartate receptor NO: Nitric oxide PA: Picolinic acid QA: Quinolinic acid ROS: Reactive oxygen species SCFA: Short-chain fatty acids SSRI: Selective serotonin reuptake inhibitor TBI: Traumatic brain injury TDO : Tryptophan 2,3-dioxygenase TRP: Tryptophan UCMS: Unpredictable Chronic Mild Stress References Cipriani A, Furukawa TA, Salanti G, Chaimani A, Atkinson LZ, Ogawa Y, et al

Downstream analysis was conducted with the compassR package and differential metabolic states were determined with a Wilcoxon Rank Sum Test on the Compass reactions
Acetic acid water has no preservative, so it cannot be used safely for multi-draw vials
To differentiate between hyperthyroidism and drug-related liver injury, it is recommended to check baseline liver enzymes prior to initiation of treatment
A mucolytic is a substance that helps break down and thin out mucus, making it easier to clear from the respiratory tract