The main goal of our research was to study the possible alterations of the chemical coding of the dorsal motor vagal nucleus (DMX) neurons projecting to the porcine stomach prepyloric region following prolonged acetylsalicylic acid supplementation. Fast Blue (FB) was injected into the studied area of the stomach. Since the seventh day following the FB injection, acetylsalicylic acid (ASA) was given orally to the experimental gilts. All animals were euthanized on the 28th day after FB injection. Medulla oblongata sections were then processed for double-labeling immunofluorescence for choline acetyltransferase (ChAT), pituitary adenylate cyclase-activating peptide (PACAP), vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), galanin (GAL), substance P (SP), leu enkephalin (LENK), and cocaine- and amphetamine-regulated transcript (CART). In the control DMX, only PACAP was observed in 30.08 ± 1.97 % of the FB-positive neurons, while VIP, NOS, GAL, SP, LENK, and CART were found exclusively in neuronal processes running between FB-labeled perikarya. In the ASA DMX, PACAP was revealed in 49.53 ± 5.73 % of traced vagal perikarya. Moreover, we found de novo expression of VIP in 40.32 ± 7.84 %, NOS in 25.02 ± 6.08 %, and GAL in 3.37 ± 0.85 % of the FB-labeled neurons. Our results suggest that neuronal PACAP, VIP, NOS, and GAL are mediators of neural response to aspirin-induced stomach inflammatory state.