Patients with encephalopathy+opioid use showed lower abundance of the autochthonous families Clostridiales XIV and Lachnospiraceae compared to others with ↓ in Bacteroidaceae relative abundance. PiCRUST evidenced highest aromatic amino acid and endotoxin production in opioid users, who had higher levels of IL-6. This evidence concerns the gene IL6 and Encephalopathy.