Purpose of Review <p>Substance Use Disorders (SUDs) remain a major global health burden, with millions affected and high relapse rates despite advances in neurobiological and psychosocial research. Traditional treatments often show limited efficacy, highlighting the urgent need for innovative therapeutic approaches. This review focuses on the role of the NLRP3 inflammasome at the intersection of aging, gut dysbiosis, and SUDs, with particular attention to opioids such as morphine.</p> Recent Findings <p>Emerging evidence suggests that immune mechanisms, especially those mediated by NLRP3 activation, contribute to opioid tolerance and addiction-related neuropathology. Concurrently, global aging trends are increasing the proportion of older adults vulnerable to SUDs. Aging is linked to gut microbiota disruption, or dysbiosis, which triggers chronic low-grade inflammation through the NLRP3 pathway. This age-related inflammatory state exacerbates neuroimmune alterations driven by substance use, amplifying the risk of dependence and associated complications in older populations.</p> Summary <p>The convergence of SUDs, gut dysbiosis, and aging underscores the central role of the NLRP3 inflammasome in addiction-related neuroinflammation. Understanding how age-mediated NLRP3 activation disrupts the gut-brain axis may guide the development of novel therapeutic strategies. Targeting this pathway holds promise for mitigating addiction and improving outcomes, particularly in vulnerable aging populations.</p>