Hunger hormones, or gut hormones, work to signal the body's state of hunger and fullness. These hormones could potentially serve as a key new treatment for drug and alcohol addiction.
After gut hormones have received attention from scientists seeking to understand ingestive behavior and obesity, researchers have discovered a relation between these particular hormones and addiction.
"Hormones from the gut act in the brain to modulate dopamine signaling, which controls decisions to seek out rewards," explained Dr. Mitchell Roitman from the University of Illinois-Chicago. This explains how food and water become more or less rewarding based on an individuals state of hunger, fullness, or thirst.
Addiction, for example, from cocaine and alcohol act on those same dopamine circuits in the brain, gut hormones could potentially turn their rewarding effects up or down in the same fashion.
Ghrelin, a hunger hormone released by the stomach, can exert its effects on the reward value of alcohol much like it increases the reward value of food, according to results shared by Dr. Lorenzo Leggio, leader of a joint team from the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and the National Institute on Drug Abuse (NIDA). Other gut hormones like GLP-1 and amylin, which are released during the process of ingestion, signal the brain when they had enough to eat.
The NIAAA/NIDA research team has shown that ghrelin promotes the alcohol-seeking behavior in individuals with alcohol use disorder. More recently, the research team studied rats that are genetically insensitive to ghrelin, an approach that further encourages the role of the ghrelin system in alcohol seeking.
"These results provide a strong rationale for clinical trials of GLP-1 analogs for people seeking addiction treatment," says Dr. Heath Schmidt of the University of Pennsylvania's Perelman Medical School. "Medications affecting GLP-1 and amylin are already FDA approved for Type II diabetes and obesity. These drugs could be re-purposed for treating drug craving and relapse."
Substance abuse disorders are currently one of the most prevalent and expensive chronic health problems. According to government statistics, in the United States, over 21 million adults need treatment for alcohol or illicit drug abuse. Behavioral therapy is the standard treatment approach, however, persistent cravings lead to an increase in relapse rates. Presently, only a few medications are approved to help manage cravings, but these medications do not hold high efficacy for all people.
Data from animal experiments and preliminary trials in humans continues to support the gut hormone system as the needed target for novel treatments.
Source: Society for the Study of Ingestive Behavior