The Link Between Intestinal Microbiota And Addiction
Due to the large number of contributing factors, addiction is often a very difficult type of condition to treat. Therefore, research is underway in the area on the various mechanisms and concerning possible treatment options. Today we know much more about the link between intestinal microbiota and addiction and the various factors that can trigger it, as well as the role of the intestinal microbiota in detoxification and abstinence.
Microbiota are microbes that live in the mouth, vagina, skin and intestines. Researchers have already linked this ecosystem to a number of other pathologies, such as autism, Parkinson’s disease, anxiety and schizophrenia. In fact, it also seems to play a role in the development of addiction.
Intestinal-brain axis
Today we know that the digestive tract has its own nervous system, the enteric nervous system, which consists of more than 500 million nerve cells. It communicates with the central nervous system (CNS) and contributes to brain balance and brain function.
The communication between these two systems is dynamic and bidirectional. This means that intestinal microbiota can modify the neural activity of the brain and vice versa. But because the brain is protected by the blood-brain barrier, this influence is not direct. The intestinal neurotransmitters act through the cells in the intestinal wall and allow them to communicate with the CNS.
Experts have found that the enteric nervous system has the ability to produce a large part of the neurotransmitters in our bodies, such as dopamine, GABA and serotonin.
Intestinal microbiota and addiction
Substance abuse occurs because the specific substances activate the reward center of the brain and stimulate the secretion of neurotransmitters, especially dopamine. This gives a very pleasant feeling that the brain quickly gets used to. As a result, it requires higher and higher doses, more and more often.
As we mentioned earlier, we now know that the enteric nervous system also produces neurotransmitters such as dopamine, and that an imbalance in the intestinal microbiota can lead to the development of various pathologies. It can then make this ecosystem susceptible to abuse, with quite dramatic results.
Intestinal microbiota and alcoholism
In 2014, researchers published a study that analyzed the link between intestinal bacteria and alcohol dependence. To do this, the researchers tried to determine if there had been a change in intestinal permeability and intestinal microbiota in people suffering from alcoholism and if it was related to their alcohol dependence.
They found that those who had developed leaky gut syndrome (which is an increased intestinal permeability) had higher anxiety levels and more severe withdrawal symptoms.
In addition, the researchers noticed changes in both the composition of the microbiota and their activity levels. They concluded that intestinal microbiota plays a key role in alcohol dependence, especially in the risk of relapse.
Food addiction
Researchers have also looked at the relationship between food addiction and microbiota by analyzing feces from healthy people, along with their BMI and brain images. To do this, they focused on metabolites, which are produced during the breakdown of tryptophan, an amino acid found in many foods. After breakdown, it is converted to serotonin. Thus, it has a great influence on mood and behavior.
This process has two consequences. One is that when tryptophan has been broken down by the intestinal bacteria, it leaves the body with the feces. The second consequence is that tryptophan is converted to indole during the degradation process, a metabolite involved in the intestinal-brain axis.
The researchers found that indole was related to a higher degree of obesity and an uncontrolled food intake. This is possibly due to its influence on the reward center of the brain, especially on circuits related to the amygdala.
Intestinal microbiota and addiction: treatment options
These results provide a different perspective on addiction, as well as new possible treatment options. Experts hope that restoring the balance of the gut flora can help alleviate some important aspects of addiction.
For example , some researchers suggest altering gut hormones. Others, on the other hand, suggest very simple but effective treatments that are often used in traditional Chinese medicine.
An alternative is fecal microbial transplantation. This procedure basically consists of performing a fecal transplant, during which doctors transfer microorganisms from a healthy donor to the intestine of a recipient.
To date , this treatment has only been shown to be effective in the treatment of chronic colitis. Its use in the treatment of other pathologies is, at least for the time being, purely theoretical. However, researchers continue to investigate the role of the intestinal microbiota in addiction and other diseases in the hope of finding new future treatment options.
