Dysbiosis and neuroinflammation: two sides of the same coin

Low grade inflammation is the silent disease of the 21st century. And neuroinflammation is specifically inflammation which occurs in neurons. According to Professor Bruno Ribeiro, head of the Cognitive Development unit at SHA Wellness Clinic, neuroinflammation has three clearly identified culprits: alcohol consumption, chronic stress and the intake of processed foods.

“Alcohol produces intense inflammation in our brains, as has been shown in experiments with laboratory mice injected with ethanol. Depending on what we drink and eat, we send warning messages to the body that are interpreted as potential threats and the body responds by generating hyperinflammation,” the expert explains.

Two large families of cells coexist in the brain, neuronal cells and glial cells. The latter are ten times more abundant than the former and multiply very easily. Their main function is to care for neurons and form the blood-brain barrier that protects them.

“The neuroinflammation caused by binge drinking (defined as consuming five or more units of alcohol in the same occasion for men, and four or more in women) produces significant inflammation in the nervous system. As we explained, glial cells have the capacity to protect neurons, but if alcohol is consumed intensively and very frequently, these cells weaken and fail to block neuronal inflammation, which is when neuronal loss occurs,” explains Professor Ribeiro, who points out that, in a chronic process of alcohol consumption, a type of dementia called Wernicke-Korsakoff’s dementia can develop, which is caused by neuroinflammation.

More than a decade ago, a team of scientists at the Príncipe Felipe Research Centre (PFRC) demonstrated for the first time how the neuroinflammation produced by chronic alcohol consumption causes abnormalities in the myelin, a substance in the nervous system responsible for the transmission of nerve impulses along neurons.

The scientists described how chronic alcohol consumption disintegrated the myelin sheath covering the axons of neurons and how neuroinflammation caused caused by ethanol was involved in these myelin abnormalities. That study sought to elucidate whether chronic alcohol consumption was related to abnormalities in the so-called “myelin sheath”. The finding was that alcohol disintegrated the myelin sheath, left neurons unprotected, and contributed to neurodegeneration.

On the other hand, it has been investigated that excessive alcohol consumption also affects the gut bacteria equilibrium and promotes gut dysbiosis. This is the common link shared by dysbiosis and neuroinflammation.

A gut dysbiosis occurs when the equilibrium between the bacteria in the microbiota is disturbed due to changes in their composition, distribution or functioning.

Researchers at the University of California have shown that alcohol consumption leads to a reprogramming of the gut microbiota caused by acetate produced by the liver which spreads through the intestines and represents a source of carbon which encourages bacterial growth.

Dr. Marien Silva from SHA Wellness Clinic’s Well-ageing Medicine Department knows how to recognise dysbiosis from the symptoms reported by the patient. “Normally the patient says that whatever he or she eats, he or she is always inflamed, a feeling in women similar to pregnancy, of being always swollen. This sensation is sometimes accompanied by diarrhoea and intestinal discomfort.

Usually, a dysbiosis test is ordered to see the state of the microbiota. The test reveals how many “good” bacteria there are, how many “bad” bacteria there are, which ones are missing, the state of the intestinal mucus , and the permeability of the mucosa; it will also tell if the enzymes are changed. With this information, a specific treatment plan is created,” explains Dr. Silva, who points out that, in order to determine the diagnosis, intolerances and diseases such as coeliac disease must be ruled out.

She says that any treatment for dysbiosis always rests on three pillars: diet, exercise and stress management, because there is a bidirectional relationship between the brain and the gut, which explains neuroinflammation. “You have to break that cycle by working with probiotics and prebiotics and with specific supplementation for the inflammation, but stress management is also important, with practices such as yoga, pranayama, mindfulness, contact with nature, and good time management. It’s important to make time for being with yourself and with your friends,” says Silva.

The experts consulted clarify that neuroinflammation is an ancestral defence mechanism of the brain, the problem is when it starts to become chronic due to exposure to continuous stressful situations or the consumption of alcohol or processed foods. “One of the mechanisms to reduce neuroinflammation is to reduce daily food intake. Intermittent fasting, magnesium and curcumin help both neuroinflammation and intestinal inflammation,” says Dr Silva. While stress, diet, alcohol and toxins cause neuroinflammation.

With improved diet and stress management, dysbiosis improves and, consequently, the disruption of intestinal permeability. As a result, all symptoms of neuroinflammation will be reduced.