Hippocrates, the great Greek physician of the 4th century BC, already said that all disorders originate in the gut. And anxiety and depression just seem to be no exception. But let's proceed in order and try to understand how a connection between gut and mood is possible and, above all, what we can do to improve the situation.
Anxiety and gut, the connection
Well, the state of health of our gut goes far beyond the ability to determine digestive processes. In fact, experts know what is called the gut-brain axis, a real connection between these two organs that leads, in the case of intestinal inflammation, to an increased risk of developing anxiety and depression, so much so that it is estimated that, among all those suffering from intestinal inflammation, 90% may develop anxiety and depression (Carloni et al, Science, Oct 2021). But how is it possible that colitis, ulcerative colitis and Crohn's disease can manage our moods? A recent Italian study was able to demonstrate the mechanism underlying this association. In particular, intestinal inflammation makes the intestinal barrier more permeable causing the inflammation to spread beyond the intestine. The brain, in turn, is equipped with a protective barrier placed at the height of the choroid plexus, which is a structure inside the cerebral ventricles and which performs the function of a gate, closing and blocking the pro-inflammatory substances coming from the blood, to prevent them from reaching the brain. The problem is that this causes the alteration of some brain functions, increasing anxious behaviors and even reducing short-term memory (Carloni et al, Science, Oct 2021). Therefore, a first step to counteract anxiety and depression is to take care of your gut and of the microbiota, which is the set of intestinal bacteria, to counteract inflammation there. In fact, an unbalanced and poorly diversified microbiota causes an increase in pro-inflammatory substances, while a microbiota in which good bacteria prevail allows for good intestinal balance and the release of anti-inflammatory substances. But how can we do it? Today's article is dedicated to that.
Probiotics help against anxiety and depression
Probiotics are live organisms that, once taken, overcome the stomach barrier and reach the intestine where they bring benefits to the body. Studies have observed that the intake of probiotics, which can be found in pharmacies or are added to drinks or yogurts that carry it on the label, are able to reduce anxiety and depression, even by 50% (Gambaro et al, Brain Behav, 2020). The main probiotics that bring benefits in case of anxiety and depression are Bifidobacterium infantis, Bifidobacterium longum, Lactobacillus rhamnosus, Lactobacillus paracasei and Lactobacillus plantarum (Ross et al, Explore, 2003).
Don't miss prebiotics for mental health
Against anxiety and depression don't forget about prebiotics, which are found in foods such as chicory, dandelion, chia seeds, onion, garlic, artichokes, Jerusalem artichokes, oats, barley and almonds. Prebiotics are a type of fiber capable of nourishing and supporting good intestinal bacteria, which in turn produce anti-inflammatory substances and help improve mental health (Ansari et al, Curr Pharm Biotechnol, 2020).
The Mediterranean diet counteracts anxiety and depression
The Mediterranean diet, thanks to the high presence of fibers, antioxidants and anti-inflammatory substances, has been shown to reduce the risk of developing anxiety and depression (Zamani et al, J Nutr Metab, 2023). Green light every day therefore to fruit, vegetables, whole grains, nuts, oilseeds and extra virgin olive oil, from two to four portions a week we can consume poultry and fish, legumes and eggs while the Mediterranean diet requires to be consumed in small size, less than twice a week, red and processed meats and desserts. Instead, the intake of highly processed foods, such as sausages, but also candies, crisps or sugary drinks, is connected to an increased risk of anxiety and depression. The explanation is that these foods contain substances that can alter the intestinal microbiota, increase inflammation and thus also affect mental health. On the basis of studies, for example, some emulsifiers, such as carboxymethylcellulose and polysorbate-80, or even titanium dioxide, used as a coloring agent, are considered particularly harmful. Some sweeteners, such as aspartame and saccharin, can instead alter the release of neurotransmitters and thus mood (Lane et al, Nutrients, 2022).
Anxiety and depression are counteracted with some teas
Jasmine tea has been shown to reduce anxious behaviors and depression thanks to its action at the level of the microbiota, thus involving the gut-brain axis. Indeed, jasmine tea is able to support the microbiota, diversifying it and increasing the proliferation of good bacteria (Zhang et al, Nutrients, 2022). Green tea has also been shown to act by protecting the microbiota, reducing the presence of bad and pro-inflammatory bacteria and simultaneously increasing bacteria with an anti-inflammatory action (Perez Burillo et al, Molecules, 2021).
