Better than a medicine! Probiotics should never be missing in a healthy and balanced diet because of their beneficial effects on the immune system and brain health. In fact, taking probiotics has been shown to help fight viral infections, to reduce allergies and even neurodegenerations. This is what emerges from a very recent review published in Diseases magazine thanks to the work of a team from the United Kingdom (Balta et al, Diseases, 2021).
What are probiotics
Probiotics are live organisms taken with the diet and able to overcome the stomach barrier to enrich and support the intestinal microbiota. A healthy microbiota has beneficial effects on the whole organism, protecting it from infections, inflammation, cellular degeneration and cardiovascular and brain diseases. The review we are talking about today compares the results of previous studies in order to understand the beneficial effects of probiotics on the health of the body, with a particular interest in viral infections, given the moment we are living, but also in allergies and neurodegenerations.
Probiotics and respiratory tract viruses
Rhinoviruses, coronaviruses and influenza are the most common viral infections affecting the respiratory tract, being capable of affecting the lungs as well. Well, probiotics have been shown to help prevent and relieve respiratory infections. In fact, the health of the microbiota and the health of the lungs are linked by the so called lung-gut axis. Therefore, the intake of probiotics not only brings balance to the intestinal environment but also protects the respiratory tract. The proof of this is scientific. The intake of a mix of probiotics, such as Lactobacillus acidophilus, L. plantarum, L. helveticus, L. brevis, L. paracasei, Bifidobacterium lactis and Streptococcs thermophilus, in hospitalized patients with new coronavirus infection reduced by 8 times the risk of respiratory failure, as well as improving any intestinal symptoms. The explanation provided is that these strains of bacteria have stimulated the production of some substances with an antiviral and antioxidant action, such as the NRF2 protein.
Probiotics and allergies
Allergies are excessive responses of the immune system to substances recognized as threats, called allergens, which can be food, pollen, animals, medicines, just to name a few. Treating allergies in children is important as this intervention can help limit or even prevent further treatment during adult life. Well, probiotics have been shown to work by helping to prevent allergies from the first years of life. In fact, several strains of Lactobacillus type bacteria act by modulating the immune system. D tryptophan, which is an isolated compound in Lactobacillus rhamnosus and L. casei, is able to counteract the development of allergies in the respiratory tract by inhibiting the production of Th2 cells of the immune system, responsible for the recognition of foreign substances and therefore for the allergic response of the body.
Probiotics, mood and Alzheimer's
Probiotics are also able to influence the central nervous system, thus also impacting mood, anxiety and cognitive function. In fact, just as there is the lung gut axis, there is also the gut brain axis. Probiotics can stimulate the production of important neurotransmitters such as dopamine, serotonin and GABA, with benefits in cases of depression, anxiety and stress. Not only that, some alterations in the intestinal microbiota can give rise to inflammation in the brain, which in turn can be, in the long run, the antechamber of neurodegenerative diseases, such as Alzheimer's. Therefore, acting on the microbiota, balancing it, would also have benefits on brain health. This finds confirmation thanks to recent scientific research. In fact, it was observed that the intake of the probiotics Lactobacillus acidophilus and L. rhamnosus in animals allowed to reduce the accumulation of beta amyloid protein plaques in the hippocampus, which is the first brain region affected by neurodegeneration. This result is truly remarkable, especially in the light of a very recent scientific research that appeared a few days ago in the prestigious journal Nature Medicine thanks to the work of an American team from the University of Pittsburgh (Pascoal et al, Nature Medicine, 2021). The researchers observed that brain inflammation is precisely the trigger that stimulate the development of the neurodegenerative disease of Alzheimer.