Was sind Psychobiotika?

Microorganisms inhabiting the human body, including the digestive system, form a collection known as the gut microbiota. Research on this topic began with the development of molecular biology, and particularly interesting are the relationships between the composition of the microbiota and human health. The gut microbiota has an impact on digestion, the immune system, and mineral metabolism. In addition, there is a connection between the digestive system and the central nervous system, known as the gut-brain axis.

Psychobiotics are a type of probiotics that can exert a positive effect on the functioning of the brain-gut axis when taken in the appropriate quantity. The term was introduced in 2013 by two researchers - psychiatrist T. Dinan and neurologist J.F. Cryan. However, this does not mean that probiotics have not been tried before in the therapy of mental disorders. As early as 1910, a study was conducted which showed that lactic acid bacteria have a positive effect on the self-feeling of people with depression (J.G.P. Phillips 1910). Probiotic microorganisms actively produce neurotransmitters such as serotonin, dopamine, and gamma-aminobutyric acid. Serotonin is responsible for the regulation of mood and proper functioning of the nervous system, dopamine is also responsible for well-being, while gamma-aminobutyric acid is a neurotransmitter that has a positive effect on the reduction of stress and anxiety. Psychobiotics have a special significance for people with mental disorders, as they can have an effect on the functioning of the brain (H. Karakuła-Juchnowicz et al. 2015).

In recent years, it has been observed that the impact of psychological probiotics on brain function encompasses neuronal, hormonal, and immunological mechanisms, leading to investigations into the role of intestinal microorganisms in the development of many neuropsychiatric disorders (M. Douglas-Escobar, E. Elliott, J. Neu 2013).

Research has indicated that psychobiotics not only enhance brain function but also display antidepressant and anxiolytic properties. The development of depression is influenced by both environmental and genetic factors. In recent years, there has been growing awareness regarding the involvement of gut microbiota in the pathogenesis of this condition. In one study, it was found that individuals with depression exhibited a higher number of bacteria such as Bacteroidetes and Alistipes (K.M. Bangsgaard Bendtsen et al., 2012). Further investigations also noted an increased presence of Alistipes and Enterobacteriaceae bacteria in the composition of those with depression (H. Jiang et al., 2015). Moreover, certain strains may exhibit anti-inflammatory effects and lower cortisol levels, which hold particular significance in alleviating symptoms of anxiety and depression.

Psychobiotics play a vital role in alleviating symptoms of neurodegenerative diseases such as Parkinson's disease or Alzheimer's Disease. Alzheimer's is a disorder that significantly affects cognitive and memory functions. A study by Cheng and colleagues (2019) found that 12 weeks of milk containing rich strains of bacteria (e.g. L. acidophilus and L. Casei) could improve cognitive function in patients suffering from Alzheimer's. In the case of Parkinson's disease, psychobiotics may increase glutathione levels, which was confirmed in a study by Tamtaji (2019). Glutathione is a potent antioxidant, and low levels are observed in patients with this disorder.

Several studies have also corroborated the beneficial impact of certain strains on enhancing sleep quality. Consumption of fermented milk containing L.. Helveticus CM4 had a positive influence on augmenting sleep efficiency and the frequency of awakenings (S.. Yamamura et al. 2009). Other studies noted improvements in sleep diaries among males ingesting L.. Brevis SBC8803 (Y.. Nakakita 2016).

Certain investigations particularly emphasize the psychobiotic potential of specific bacterial strains. In a review paper from 2016, the implications of particular strains on central nervous system functioning in both humans and animals were presented (H. Wang et al. 2016). – Bacillus coagulans MTCC 5856 – treatment of symptoms of irritable bowel syndrome (IBS) and depression (M. Majeed et al., 2018). – Bifidobacterium longum 1714 – enhances memory and decreases sensitivity to stress (A. P. Allen et al., 2016). – Clostridium butyricum MIYAIRI 588 – can reinforce the therapy of depressive disorders alongside antidepressants (T. Miyaoka et al., 2018). – Lactobacillus gasseri CP2305 – improves sleep quality and reduces stress hormone levels (K. Nishida et al., 2017). – Bifidobacterium infantis – impacts on decreasing inflammatory marker levels (A. Herman, 2019). Annually, there is more information about the influence of psychobiotics on nervous system functioning. At present, it is recognized that the administration of appropriate bacterial strains in suitable amounts can have a substantial impact on enhancing mental health.