Psychiatria pre prax 2/2023

Microbioma, psychobiotics, the “second brain” theory and their place in psychiatry

Mental health without doubt represents a great problem worthy of general attention and increased vigilance. The WHO talks about an epidemic of the 21st century. More than 2000 years ago, Hippocrates declared that ˝all disease begins in the gut˝ (1). Indeed, the human intestine can be compared to an anaerobic bioreactor, a reservoir of a huge population of microorganisms (called the microbiome). The bidirectional connection and interactions between the brain, the gut, and the gut microbiome is firmly established and undeniable. The microbiome plays a serious role in the field of human health. Dysbiosis of the intestinal microbiota is believed to be a key factor in the development of myriad physical and psychiatric/neuropsychiatric disorders. Current research and studies continuously demonstrate the important role of the gut microflora in the regulation of anxiety, mood, sleep, cognition and pain. Emerging literature and research results really point out that patients suffering from various neuropsychiatric disorders show significant differences in the composition of their gut microbiome, levels of inflammatory and anti-inflammatory blood markers (the mechanism of intestinal protective barrier disruption due to local inflammation, transfer of microbial products from the intestine, systemic activation of inflammation in psychiatric disorders), cortisol etc. Probiotics have been widely discussed not only among us - doctors/physicians, but also among the general population. The topic is being mentioned in the media more and more often than before. Patients and physicians have brought manifold queries. Probiotics are expound as “a live microorganism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness” (7, 8). Probiotics (psychobiotics) and “targeted tailored” treatment with them have become a great challenge in neuropsychiatry nowadays. The potential of psychobiotics in the prevention and treatment of neuropsychiatric disorders is being seriously discussed and investigated. For psychiatrists and physicians in general it is necessary to deep dive into this issue and correctly understand the current body of evidence. Subsequently we need to be able to provide accurate and valid recommendations to our patients about probiotics (psychobiotics) and possibilities of microbiome interventions.

Keywords: gut microbiome, dysbiosis, psychiatry, neuropsychiatry, probiotics, prebiotics, psychobiotics, second brain, depression, anxiety