Impact of the Microbiota on the Gut-Brain Axis and its Influence on Anxiety: A Systematic Review

Background: he gut-brain axis is a bidirectional connection that communicates the gastrointestinal system and the central nervous system (CNS), through nervous, immunological, endocrine and metabolic pathways. In this context, the gut microbiota refers to the set of microorganisms that inhabit the gastrointestinal tract and play a key role in the regulation of mental and emotional health, including anxiety. Research has shown that an imbalance in the gut microbiota, known as dysbiosis, can alter the gut-brain axis and contribute to the development of anxiety disorders, through inflammatory and neurochemical mechanisms. Objectives: In this work we will conduct a literature review on the relationship between the gut-brain axis, the gut microbiota and anxiety, including the potential use of probiotics in mental health. Material and methods: The proposed research design is a systematic review, the main objective of which is to determine the differences in young adult patients with anxiety treated with probiotics. Results: Given the role of the gut microbiota in the gut-brain axis due to its ability to produce neurotransmitters (e.g., GABA by Bifidobacterium) and their precursors, as well as cytokines, BDNF, and SCFAs, several efforts have been made to establish a microbiological signature in individuals with anxiety disorders. Conclusion: The use of probiotics influences the inflammatory profile of patients and the regulation of the serotonin pathway. These findings support the therapeutic potential of probiotics in the treatment of anxiety, as these disorders are associated with alterations in the HPA axis and elevated levels of inflammatory biomarkers in patients with anxiety.