When the microbiome helps the brain‐current evidence

Abstract

The gut microbiota‐brain axis has been recognized as a network of connections that provides communication between the gut microflora and both central and autonomic nervous system. The gut microbiota alteration has been targeted for therapy in various neurodegenerative and psychiatric disbalances. Psychobiotics are probiotics that contribute beneficially to the brain function and the host mental health as a result of an interaction with the commensal gut bacteria, although their mechanism of action has not been completely revealed. In this state‐of‐art review, the findings about the potential therapeutic effects of the psychobiotics alone or in combination with conventional medicine in the treatment of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, as well as in some psychiatric diseases like depression, schizophrenia, and bipolar disorder, have been summarized. The evidence of the psychobiotics therapeutic outcomes obtained in preclinical and clinical trials have been given respectively for the observed neurodegenerative and psychiatric disorders.

The causality between gut microbiome and anorexia nervosa: a Mendelian randomization analysis

“…These microorganisms can modulate individual behavior through various mechanisms, including metabolite, endocrine pathways ( Albillos et al, 2020 ). The gut microbiota’s involvement in the development of neurological disorders through the microbiota-gut-brain axis has been reported for some time ( Schorr and Miller, 2017 ; Mossad et al, 2021 ; Drljaca et al, 2023 ). However, the specific role played by individual microbial groups in this process remains unclear.…”

The influence of the gut-brain axis on anxiety and depression: A review of the literature on the use of probiotics

“…In addition, a study conducted in 1932 confirmed the impact of L. acidophilus on individuals suffering from constipation and mental illness. 91 During the period spanning from the 1950s to the 1980s, the field of probiotic research mainly concentrated on examining various strains that might be obtained from natural sources or derived from human hosts, with a particular emphasis on identifying their methods of action. Further investigation has contributed to the development of knowledge regarding the intricate dynamics between the indigenous microbial communities and their capacity to withstand the infiltration of harmful bacteria, commonly known as colonisation resistance.…”

Fecal and Urinary Adipokines as Disease Biomarkers

“…The latter study showed that fecal lipocalin-2 levels were associated with microbial beta diversity, which describes differential microbiome composition between two communities. Thus, fecal lipocalin-2 levels may emerge as a marker of microbiome dissimilarities ( Figure 2 ) [ 142 ], which are associated with neurological, tumor and liver diseases [ 32 , 144 , 145 ].…”

“…In regard to the utilization of feces for biomarker detection, it has emerged that the gut microbiome can greatly affect the composition of feces, potentially allowing bacterial metabolites to serve as biomarkers for different pathologies. In consideration that disturbed liver and bowel function, and various other disorders such as neurodegenerative diseases, are linked to changes in the microbiome and vice versa, analysis of fecal samples may be attractive for the identification of biomarkers for different diseases [ 32 , 33 , 34 , 35 , 36 ].…”