Reviewing the Potential Therapeutic Approaches Targeting the Modulation of Gastrointestinal Microflora in Schizophrenia

Abstract

Schizophrenia (SCZ) is a severe brain disorder characterized by an intriguing clinical panel that has begun to gain interest due to its particular phenotype. Having considered the role of gut microflora in psychiatry, the latest discoveries might offer further insight into the underlying mechanisms. Thus, we aimed to offer an updated overview of the therapeutic potential of microorganism-derived supplements alongside dedicated protocols that target the re-establishment of the host’s eubiosis. Based on combinations of specific keywords, we performed searches in four databases (PubMed/Medline, ISI Web of Knowledge, Scopus, and ScienceDirect) for the established interval (2018–2022) and identified twenty two eligible cases, restricted only to human patients’ experiences. Up until the writing of this manuscript, it has been revealed that the administration of specific lactic acid bacteria strains (Lactobacillus and Bifidobacterium), or those combined with vitamin D and selenium, maintain the integrity of the gut flora, preventing antagonistic effects including inflammation, antipsychotic-related body weight gain (olanzapine) and other metabolic dysfunctionalities. However, there are multiple antipsychotics that exert a potent effect upon gut flora, influencing a plethora of pathways and creating a dysbalance ratio between beneficial and opportunistic pathogens. Risperidone, amisulpride, and clozapine are just a few examples, but the current literature is unfortunately inconsistent and reported data is contradictory, which is why we support additional studies in this context. Moreover, we further argue the utility of studying how distinct controlled substances influence microbial communities, considering that ketamine is proved to alleviate depressive-like behavior as opposed to amphetamine and phencyclidine, which are known substances to trigger SCZ-like symptoms in experimental models. Probiotics may be regarded as the most consequential vehicle through which the gut flora can be successfully influenced, in adequate doses exerting a beneficial role as an alternative approach to alleviate SCZ symptoms.

A Possible Role of Akkermansia muciniphila in the Treatment of Olanzapine-Induced Weight Gain

“…Gut microbiota is involved in the regulation of every physiological host process and participates in xenobiotic and drug metabolism, often participating in their therapeutic effect; however, at times drug microbiota modification can contribute to some side effect manifestations [42]. Psychotropic drugs can influence gut microbiota compositions, and in some cases, they can exert antimicrobial properties [14,43].…”

The emergence, implementation, and future growth of pharmacogenomics in psychiatry: a narrative review

“…Moreover, modification of medications by specific bacteria may result in an increase in active metabolites, which could increase response or perpetuate adverse drug reactions (Wan & Zuo, 2022; Zeng et al, 2021). Therefore, the presence of specific drug-interacting microbial species may serve as a biomarker of efficacy or tolerability to specific medications or guide modification of the microbiota to enrich beneficial species to optimize response to medications (Nita et al, 2022). Notably, the current evidence in psychiatry is primarily based on preclinical studies (Cussotto et al, 2019).…”

Probiotics as a Promising Therapy in Improvement of Symptoms in Children With ADHD: A Systematic Review

“…There is evidence suggesting that the vagus nerve, hormones, immune activity mediators, as well as the gastrointestinal microbiota and their metabolites might play a role in the bidirectional communication between gut microbiota and CNS. A number of studies in recent years suggest that imbalances in GI microflora can impact brain physiology, cognition, and behavior (Arneth, 2018; Nita et al, 2022).…”