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

The efficacy of Lactobacillus and Bifidobacterium in patients with schizophrenia: a meta-analysis

The modulation of gut microbiota through probiotics holds promise as a novel avenue for schizophrenia treatment. This study aims to analyze probiotic complementary therapy on individuals with schizophrenia systematically, to investigate probiotic efficacy, potential mechanisms, and implications for clinical practice. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched in Medline, Web of Science, Embase, ClinicalTrials.gov, CNKI, VIP, and WanFang databases using keywords ("probiotics" OR "prebiotics" OR "synbiotics" OR "Lactobacillus" OR "Bifidobacterium") AND ("schizophrenia"), focused on randomized controlled trials published before July 1, 2023. Among the identified studies, 8 randomized controlled trials met the inclusion criteria, encompassing a total of 342 participants in the intervention group and 306 participants in the control group. Our analysis revealed a statistically significant reduction (p = 0.03) in the total Positive and Negative Syndrome Scale (PANSS) scores following probiotic treatment in individuals with schizophrenia. While no statistical significance was observed in individual subscales (P > 0.05), significant improvements were noted in insulin levels, Insulin Resistance Index (IRI), and glucose levels. Additionally, the Quantitative Insulin Sensitivity Check Index (QUICKI) demonstrated a significant increase (all P < 0.05). The probiotic intervention significantly reduced gastrointestinal discomfort among schizophrenia patients (P = 0.003). This study suggests that probiotics could hold therapeutic potential for addressing clinical symptoms, abnormal glucose metabolism, and gastrointestinal discomfort in individuals with schizophrenia. Future research should encompass comparative trials employing robust experimental designs to explore the differential effects of various probiotic strains on schizophrenia treatment to provide evidence-based therapeutic approaches. TRIAL REGISTRATION: This review protocol was pre-registered on PROSPERO (No. CRD42023455273).

Gut microbiome and schizophrenia: insights from two-sample Mendelian randomization

Growing evidence suggests a potential link between the gut microbiome and schizophrenia. However, it is unclear whether the gut microbiome is causally associated with schizophrenia. We performed two-sample bidirectional Mendelian randomization to detect bidirectional causal relationships between gut microbiome and schizophrenia. Summary genome-wide association study (GWAS) datasets of the gut microbiome from the MiBioGen consortium (n = 18,340) and schizophrenia (n = 130,644) were utilized in our study. Then a cohort of sensitive analyses was followed to validate the robustness of MR results. We identified nine taxa that exerted positive causal effects on schizophrenia (OR: 1.08-1.16) and six taxa that conferred negative causal effects on schizophrenia (OR: 0.88-0.94). On the other hand, the reverse MR analysis showed that schizophrenia may increase the abundance of nine taxa (OR: 1.03-1.08) and reduce the abundance of two taxa (OR: 0.94). Our study unveiled mutual causal relationships between gut microbiome and schizophrenia. The findings may provide evidence for the treatment potential of gut microbiomes in schizophrenia.

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

BACKGROUND

ADHD is widely recognized as the most prevalent neurodevelopmental disorder in children. Recently, the potential role of gut microbiota as an etiological factor in ADHD has gained attention. This systematic review aims to investigate the potential impact of probiotic supplements on alleviating ADHD symptoms and influencing behavior.

METHODS

PubMed, Web of Science, Cochrane Library, and SCOPUS were searched from inception to May 2023. Only randomized controlled trials that have suitable data of the effects of probiotics/synbiotics on children with ADHD were enrolled. The risk of bias of the included studies was assessed by Cochrane Collaboration risk of bias tool.

RESULTS

Five related randomized controlled trial were evaluated in the current review. Types of interventions ranged from single/multi strain probiotics to synbiotic. The duration of intervention in all of the studies were 2 to 3 months. The assessed outcomes were very diverse and different tools were used to report the symptoms in children. Among those which used Conners' Parent Rating Scale, a decrease in the total score occurred in the probiotic group, compared to the placebo group. An improvement in both intervention and control groups was seen in one study which used ADHD-Rating Scale.

CONCLUSION

In summary, the combined findings from the reviewed studies suggest that probiotic supplements might potentially serve as a complementary intervention for ADHD. However, given the small number of studies, limited sample sizes, and the diversity of probiotic strains, further research is needed to clarify the effects of probiotics in children with ADHD. The observed tolerability of probiotics is noteworthy as none of the studies report adverse effects.

Neuroinflammation and Schizophrenia: New Therapeutic Strategies through Psychobiotics, Nanotechnology, and Artificial Intelligence (AI)

The prevalence of schizophrenia, affecting approximately 1% of the global population, underscores the urgency for innovative therapeutic strategies. Recent insights into the role of neuroinflammation, the gut-brain axis, and the microbiota in schizophrenia pathogenesis have paved the way for the exploration of psychobiotics as a novel treatment avenue. These interventions, targeting the gut microbiome, offer a promising approach to ameliorating psychiatric symptoms. Furthermore, advancements in artificial intelligence and nanotechnology are set to revolutionize psychobiotic development and application, promising to enhance their production, precision, and effectiveness. This interdisciplinary approach heralds a new era in schizophrenia management, potentially transforming patient outcomes and offering a beacon of hope for those afflicted by this complex disorder.

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

Second-generation antipsychotics are mainly used in both acute and long-term treatment of major psychiatric disorders. Although better tolerated than first-generation antipsychotic drugs, they can frequently induce weight gain and metabolic disorders, of these, olanzapine is one of the drugs more likely to induce these side effects. There is consistent evidence of the role of gut microbiota in modulating the gut-brain axis with complex crosstalk with the host involving satiety signaling pathways, food intake behavior, and weight and metabolic regulation. Second-generation antipsychotics induce important gut microbiota modification thus contributing together with the central and peripheral receptors blockade mechanism to weight gain induction and metabolic impairment. These drugs can alter the composition of gut microbiota and induce dysbiosis, often reducing the concentration of Akkermansia muciniphila, a bacterium that is also decreased in patients with diabetes, obesity, metabolic syndrome, or chronic inflammatory diseases. Probiotic administration can be a safe and well-tolerated approach to modulate microbiota and offer an integrative strategy in psychiatric patients suffering antipsychotic side effects. Multiple strain probiotics and Akkermansia muciniphila alone have been administered both in mice models and in clinical populations demonstrating efficacy on antipsychotic-induced metabolic impairment and showing a contribution in reducing induced weight gain. Akkermansia muciniphila can improve several parameters altered by olanzapine administration, such as weight gain, insulin resistance, hyperglycemia, liver function, systemic inflammation, and gut barrier function. Although we do not have jet trials in the psychiatric population, this probiotic may be a complementary approach to treating olanzapine-induced weight gain and metabolic side effects.

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

Psychotropic medication efficacy and tolerability are critical treatment issues faced by individuals with psychiatric disorders and their healthcare providers. For some people, it can take months to years of a trial-and-error process to identify a medication with the ideal efficacy and tolerability profile. Current strategies (e.g. clinical practice guidelines, treatment algorithms) for addressing this issue can be useful at the population level, but often fall short at the individual level. This is, in part, attributed to interindividual variation in genes that are involved in pharmacokinetic (i.e. absorption, distribution, metabolism, elimination) and pharmacodynamic (e.g. receptors, signaling pathways) processes that in large part, determine whether a medication will be efficacious or tolerable. A precision prescribing strategy know as pharmacogenomics (PGx) assesses these genomic variations, and uses it to inform selection and dosing of certain psychotropic medications. In this review, we describe the path that led to the emergence of PGx in psychiatry, the current evidence base and implementation status of PGx in the psychiatric clinic, and finally, the future growth potential of precision psychiatry via the convergence of the PGx-guided strategy with emerging technologies and approaches (i.e. pharmacoepigenomics, pharmacomicrobiomics, pharmacotranscriptomics, pharmacoproteomics, pharmacometabolomics) to personalize treatment of psychiatric disorders.