Summary: New randomized, double-blind research indicates that a daily supplement combining probiotics with vitamin D may improve cognitive performance in adults living with schizophrenia. In a 12-week trial of 70 participants, those who received the probiotic-plus-vitamin D supplement showed measurable gains on a standard cognitive assessment, while overall symptom severity assessed by clinical scales did not differ significantly between groups.
Key Facts:
- Combined probiotic and vitamin D supplementation was associated with improved cognitive function in people with schizophrenia.
- Mental performance measured by the Montreal Cognitive Assessment (MoCA) increased in the supplement group.
- Clinical symptom severity measured by the Positive and Negative Syndrome Scale (PANSS) did not show a significant difference between groups.
Source: Wiley
Background: Prior studies have suggested links between gut microbiome imbalances, vitamin D deficiency, and psychiatric conditions including schizophrenia. This trial explored whether targeting the gut microbiota and restoring vitamin D levels could produce measurable benefits in cognition and clinical status.
Published in Neuropsychopharmacology Reports, the study tested a combined probiotic and vitamin D supplement in adults diagnosed with schizophrenia. The trial was designed as a randomized, double-blind, placebo-controlled study over 12 weeks, focusing primarily on cognitive outcomes and disease severity.
Seventy adults with schizophrenia were randomized to receive either a placebo (n = 35) or a daily probiotic supplement together with 400 IU of vitamin D (n = 35) for 12 weeks. Investigators assessed cognitive function using the 30-point Montreal Cognitive Assessment (MoCA) and measured psychiatric symptom severity with the Positive and Negative Syndrome Scale (PANSS). Secondary measures included metabolic and inflammatory markers such as total cholesterol (TC), fasting blood sugar (FBS), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), body mass index (BMI), and reports of gastrointestinal (GI) symptoms.
Sixty-nine participants completed the full 12-week protocol. The MoCA score increased by an average of 1.96 points in the group receiving probiotics plus vitamin D compared with placebo (p = 0.004). In addition, the proportion of participants achieving MoCA scores of 26 or higher—an indicator commonly used to suggest normal cognitive function—rose significantly in the intervention group (p = 0.031). These changes indicate a statistically significant improvement in cognitive screening performance over the study period for those taking the supplement.
Although the probiotic-plus-vitamin D group showed a mean reduction in PANSS score of 2.82 units, this change was not statistically different from the placebo group (p = 0.247), meaning the trial did not demonstrate a clear effect on overall clinical symptom severity. Among secondary outcomes, the supplement group experienced significant improvements in several metabolic and inflammatory markers: total cholesterol (TC) decreased (p = 0.011), fasting blood sugar (FBS) decreased (p = 0.009), and C-reactive protein (CRP), a marker of systemic inflammation, decreased substantially (p < 0.001) compared with placebo.
“Probiotics may be a novel way to treat mental disorders by regulating gut microbiota,” said corresponding author Gita Sadighi, MD, of the University of Social Welfare and Rehabilitation Sciences in Iran, highlighting the study’s focus on the gut–brain axis and potential adjunctive strategies for cognitive symptoms in schizophrenia.
About this schizophrenia research news
Author: Sara Henning-Stout
Source: Wiley
Contact: Sara Henning-Stout – Wiley
Image: The image is credited to Neuroscience News
Original Research: Open access.
Title: Co-administration of probiotic and vitamin D significantly improves cognitive function in schizophrenic patients: A double-blinded Randomized controlled trial by Gita Sadighi et al., published in Neuropsychopharmacology Reports.
Abstract
Co-administration of probiotic and vitamin D significantly improves cognitive function in schizophrenic patients: A double-blinded Randomized controlled trial
Aim
This trial evaluated whether manipulating the intestinal microbiome with probiotics together with vitamin D supplementation could improve cognitive function and reduce disease severity in adults with schizophrenia. The investigators hypothesized that addressing gut dysbiosis and vitamin D insufficiency would produce measurable benefits, particularly in cognition.
Methods
Seventy patients aged 18 to 65 years diagnosed with schizophrenia were enrolled and randomized into two groups: placebo (n = 35) and intervention (probiotic supplements plus 400 IU vitamin D daily, n = 35). Primary outcomes were cognitive function assessed by the Montreal Cognitive Assessment (MoCA) and psychiatric symptom severity assessed by the Positive and Negative Syndrome Scale (PANSS). Secondary outcomes included lipid profile, fasting blood sugar (FBS), body mass index (BMI), gastrointestinal symptoms, and inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).
Results
Sixty-nine participants completed the study. The intervention group experienced a statistically significant improvement in MoCA scores, with a mean increase of 1.96 points compared to placebo (p = 0.004). The proportion of participants achieving a MoCA score ≥ 26 also increased significantly in the supplement group (p = 0.031). Secondary metabolic and inflammatory measures improved in the intervention group: total cholesterol (TC) decreased (p = 0.011), fasting blood sugar (FBS) decreased (p = 0.009), and C-reactive protein (CRP) showed a marked reduction (p < 0.001). The reduction in PANSS score in the supplement group (−2.82 units) did not reach statistical significance when compared to placebo (p = 0.247).
Conclusion
The study concludes that co-administration of probiotics and vitamin D over 12 weeks produced measurable improvements in cognitive screening performance among adults with schizophrenia, along with favorable changes in several metabolic and inflammatory markers. While overall psychiatric symptom severity did not change significantly compared to placebo, the cognitive benefits support further investigation of gut-targeted, adjunctive strategies for cognitive impairment in schizophrenia.