Probiotic Impact on Cognitive Performance, and Metabolic Outcomes in Overweight Young Adults With Impaired Glucose Regulation
ID: NCT07073781
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This 12-week, double-blind, placebo-controlled trial will examine whether daily supplementation with the Lab4P probiotic can improve cognitive performance and metabolic health in overweight adults aged 18 to 40 with impaired glucose tolerance, a preclinical condition where blood glucose regulation is mildly disrupted. Seventy participants will be randomly assigned to receive either Lab4P or a placebo. The study will assess changes in memory, executive function, and processing speed, along with blood glucose control, cardiovascular function, cholesterol levels, body composition, and markers of inflammation. The study will also analyse changes in the gut microbiome and evaluate the safety and tolerability of the probiotic.
Read Full Scientific Objectives & Methods
Global rates of Overweight and obesity are rising at unprecedented levels, contributing to increased metabolic disturbances such as impaired glucose metabolism. Disruptions in glucose regulation are both characteristic of and contributory to the pathogenesis of metabolic disorders, including type 2 diabetes (T2D). Clinical perturbations in glucose homeostasis are strongly associated with cognitive impairments, and an increased risk of neurodegenerative diseases. Increasing evidence suggests that even slightly impaired glucose metabolism (IGM) may contribute to cognitive decline. Emerging evidence shows that cognitive impairments, including memory, executive function, and visuomotor deficits, can be observed in young adults with impaired glucose metabolism, alongside early markers of structural and functional brain changes. Neuroimaging studies have revealed reduced white matter integrity and decreased cerebral glucose metabolism in prediabetic individuals aged 22-35, particularly in brain regions associated with attention, self-regulation, and working memory. These neurocognitive effects appear to be driven by early neurovascular unit (NVU) dysfunction, involving elevated blood glucose, insulin resistance (IR), endothelial damage, and inflammation. Exaggerated glucose excursions promote oxidative stress and impair endothelial function at the blood brain barrier, disrupting cerebral blood flow (CBF), glucose transport and metabolic homeostasis. Functional uncoupling between CBF and regional cerebral glucose metabolism has been directly observed in young adults with IR. Together, these findings suggest that NVU dysfunction may underlie early cognitive decline in young adults with IGM, and that this population represents a critical target for early, non-pharmacological intervention. Probiotic formulations, including the probiotic consortium Lab4P, have shown promise in improving metabolic markers and reducing inflammation, with preclinical data suggesting potential cognitive and neuroprotective benefits. However, its procognitive effects in humans remain unexplored. This trial will evaluate whether Lab4P supplementation can enhance cognitive performance, and cardiometabolic regulation in overweight young adults with IGM. By targeting a modifiable risk state early in life, the study aims to determine whether probiotic supplementation can serve as a viable strategy to mitigate long term neurocognitive and metabolic decline.
The investigational product in this study is Lab4P, a patented multi-strain probiotic consortium formulated as a food supplement and supplied in capsule form. Each daily dose contains a total of 5 × 10¹⁰ CFU of live bacteria, comprising five strains: Lactobacillus acidophilus CUL60 and CUL21, Lactobacillus plantarum CUL66, Bifidobacterium bifidum CUL20, and Bifidobacterium animalis subsp. lactis CUL34. In addition to probiotics, each capsule also contains three micronutrients at 100-200% of the recommended daily intake: Vitamin D (10 µg; 200%), Vitamin C (80 mg; 100%), and Zinc (10 mg; 100%). Lab4P is a marketed, human-approved product manufactured by Cultech Ltd. (Port Talbot, UK) and is classified as a food supplement, available for purchase without prescription. Both the active product and placebo will be identically packaged to maintain blinding.
Placebo capsules are composed of microcrystalline cellulose, and are identical in appearance to the test product.
Treatment Arms Description
Experimental group will consume oral dose of 50 billion Colony forming Units (CFU) once daily till delivery.
Microcrystalline cellulose/d each, up till delivery
- Aged 18-40 years
- Body Mass Index (BMI) between 25.0 and 29.9 kg/m² (classified as overweight)
- In good general health (self-reported)
- Normal self-reported sleep patterns, with no history of diagnosed sleep disorders
- Willing and able to provide informed consent
- Able to comply with study procedures, including fasting and oral glucose tolerance testing
- Diagnosed diabetes (any type).
- Diagnosed sleep disorders.
- Fasting glucose \>6.9 mmol/L during screening.
- History of bariatric surgery (e.g., gastric bypass, sleeve gastrectomy).
- Major surgery, significant illness, trauma, infection, or myocardial infarction within the past 6 weeks.
- Current use of medications affecting glucose metabolism or probiotics
- Pregnancy or actively trying to conceive
- Night shift work within the past month
Primary Outcome Measures
- Verbal Memory Performance — Time Frame: Baseline to Week 12 (end of treatment).
Assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB) Verbal Recognition Memory task (VRM) a computerized word list recall task, which measures accuracy in recalling previously presented verbal stimuli to evaluate verbal memory function.
View Secondary Outcome Measures (37)
- Visual Episodic Memory — Time Frame: Baseline to Week 12 (end of treatment).
Measured using the Paired Associates Learning (PAL) task (CANTAB), which assesses the ability to remember the locations of visual patterns and form new associations.
- Number of Participants Reporting One or More Adverse Events (AEs) or Serious Adverse Events (SAEs) — Time Frame: Baseline to Week 12 (end of treatment).
All adverse events (AEs) and serious adverse events (SAEs) will be monitored through participant self-reports and case report forms. Events will be categorized by severity and relatedness to the study product.
- Visuospatial Working Memory — Time Frame: Baseline to Week 12 (end of treatment).
Measured using the Spatial Working Memory (SWM) task (CANTAB), which assesses the ability to temporarily retain and manipulate spatial information and use effective search strategies during problem-solving.
- Executive function (Response Inhibition and Impulse Control) — Time Frame: Baseline to Week 12 (end of treatment).
Measured using the Stop Signal Task (SST) (CANTAB), which assesses the ability to inhibit a dominant or preplanned motor response when signaled.
- Executive function (Cognitive Flexibility and Attentional Set-Shifting) — Time Frame: Baseline to Week 12 (end of treatment).
Measured using the Intra-Extra Dimensional Set Shift (IED) task (CANTAB), which assesses the ability to shift attention between different stimulus dimensions and adapt to changing rules. This evaluates cognitive flexibility and executive function.
- Processing speed, Psychomotor Response, and Attention — Time Frame: Baseline to Week 12 (end of treatment).
Measured using the Five Choice Reaction Time (RTI) task (CANTAB), which assesses how quickly and accurately participants respond to visual stimuli.
- Cerebrovascular Reactivity (CVR) — Time Frame: Baseline to Week 12 (end of treatment).
CVR reflects the ability of cerebral blood vessels to dilate or constrict in response to changes in carbon dioxide, indicating the health of the brain's vascular system. Measured via transcranial Doppler ultrasound of the middle cerebral artery in response to hypercapnia/hypocapnia challenge.
- Flow-Mediated Dilation (FMD) — Time Frame: Baseline to Week 12 (end of treatment).
Measured using ultrasound imaging of the brachial artery before and after a period of blood flow restriction using a pressure cuff. The artery's ability to dilate in response to the return of blood flow (reactive hyperemia) reflects endothelial function, an early indicator of vascular health and cardiovascular risk.
- Global Sleep Quality — Time Frame: Baseline to Week 12 (end of treatment).
Measured using the Pittsburgh Sleep Quality Index (PSQI) global score, a validated 19-item self-report instrument assessing subjective sleep quality over the past month.
- Sleep Latency — Time Frame: Baseline to Week 12 (end of treatment).
Assessed as a PSQI subcomponent, defined as the self-reported time (in minutes) taken to fall asleep on most nights.
This trial is recruiting at 1 study facilities worldwide. Click below to see if there is a clinic or hospital in your area:
Show All 1 Facilities & Contact Sites
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- Zilliox LA, Chadrasekaran K, Kwan JY, Russell JW. Diabetes and Cognitive Impairment. Curr Diab Rep. 2016 Sep;16(9):87. doi: 10.1007/s11892-016-0775-x.PubMed ↗
- Webberley TS, Bevan RJ, Kerry-Smith J, Dally J, Michael DR, Thomas S, Rees M, Morgan JE, Marchesi JR, Good MA, Plummer SF, Wang D, Hughes TR. Assessment of Lab4P Probiotic Effects on Cognition in 3xTg-AD Alzheimer's Disease Model Mice and the SH-SY5Y Neuronal Cell Line. Int J Mol Sci. 2023 Feb 28;24(5):4683. doi: 10.3390/ijms24054683.PubMed ↗
- Sadler JR, Shearrer GE, Burger KS. Alterations in ventral attention network connectivity in individuals with prediabetes. Nutr Neurosci. 2021 Feb;24(2):140-147. doi: 10.1080/1028415X.2019.1609646. Epub 2019 Apr 28.PubMed ↗
- Ribeiro M, Yordanova YN, Noblet V, Herbet G, Ricard D. White matter tracts and executive functions: a review of causal and correlation evidence. Brain. 2024 Feb 1;147(2):352-371. doi: 10.1093/brain/awad308.PubMed ↗
- Repple J, Karliczek G, Meinert S, Forster K, Grotegerd D, Goltermann J, Redlich R, Arolt V, Baune BT, Dannlowski U, Opel N. Variation of HbA1c affects cognition and white matter microstructure in healthy, young adults. Mol Psychiatry. 2021 Apr;26(4):1399-1408. doi: 10.1038/s41380-019-0504-3. Epub 2019 Aug 29.PubMed ↗
View Official Medical/Scientific Title
A Double-blind Placebo-controlled Exploratory Trial to Assess the Impact of Daily Lab4P Probiotic Supplementation on Cognitive Performance and Metabolic Regulation in Overweight Young Adults With Impaired Glucose Regulation