Probiotics, Cognition and Metabolic Health in Young Adults With Overweight or Obesity

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 and obese adults aged 18 to 40. 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.

INCLUSION CRITERIA Written informed consent provided before any study-related procedures. Aged 18-40 years, inclusive, at the time of consent. BMI ≥25.0 kg/m². Self-reported good general health, with no chronic medical conditions requiring ongoing treatment. Self-reported normal sleep patterns, with no history of diagnosed sleep disorders. Willing and able to comply with study procedures, including fasting and oral glucose tolerance testing (OGTT). Non-smoker at screening, with no regular tobacco use in the preceding six months. English proficiency equivalent to that of a native speaker. EXCLUSION CRITERIA Current or past diagnosis of diabetes mellitus of any type. Fasting plasma glucose ≤3.9 or ≥7.0 mmol/L at screening. Diagnosed sleep disorder. History of bariatric surgery or other gastrointestinal procedures that may affect glucose absorption or metabolism. Major surgery, significant trauma, systemic infection, or myocardial infarction within six weeks before screening. History of kidney disease, liver disease, low or high blood pressure, or heart disease. History of conditions that may affect food metabolism, including food allergies or gastrointestinal diseases such as irritable bowel syndrome or peptic ulcers. Current or recent use, within four weeks, of medications affecting glucose metabolism or agents that may alter gut microbiota composition or probiotic efficacy, as defined in Section 8.6. History of psychiatric illness, including anxiety or depression. Current use of prescription or over-the-counter medications, excluding hormonal contraception. Night shift work within 30 days before screening or planned during the study. Pregnancy, breastfeeding, or plans to become pregnant during the study. Known allergy or hypersensitivity to any component of the investigational product or placebo.