iVS-1 Probiotic Intervention Targeting Biological Aging in Midlife Adults

Inclusion Criteria: * Aged 40-75 years. * BMI: 20-34.9 kg/m². * Able and willing to sign informed consent and participate for the study duration. Exclusion Criteria: * Chronic disease history (liver, kidney, heart). * Current pregnancy and/or lactating. * Colonoscopy and/or its preparation within 4 weeks of screening. * Those who intend to have children during study period. * Current probiotic, prebiotics and/or metabolic-altering supplement use. * Those who are unable to cooperate with investigators and testing. * Known history of cancer and/or ongoing cancer treatments. * Abuse of drugs, alcohol, tobacco, nicotine and other substances. * History of cardiac diseases: atherosclerosis, heart failure, unstable angina, stable angina, etc., and chronic hypoxic disease: emphysema, pulmonary heart disease and others related. * History of chronic and major GI disease (pancreatitis, IBS, and IBD) and intestinal surgeries. * Type 1 or 2 diabetes mellitus. * Poorly controlled chronic diseases (hypertension, hyperlipidemia) that are clinically unstable. * Vulnerable groups, including clinically ill, mentally ill, cognitively impaired, minors, and illiterate etc. * Significant weight loss (\>20%) in prior one month. * Conditions affecting safety or outcome integrity.