Study of Yili Mei Yi Tian Active Lactobacillus Drink to Improve Immunity and Digestive System

Inclusion Criteria: * Age 25 to 45 years sub-health white-collars, catch cold for 4 to 6 times in last year, with low immunity; * Non-specific and/or moderate constipation; * Irregular or occasional gastrointestinal disorders (flatulence, gurgling, feeling heavy after eating, abdominal pain); * Slow transit or irregular bowels movements (abnormal feces solidity, bowel movements decreased, e.g. every 2-3 days or less than 3 times per week); * Able to understand the nature and purpose of the study including potential risks and side effects; * Willing to consent to study participation and to comply with study requirements Exclusion Criteria: * Diagnosed as immunity-low associated with chronic disease; * Diagnosed as chronic constipation; * Treated gastrointestinal symptoms; * Currently suffering from diarrhea; * Suffering from rhinitis chronic, laryngitis, labored breathing that similar to flu symptoms. Such as chronic allergic rhinitis, asthma, COPD; * Treatment by analgesic such as aspirin and paracetamol; * Had laxatives or other remedies to promote digestion 2 weeks prior to the study start; * Consuming dairy products or supplements containing pro/pre-biotic 10 days prior to the study start; * Long-term use of any prescription or OTC medication that inhibit or prevent flu symptoms, including but not limited to, antihistamine, pectoral, high doses of vitamin C; * Recent use (within 3 months of screening) of any prescription or OTC medication that significantly affects immune response, such as antibiotic; * Recent inoculation (within 6 months of screening) of influenza vaccine, or other vaccine in 15 days; * History of alcohol, drug, or medication abuse; * Pregnant or breastfeeding women; * Participation in another study with any investigational product within 3 months of screening * Any comorbidity that could, in the opinion of the investigator, preclude the subject's ability to successfully and safely complete the study or that may confound study outcomes