Comparing the Digestion of Milk With Different Beta-casein Protein Content by Dairy Intolerant Persons

Inclusion Criteria: 1. Ability/desire to provide informed consent 2. Aged 18 to 65 years of age inclusive at screening 3. Current or recent history of intolerance to and avoidance of milk of at least one month duration (by self-report and self-reported symptoms). 4. Agrees to refrain from all other treatments and products used for lactose intolerance (e.g., Lactaid® Dietary Supplements) during study involvement 5. Willing to return for all study visits and complete all study related procedures, including fasting before and during the hydrogen breath tests 6. Qualifying Lactose Challenge Symptom Score: (4 symptom categories with severity measured on from 0 to 5) as defined by one of the following: 1. At least one score of "moderately severe" or "severe" on a single symptom during the 6 hour HBT test; 2. A score of "moderate" or greater for a single symptom on at least two (2) time points during the 6 hour HBT test; 3. At least one "moderate" score or greater on each of two symptoms during the 6 hour HBT test 7. Hydrogen concentration of at least 20 parts per million greater than baseline at least 2 time points during the screening hydrogren breath test 8. Able to understand and provide written informed consent in English Exclusion Criteria: 1. Allergic to milk 2. Currently pregnant 3. Currently lactating 4. Cigarette smoking or other use of tobacco or nicotine containing products within 3 months of screening 5. Diagnosed with any of the following disorders known to be associated with abnormal gastrointestinal motility such as; Gastroparesis, amyloidosis, neuromuscular diseases (including Parkinson's disease), collagen vascular diseases, alcoholism, uremia, malnutrition, or untreated hypothyroidism 6. History of surgery that alters the normal function of the gastrointestinal tract including, but not limited to: gastrointestinal bypass surgery, bariatric surgery, gastric banding, vagotomy, fundoplication, pyloroplasty \[Note: history of uncomplicated abdominal surgeries such as removal of an appendix more than 12 months prior to screening will not be excluded\] 7. Past or present : Organ transplant, chronic pancreatitis, pancreatic insufficiency, symptomatic biliary disease, Celiac disease, chronic constipation, diverticulosis, inflammatory bowel disease (IBD), ulcerative colitis (UC), Crohn's disease (CD), small intestine bacterial overgrowth syndrome (SIBO), gastroparesis, gastro-esophageal reflux disease (GERD), Irritable Bowel Syndrome (IBS) or any other medical condition with symptoms that could confound collection of adverse events. 8. Active ulcers, or history of severe ulcers 9. Diabetes mellitus (type 1 and type 2) 10. Congestive Heart Failure (CHF) 11. Human Immunodeficiency Virus (HIV), Hepatitis B or Hepatitis C 12. BMI \> 35 kg/m2 13. Recent bowel preparation for endoscopic or radiologic investigation within four weeks of screening (e.g., colonoscopy prep) 14. Use of concurrent therapy(ies) or other products (e.g., laxatives, stool softeners, Pepto Bismol®, Lactaid® Dietary Supplements) used for symptoms of lactose intolerance within 7 days of screening 15. Chronic antacid and/or PPI use 16. Recent use of systemic antibiotics defined as use within 30 days prior to screening 17. Recent high colonic enema, defined as use within 30 days prior to screening 18. Any concurrent disease or symptoms which may interfere with the assessment of the cardinal symptoms of lactose intolerance (i.e., gas, diarrhea, bloating, cramps, stomach pain) 19. History of ethanol (alcohol) and/or drug abuse in the past 12 months 20. Currently undergoing chemotherapy 21. Use of any investigational drug or participation in any investigational study within 30 days prior to screening 22. Prior enrollment in this study 23. Any other conditions/issues noted by the study staff and/or Principal Investigator that would impact participation and/or protocol compliance \-