Persons with dairy intolerance may experience cramps/abdominal pain, bloating, flatulence, acute diarrhea, or fecal urgency when they ingest excessive amounts of lactose. The intensity of these conditions can be mild or severe and likely depends on numerous variables including dose, transit time, intestinal residual lactase activity and microbiome potential to ferment lactose. Jersey cattle produce milk containing high levels of the A2 β-casein protein . There are claims that high A2 β-casein milk is more easily digested by people who are lactose maldigesters . We propose to conduct a double-blinded, randomized, controlled trial to determine if high A2 β-casein milk from Jersey cattle is actually better digested and tolerated by lactose maldigesters.~This proposed protocol comparing the dairy intolerance symptoms from milks containing predominantly the A1 variant versus A2 variant will establish if high A2 milk is better digested and/or tolerated than high A1 milk.~Participants will be asked to consume four different commercially available milks in random order. The samples will be fed for breakfast separated by at least 10 days, after overnight fasts. The commercial milk treatments will include; high A1 β-casein milk (commercial milk), high A2 β-casein milk, Jersey cattle milk (which contains a mixture of A1 and A2 β-casein), and a lactose free milk control. Milk will be 2% fat content to control for transit. Each subject will be fed milk containing 0.5g lactose per kg body weight. There will be two arms in this study: dairy intolerant who are lactose maldigesters, and dairy intolerant who are lactose digesters.
Persons with dairy intolerance may experience cramps/abdominal pain, bloating, flatulence, acute diarrhea, or fecal urgency when they ingest excessive amounts of lactose. The intensity of these conditions can be mild or severe and likely depends on numerous variables including dose, transit time, intestinal residual lactase activity and microbiome potential to ferment lactose. Jersey cattle produce milk containing high levels of the A2 β-casein protein . There are claims that high A2 β-casein milk is more easily digested by people who are lactose maldigesters . We propose to conduct a double-blinded, randomized, controlled trial to determine if high A2 β-casein milk from Jersey cattle is actually better digested and tolerated by lactose maldigesters.