4. Discussion
milk, New-World milk, lactose intolerance, gastrointestinal and colonic transit
LACTOSE INTOLERANCE
No previously reported studies have compared the gastric emptying time of milk containing A1 and A2 β-casein with milk containing only A2 β-casein. Therefore, this pilot study could be used for power calculations for larger-scale studies. We planned to recruit 10 subjects to examine a difference in transit. We completed the trial after we collected data from all 10 participants. While the sample size is modest, the differences in gastric transit are highly significant and biologically relevant. We suggest that the gastric transit of New-World milk containing both A1 and A2 β-casein is more rapid as compared to Old-World milk containing only A2 β-casein. Jianqin et. al. reported a slower total gastrointestinal and colonic transit of milk containing A1 β-casein in comparison to A2 milk [Slow gastric emptying is associated with better tolerance and digestion among maldigesters [We did not stratify subjects based on age, gender or race because evidence suggests that lactose intolerance does not depend on demographics but on the dose and differences in the lactase non-persistent gene [The nutrient composition of conventional milk and A2 milk were very similar. The slight difference in fat could account for some of the difference in transit [