Milk Consumption on Digestive Comfort.
Condition: Healthy Volunteers
Study type: Interventional

Summary: 
      Lactose, naturally present in milk, can cause digestive discomfort. Delactosed milk is
      currently the only one alternative to cow's milk for intolerant people. As some of them do
      not digest milk, it was completely remove from their diet. However, are they really
      intolerant to lactose or intolerant to milk (or to another of its compounds)? Do β-caseins
      play a role in this intolerance? β-caseins are proteins naturally present in milk. Two types
      of β-caseins were identified: A1 and A2. These types differ according to the genetic profile
      of the cow and depend on the breed. The rare clinical studies interested in this topic
      suggest that:

        1. consumption of milk A1 versus consumption of milk A2 can lead to: softer stools, delayed
           transit, as well as pro-inflammatory effects in some individuals,

        2. consumption of A2 milk significantly reduces gastrointestinal symptoms and improves
           digestive comfort in lactose intolerant people.

      Thus, it would be interesting to be able to assess the effect of a consumption of A2A2 milk
      type compared to A1A2 milk type, both on the parameters of digestive comfort and on
      inflammatory parameters.
    

Detailed description: 
      The study will be carried out on healthy volunteers, aged 18 to 65 and self-declared
      sensitive, even intolerant to the consumption of milk.

      The main objective of the study is to assess the impact of milk β-caseins (A2A2 vs A1A2) on
      the digestive comfort felt during the consumption of milk in subjects declaring that they do
      not tolerate milk.
    

Intervention name(s): Group (A1 → A2); Group (A2 → A1)
Intervention type(s): Other; Other
Intervention description(s): Before each start of consumption of the products under study, a wash-out period of 2 weeks (no consumption of milk) must be observed by the subjects.
25 subjects will consume A1A2 milk for 2 weeks (period 1), then they will consume A2A2 milk for 2 weeks (period 2).
During each consumption period, various questionnaires will be completed by the subjects: frequency and consistency of stool, analog visual scales on digestive comfort and dietary surveys. Stool collections will also be carried out.; Before each start of consumption of the products under study, a wash-out period of 2 weeks (no consumption of milk) must be observed by the subjects.
25 subjects will consume A2A2 milk for 2 weeks (period 1), then they will consume A1A2 milk for 2 weeks (period 2).
During each consumption period, various questionnaires will be completed by the subjects: frequency and consistency of stool, analog visual scales on digestive comfort and dietary surveys. Stool collections will also be carried out.
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: monocentric, double-blind, randomized, controlled, cross-over and ambulatory study
Masking: Double (Participant, Investigator)
Primary purpose: Other
Keywords: milk intolerant; β-caseins A1 and A2; Lactose