2.4. Biological Material
Fasting venous blood
STERILE
Fasting venous blood was collected by qualified nurses (20 mL) in the morning, between 8:00 and 11:00 a.m., after overnight rest. One sample was collected at the beginning of the intervention period (V1) and another at the end (V2). The blood serum was frozen for future analyses. Stool samples were self-collected by study participants and were given to study investigators on the same or the next day after in-person meetings. Participants were given specific sterile containers for stool samples. If it was not possible to give the samples to study investigators within one hour of collection, the stool was to be kept frozen in any available freezer until the next day.