They help regulate the levels of blood glucose, or sugar, in your body.
The only way anyone is able to know exactly what is in a product is to either do a lot of studying on the matter of read the nutrition label. Be warned however, because while companies are not allowed to falsify information on the label, they can mislead people by splitting up a package into servings or requiring a separate ingredient.
They are much less likely to develop the disease a second time.
Memory B cells help your body prevent getting sick a second time once you get sick the first time. So for instance it may take about 15-16 days for your memory B cells to produce enough antibodies against this certain pathogen the first time, however once you get sick with the same thing the second time, these memory B cells will kick in and will take less time to fight off the pathogens in like 5 days. :)
Lymphatics and immune system is very important to study :) hah
Good luck and I hope this has helped you! :D