Darrel B. is a 56-year-old male who was diagnosed with pancreatic cancer two months ago. Because Darrel's cancer has not spread beyond the local tissue of the pancreas, his doctor informs him that he is eligible for surgery to remove the tumor through a Whipple procedure. Darrel undergoes surgery, where his surgeon removes the head of the pancreas, the gall bladder, part of the common bile duct, most of the duodenum, and part of the stomach. The surgeon then connects the remaining portion of the pancreas so that pancreatic enzymes, bile, and the contents from Darrel's stomach will flow directly into the small intestine. Darrel's doctors are confident that the surgery has been successful in removing all of the pancreatic tumor, but emphasizes that he has a long road of recovery after having such a complex surgical procedure. Since a portion of the duodenum was removed during the procedure, Darrel is now missing various elements normally found in the mucosal lining of this portion of the small intestine, including Brunner's glands. What is the function of Brunner's glands in the duodenum