The pancreas has tissue that makes digestive enzymes. The enzymes move from the tissue through a duct (tube), mixing with a bicarbonate-rich fluid that is produced in the duct. The enzymes and the fluid flow into the small intestine where the bicarbonate neutralizes stomach acid and the enzymes digest food. The fluid also hydrates the intestines. In most people with cystic fibrosis, this process is affected in the following ways:
Cystic fibrosis transmembrane conductance regulator (CFTR) proteins in the duct don't work properly, affecting the amount of fluid and bicarbonate that is produced. This lack of fluid causes the duct to become blocked. When this happens, the powerful enzymes that normally digest food back up into the pancreas and destroy the tissue.
- When enzymes can't get into the small intestine, food is not broken down properly. For this reason, most people with CF cannot absorb the nutrients they need, and they can become malnourished. About 90 percent of people with CF have this problem, called “pancreatic insufficiency,” and need to take enzymes with every meal and snack to properly digest food.
- About 10 percent of people with CF are “pancreatic sufficient,” which means they have enough CFTR protein function in the pancreatic duct that they do not need to take enzymes. However, they are still prone to blockages in the duct, which cause enzymes to back up and damage tissue, causing pancreatitis.
- All people with CF have trouble making enough fluid and bicarbonate, which can lead to pain, cramping, gas, and constipation.
The Cystic Fibrosis Foundation has helped organize a group of gastrointestinal (GI) specialists to focus on the treatment and research of GI issues in CF. Called the Developing Innovative Gastroenterology Specialty Training program, or DIGEST, this group of GI doctors is developing best practices and gaining an improved understanding of abdominal symptoms to lead to better treatments.
Additionally, the CF Foundation is supporting clinical trials to test the effects of oral glutathione, an antioxidant that is important to the normal functioning of the intestine and lungs. Glutathione levels have been shown to be lower in people with CF. Oral glutathione may improve growth and decrease digestive inflammation in children with CF.
In this video, Meghana N. Sathe, M.D., associate professor of pediatrics and co-director of the pediatric CF center at the University of Texas Southwestern Medical Center/Children's Health, explains why people with CF can have problems with getting proper nutrition and experience gastrointestinal (GI) issues. She also discusses the GI Wellness study (now called the GALAXY study), which is being conducted by DIGEST doctors to gauge which GI symptoms affect people with CF the most, so that researchers can prioritize them for further study.
To relieve the various symptoms associated with pancreatic insufficiency, people with CF can take various medications.