Research Into Digestive System Issues

Pancreatic Insufficiency

The pancreas is attached to the small intestine behind your stomach and is crucial for proper digestion. Enzymes made by the pancreas are very important for getting nutrients, calories and vitamins into our bodies; they are the heart of proper digestion and absorption. In people with CF, sticky mucus blocks ducts in the pancreas and prevents enzymes from reaching the small intestine to digest food. This problem, called “pancreatic insufficiency,” affects about 90 percent of people with CF.

For more information on how the pancreas is affected in CF, read about the digestive system and learn more about research into CF-related diabetes.

Research Underway

We're funding research to develop a non-porcine enzyme replacement therapy with improved activity. This will offer an alternative to people with CF with pancreatic insufficiency who need to take enzymes.

In addition, we have 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 undergoes three years of training, develops best practices, and gains an improved understanding of abdominal symptoms to lead to better treatments.

The DIGEST has successfully trained both pediatric and adult gastroenterologists on the conditions associated with cystic fibrosis and there are now more than 65 physicians with this training across the United States. Members of the group have led several multicenter research projects on problems unique to CF GI disease, including studies on:

The symptoms in people with CF
Fecal testing for colon cancer
The impact of nutrition on respiratory health

They also have created a developing program to examine gastroesophageal reflux and the impact on pulmonary function.

DIGEST physicians have also prepared many guidelines and educational pieces for the CF Foundation.

Two studies are looking into the nutritional status of people with CF. In STRONG-CF, researchers hope to better understand the overall nutritional status and body composition of people with CF. They also want to know what psychosocial or other medical issues may contribute to malnutrition in the adult advanced lung disease population. This information will provide a starting point for future studies. The EATN study, a sister study to STRONG-CF, aims to evaluate the behavioral and psychosocial factors that support or hinder nutrition, strategies to improve nutritional status, and the acceptability and feasibility of assessments used in STRONG-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 nutrition and gastrointestinal (GI) issues.

Current Treatments

Some medications are available to help relieve the various symptoms associated with pancreatic insufficiency.

Cystic Fibrosis-Associated Liver Complications

People with CF also can experience complications that affect the liver. Liver problems for people with CF can range from mild abnormalities in liver blood tests (common) to advanced scarring of the liver and complications (in 7-10% of people with CF), such as a large spleen, bleeding from the esophagus and accumulation of fluid in the abdomen.

For more information on how the liver is affected in CF, read about the digestive system or watch “Understanding the Complexities of Liver Disease and CF” from ResearchCon 2024:

Research Underway

Because liver complications are difficult to identify in their early stages, doctors need better methods to diagnose problems in time to minimize liver damage and prevent complications related to CF-associated liver disease (CFLD). The Cystic Fibrosis Liver Disease Network, an innovative collaboration between the CF Foundation and the National Institute of Diabetes and Digestive and Kidney Diseases, conducted several studies investigating the best methods of screening for the presence of liver disease:

In the PUSH study, researchers found that children with CF who have a patchy pattern of the liver on a research ultrasound, called heterogeneous, had a 1 in 3 chance of developing advanced CFLD. They caution that the study required dedicated radiologists, and they are researching whether routine clinical ultrasound can perform the same way.
The ELASTIC study investigated a noninvasive method to identify scarring in the liver. They found that liver stiffness measured by elastography — non-invasive specialized medical imaging — can help identify advanced CFLD.
Another study using MRI and elastography also found that these tests can help identify individuals with CF who have advanced liver disease.

Other CF Foundation-sponsored studies are evaluating the impact (positive or negative) of CFTR modulators on the liver:

In the PROMISE and BEGIN studies, researchers are using routine ultrasound, elastography, and blood tests to study whether Trikafta (elexacaftor/tezacaftor/ivacaftor) can reduce or prevent scarring in the liver. To date, some liver blood tests improve, however, Trikafta does not seem to improve liver scarring.
In the RETRIAL study, researchers are exploring whether individuals with CF who have stopped Trikafta because of liver abnormalities can tolerate the newer modulator Alyftrek (vanzacaftor/tezacaftor/deutivacaftor).

In 2024, the Foundation published updated Liver Disease Clinical Care Guidelines. The new guidelines include recommendations and guidance for screening, monitoring, and treating liver disease in people with CF.

Current Treatments

People with advanced CFLD do not have many treatment options, but a multidisciplinary approach that includes the CF care center team is recommended in clinical care guidelines. The team will determine the causes of specific liver abnormalities and treat them accordingly. This treatment can include nutritional therapy and closer monitoring for complications as well as medications that may help treat those complications.

Colorectal Cancer

Colorectal cancer is a cancer that begins in the colon or rectum. Adults with CF have a 5-10 times greater risk of colorectal cancer than the general population and a 25-30 times greater risk after an organ transplant.

Although we do not know for certain why people with CF have a greater risk of developing colorectal cancer, it is thought to be associated with the CFTR gene mutation. In general, transplant recipients have an increased risk for all types of cancer because the medications they must take to prevent rejection weaken the immune system.

Research Underway

Research is being conducted to understand the mechanism — or the underlying process — that causes this higher risk. In the meantime, the Foundation convened a multidisciplinary team of experts to develop colorectal cancer screening recommendations.

To encourage more people with CF to get screened, the NICE-CF study is looking at the use of stool-based testing, a non-invasive option, to understand who would benefit from further testing by undergoing a colonoscopy.