Cystic fibrosis care expands beyond lungs as gut risks grow

Cystic fibrosis is often treated in public understanding as a lung condition, but researcher Chee Y. Ooi writes in The Conversation that the disease also affects the digestive tract, pancreas and liver. That matters because people with cystic fibrosis are living longer, making gastrointestinal complications a larger part of care.

Ooi describes cystic fibrosis as a genetic disease caused by mutations in the CFTR gene. That gene normally produces a protein that helps move water and other material across organ surfaces, keeping mucus and secretions fluid enough to move through ducts and tissues.

When the protein does not work properly, Ooi writes, mucus and secretions become thick and sticky. They can block organs and ducts and can be colonized by harmful microbes in the lungs and gut, triggering inflammation.

Gut signs can appear early

According to Ooi, digestive problems in cystic fibrosis can begin before birth. The condition may be suspected during antenatal scans that show bowel changes, or at birth when a baby has signs of bowel obstruction.

Ooi writes that, historically, some children with cystic fibrosis died from pancreatic and intestinal complications before severe lung disease developed. As survival has improved, bowel obstruction, severe constipation, abdominal pain, reflux and nausea have become more visible as ongoing health problems.

These symptoms can affect people with cystic fibrosis at any age, Ooi writes, and can reduce quality of life. He also notes that some health professionals still give less priority to digestive symptoms because lung disease has long dominated cystic fibrosis care.

Longer survival changes the risks

Cystic Fibrosis Australia registry data cited by Ooi say about 3,800 Australians live with cystic fibrosis. In countries with newborn screening, including Australia, most cases are now found through heel-prick blood testing in infancy, though milder cases or rare mutations may be diagnosed later.

Ooi writes that cystic fibrosis is the most common life-threatening genetic disease of its kind in white populations, but he rejects the idea that it affects only white people. He says underdiagnosis is likely in some regions and argues that the Indian subcontinent may have many undetected cases.

Survival has changed sharply, according to data Ooi cites. He writes that most children with cystic fibrosis once did not live into adulthood, while current Australian data show more adults than children living with the condition, at 60% compared with 40%.

For people born in 2019 through 2023, the predicted survival age is 64 years, according to registry figures cited by Ooi. He attributes longer life expectancy to newborn screening, earlier nutritional and lung care, and newer medicines known as CFTR modulators.

Treatments have limits

CFTR modulators can restore some function of the defective CFTR protein, Ooi writes, and many patients have had major gains in lung function. He cautions that the drugs are not a cure, do not erase existing organ damage and are not suitable for everyone.

The digestive benefits have been less pronounced so far, according to Ooi. When the drugs start in early childhood, they can partly improve pancreatic function, but gastrointestinal symptoms, advanced liver disease and gastrointestinal cancer risks can remain.

Ooi writes that adults with cystic fibrosis face higher rates of gastrointestinal cancers, including colorectal cancer, and may be diagnosed younger than the general population. He says those risks have been known for decades but drew less attention when fewer patients survived to ages when cancers became a major concern.

Researchers are now studying diet, gut inflammation and the gut microbiome in cystic fibrosis, according to Ooi. His central point is that care must account for the whole body as longer survival makes digestive health a continuing priority.

This story draws on original reporting from Medical Xpress.