Development Of An Innovative Panel of Methods To Measure Intestinal Macronutrient Digestion, Absorption, and Function

Malnutrition is a significant problem in children and adults with Cystic fibrosis (CF). An
impaired intestinal digestion and absorption capacity is one of the main factors responsible
for the malnutrition in CF. This impairment starts early in life, leading to malnutrition,
muscle weakness, impaired immune and lung function associated with poor prognosis. As low BMI
and body weight is strongly associated with morbidity and mortality, a reduction in weight
loss in CF and its manifestations would save the healthcare system substantially per year.
Simple methods to measure the digested portions and utilization of nutrients and the
effectiveness of pancreatic enzyme preparations and medications in CF are not available.
Developing a panel of methods to accurately measure gut digestion, absorption and function
will lead to studies optimizing nutritional regimen and pancreatic enzyme replacement therapy
in CF. Furthermore, it will provide detailed insight in the disease and age related
mechanisms of gut dysfunction in CF. Finally, it will provide required information that will
lead to implement new strategies to improve gut health in order to enhance nutritional
status, quality of life and survival.

The hypothesis is that intestinal macronutrient digestion, absorption and function in CF can
be quantified by an innovative panel of methods using stable isotopes. With this panel of
methods, information can be obtained on the effect of disease progression on lipid, protein
and glucose digestion and absorption and on gut function in CF as well as in other diseases
and conditions characterized by a compromised gut. Furthermore, the optimal nutritional
regimen and pancreatic enzyme therapy if applicable can be evaluated in these diseases. In
the present study the investigators will study: 1. Pediatric patients with CF at Arkansas
Children's Hospital; 2. Adult patients with CF at University of Arkansas for Medical
Sciences. 3. Healthy control subjects. Diagnosis of CF is made based on universal diagnostic
criteria. All CF patients are characterized by abnormal lipid digestion based on clinical and
or laboratory (72 hour fat analysis or fecal elastase measurement) diagnosis, and requiring
pancreatic enzyme replacement therapy, and no presence of unstable metabolic diseases.
Additional criteria for the CF pediatric inpatients are: admitted to ACH for treatment of
exacerbations of CF disease, clinically stable. The CF outpatients are stable outpatients
with pancreatic insufficiency.