Nutrition and CFTR modulators

This information is for people living with cystic fibrosis (CF) and includes information about nutrition while on highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulators, for example, Trikafta.

What changes could I see when I am on a CFTR modulator?

Many people have seen changes such as:
• Easier to smell and taste food
• Better appetite
• Easier to gain weight
• Less belly aches
• Less heartburn or reflux
• Less smelly or greasy poops (better digestion and absorption of food)

How can I prevent constipation?

Many people get constipated when they first start on a CFTR modulator. This happens because the medication helps the thick sticky mucus move through and out of your gut. It usually goes away after the first few days of treatment and can often be prevented.

Tips to prevent constipation:
• Drink more fluids (water, milk, juice, electrolyte drinks)
• Use a stool softener such as PEG 3350 (Restoralax/ Lax-a-Day or another medication) as instructed by your CF team for a few days before starting on your CFTR modulator
• Increase your activity (walk around more) to help move the stool and mucus • Increase fibre intake (eg. Fresh fruits (eg kiwi, berries), vegetables (eg carrots, peas, zucchini), whole grain breads and cereals, and lentils, beans, chick peas)

Will I need to keep taking my enzymes and vitamins?

Yes. Do not change any of your CF treatments, medications or vitamins without talking to your CF team first. Your blood can be checked to see if your vitamin doses can be changed. A reduction in frequency of vitamin therapy may be recommended. Check with your dietitian. Your stool (poop) can be checked to see if your enzyme dose can be changed.

Will there be a change in my need to check blood sugars?

If you are checking your blood sugars, continue to do so, and discuss with your team about your blood sugar levels and your insulin dose, as they will best guide you on any changes needed.

What if I think I am gaining weight too fast?

Everyone feels differently about their body changing. It is important to talk to your CF dietitian to discuss healthy eating options that are right for you. If you are at or above your healthy weight, your CF dietitian may suggest the following diet changes:

What foods can I take my CFTR modulator with?

You need at least 5 grams of fat (some people need closer to 10g) to absorb these medications.

Please do not hesitate to reach out to your clinic team members if you have concerns and need more support around your weight or have body image concerns.