IBD Science for Patients

If you’re taking powerful, advanced medicines for your Crohn’s or colitis, it’s completely natural to worry about how your immune system will handle everyday viruses. Many of us are told that these treatments make us “immunosuppressed” (meaning our body’s natural defence force is toned down). This often leaves patients feeling vulnerable every time a cold, flu, or coronavirus wave comes around.

However, a new clinical study published in Aug 2026 brings incredibly reassuring news. The research reveals that advanced therapies do not actually increase your risk of catching common respiratory viruses. Instead, the real culprit behind weakened viral defences is a much older, more common drug: prednisolone.

The Truth About Your IBD Meds and Cold Viruses

To find out how IBD treatments affect your risk of catching a bug, a team of researchers at the Mater Hospital Brisbane in Australia conducted a medium-sized retrospective study. This is a type of study where scientists look back at historical medical records over a set timeframe to spot patterns.

The team analysed the records of 184 patients with IBD who reported 288 different episodes of respiratory symptoms, such as a sore throat, cough, or runny nose, between February 2020 and September 2023. This means the study ran for over three and a half years, capturing data during major winter flu seasons and the peak of the pandemic.

Whenever these patients fell ill, doctors used a PCR (Polymerase Chain Reaction) swab test. This is a highly accurate laboratory technology that copies tiny bits of viral genetic material from a throat or nose swab to identify exactly which virus is present.

The results were eye-opening:

• No Extra Risk from Advanced Therapies: Patients taking advanced biologic treatments (such as infliximab, adalimumab, vedolizumab, or ustekinumab) or standard immunomodulators were no more likely to test positive for a virus than those not taking them.
• The Prednisolone Spike: Patients taking prednisolone (a common steroid used to quickly calm down flare-ups) were nearly three times more likely to have an active virus detected in their swabs.

Why This Matters to You as a Patient

If you’re managing ulcerative colitis or Crohn’s disease, this study is a vital guide for your journey toward health:

1. Freedom from Biologic Fear: This study gives you the scientific proof that you do not need to live in constant fear of everyday germs just because you are on a modern biologic treatment. Your advanced therapies are highly targeted, meaning they calm the inflammation in your gut without leaving your lungs completely defenceless.
2. Rethinking Steroid Use: While steroids like prednisolone are excellent at stopping a severe flare-up in its tracks, they act like a broad “blanket” that dampens your entire immune system. This research highlights why it is so important for you to work with your doctor to reduce your steroid exposure.
3. Prioritising ‘Steroid-Sparing’ Plans: The best way to protect yourself from both gut flares and winter viruses is to stay in stable remission. By starting advanced, steroid-sparing therapies earlier, you can avoid the need for repeat steroid prescriptions, keeping your gut healthy and your lungs protected.

While practising good hygiene and staying up-to-date with seasonal vaccines remain important, you can rest assured that your advanced IBD medications are not the open door to winter bugs that we’ve spent many years believing they are.