This is a multicentre, phase I/II, double-blind, placebo-controlled study of MRx-4DP0004 in
participants taking long-term medication for asthma. Participants will take two capsules of
MRx-4DP0004 twice daily in addition to their existing asthma medication for 12 weeks. Safety
and tolerability and immune modulatory effects of MRx-4DP0004 will be assessed throughout the
study.