Research

Some examples of my research and the impact it has had.

Feargal Ryan standing beside the Sharing Systems mural at the Women's and Children's Hospital, Adelaide, a painted tree with a trunk made of coloured research-data squares
With the mural, August 2026.
Research in the community

Sharing Systems

Sharing Systems, a new mural by South Australian artist Laura Wills at the Women's and Children's Hospital in Adelaide, weaves real data from our Nature study on Bifidobacteria and infant vaccine responses into its tree trunks, plants, birds and butterfly wings.

Created with hospital patients and students from Hospital School SA, it pictures a healthy ecosystem working together, much like the microbiome, and welcomes families at one of the hospital's main entrances.

About the muralThe Nature paper

Understanding variability in vaccine antibody and T cell responses

Why do some people respond strongly to vaccines and others don't? In infants, gut Bifidobacteria turn out to be essential for optimal responses to the PCV13 pneumococcal vaccine, and antibiotics given in the first days of life blunt those responses for up to seven months. In adults, a multi-omics atlas of the immune system compared innate and adaptive responses to mRNA and adenovirus-vectored COVID-19 vaccines.

ImpactA world-first probiotic trial now underway in South Australia; Research Highlights in Nature Reviews Microbiology and Nature Reviews Immunology.

Molecular mechanisms of long COVID

Some of the earliest molecular evidence for long COVID: immune gene-expression signatures that persist months after SARS-CoV-2 infection, and trace-level cytokines that impair heart muscle cell function.

ImpactCited in NICE's COVID-19 guidance documents (UK); Altmetric score of 872, in the top 1% of research outputs.

Precision medicine for IBD

Multi-omic profiling of more than 850 patients across Ireland and North America, with over 340 biopsies. It showed that the microbiome modulates inflammation through epigenetic mechanisms and that medication drives much of the variation.

ImpactCited in German national IBD guidelines (AWMF); led to a data-licensing collaboration with Second Genome Inc.

For every paper, see Publications.