Microbiome research in autoimmune and immune-mediated inflammatory diseases: lessons, advances and unmet needs

The increasing prevalence of autoimmune and immune-mediated diseases (AIMDs) underscores the need to understand environmental factors that contribute to their pathogenesis, with the microbiome emerging as a key player. Despite significant advancements in understanding how the microbiome influences physiological and inflammatory responses, translating these findings into clinical practice remains challenging. This viewpoint reviews the progress and obstacles in microbiome research related to AIMDs, examining molecular techniques that enhance our understanding of microbial contributions to disease. We discuss significant discoveries linking specific taxa and metabolites to diseases such as rheumatoid arthritis, systemic lupus erythematosus and spondyloarthritis, highlighting the role of gut dysbiosis and host–microbiome interactions. Furthermore, we explore the potential of microbiome-based therapeutics, including faecal microbiota transplantation and pharmacomicrobiomics, while addressing the challenges of identifying robust microbial targets. We advocate for integrative, transdisease studies and emphasise the need for diverse cohort research to generalise findings across populations. Understanding the microbiome's role in AIMDs will pave the way for personalised medicine and innovative therapeutic strategies.