Gut microbiome

The gut microbiome is a complex microbial community that functions as an exposure set and modulator of host physiology, especially immune function and immunotherapy outcomes. In the provided Mendelian randomization analysis, 207 gut microbiota were selected as exposures and 7 were causally associated with aortic stenosis, highlighting a potential causal role beyond correlation. It is strongly linked to ici colitis and is also implicated in responses to immune checkpoint inhibitors, where specific community compositions can significantly alter treatment outcomes. The microbiome can be therapeutically reshaped through dietary modulation, fecal microbiota transplantation, and probiotic supplementation, making it a practical target for intervention. Recent literature also frames it as a key factor in cancer immunotherapy, including urothelial carcinoma, and in immune-related adverse events.

Cardiovascular disease

  • A multi-omics Mendelian randomization study found that 207 gut microbiota were analyzed as exposures, with 7 showing causal association with aortic stenosis (PMID:41961656).
  • The same study linked the gut microbiome to plasma metabolites and inflammation in the context of aortic stenosis, supporting a mechanistic role in disease biology (PMID:41961656).

Cancer immunotherapy and immune toxicity

  • The gut microbiome was described as strongly associated with ici colitis, a major immune-related adverse event in cancer immunotherapy (PMID:41992000).
  • A 2026 Nature Reviews Cancer article emphasized microbiota as a determinant of immune-related adverse events during immunotherapy (PMID:41992000).
  • Specific gut microbiome compositions were reported to significantly modulate response to immune checkpoint inhibitors (PMID:41560593).
  • A 2026 Oncoimmunology review highlighted lessons from manipulating the gut microbiome to improve immunotherapy for urothelial carcinoma (PMID:41560593).

Microbiome modulation strategies