A new study reported in Nature Medicine has identified strains of the fungus Candida moving from the mouth into the gut in people with inflammatory bowel disease (IBD), according to research discussed by Iliyan D. Iliev, PhD, of Weill Cornell Medicine. The findings add to growing evidence that the oral and intestinal microbiomes are more closely connected than previously understood, with potential implications for how clinicians think about disease flares and gut inflammation.
Background Context
IBD, which includes Crohn’s disease and ulcerative colitis, is increasingly understood as arising from a combination of genetic susceptibility, immune dysregulation and environmental exposures, collectively described in recent literature as the “exposome”. Alongside bacterial populations, fungal communities within the gut, known as the mycobiome, have drawn growing research interest for their possible role in sustaining inflammation. Separately, other recent work has examined whether changes in gut microbiome composition can be detected before Crohn’s disease develops in people who are already at higher risk, such as first-degree relatives of existing patients, suggesting that microbial shifts may precede clinical symptoms rather than simply follow them.
Key Findings
According to Iliev, speaking to HCPLive, a prospective observational study found that specific strains of Candida normally residing in the mouth were detected translocating into the gut microbiome of people with IBD. This suggests the oral cavity may act as a reservoir from which fungal organisms can seed or reinforce populations within the intestine. Iliev, who co-directs the microbiome core laboratory at the Jill Roberts Institute, explained that this transfer appears distinct from normal microbial exchange, occurring in a manner associated with the inflamed gut environment characteristic of IBD. The observational design allowed researchers to track fungal strains over time rather than relying on a single snapshot, strengthening confidence that the mouth-to-gut movement reflects a genuine biological pathway rather than incidental contamination. The study forms part of a broader body of research examining how fungal, as well as bacterial, communities interact with the immune system in people living with Crohn’s disease and ulcerative colitis.
Clinical Relevance
For clinicians and researchers working in IBD, these findings reinforce the idea that gut inflammation cannot be fully understood by looking at intestinal bacteria alone. If oral fungal strains are indeed capable of establishing themselves in the gut during disease, this raises questions about whether oral health and the composition of the mouth microbiome could influence intestinal disease activity. The research does not indicate any need for patients to alter their current treatment or oral hygiene practices, but it does highlight a potential new avenue for understanding what sustains inflammation in some people with IBD, and where future microbiome-focused research and diagnostics might be directed.
Reference
Iliev ID. How Candida moves from mouth to gut in IBD [interview]. HCPLive. Available from: https://www.hcplive.com/view/how-candida-moves-from-mouth-to-gut-in-ibd-with-iliyan-d-iliev-phd
This article is a journalistic summary for informational purposes only. It does not constitute clinical advice or a recommendation to alter treatment decisions.