In the Journals

Baker's yeast linked to worsening of symptoms in Crohn's disease

Recent study data suggest that the common yeast strain Saccharomyces cerevisiae, also known as Baker’s yeast, may exacerbate Crohn’s disease symptoms.

Investigators concluded that allopurinol, a generic drug used to reduce uric acid in patients with gout, could be used to counter this effect.

While Crohn’s disease is associated with an increase in antibodies against S. cerevisiae, the role that this yeast plays in inflammatory bowel disease is unclear.

“To me this was a huge hole in our understanding of the role of yeast in IBD and our health,” June Round, PhD, associate professor in pathology at the University of Utah School of Medicine, said in a press release.

She and colleagues therefore evaluated the effects of S. cerevisiae and Rhodotorula aurantiaca — another yeast strain commonly found in the human gut microbiome — in a mouse model of colitis. They found that S. cerevisiae exacerbated intestinal disease and increased gut barrier permeability, while R. aurantiaca did not.

“The mice fed S. cerevisiae experienced significant weight loss, diarrhea, bloody stool, just like a person with IBD,” Tyson Chiaro, MS, a graduate student in Round’s lab, said in the press release.

Analysis of fecal metabolomics showed that the mice who were colonized with S. cerevisiae had higher concentrations of purines, which the yeast strain is unable to break down in the GI tract, and this led to increased production of inflammatory uric acid.

Round and colleagues then confirmed the link between S. cerevisiae and uric acid levels by evaluating human blood samples from 168 healthy volunteers.

“We found that every human serum sample with high S. cerevisiae antibodies also had high uric acid levels,” she said in the press release.

Finally, the investigators showed that treating the mice with uric acid worsened intestinal disease and increased gut permeability, while treating them with allopurinol to reduce uric acid levels significantly reduced their intestinal inflammation.

“Our work suggests that if we can block the mechanism leading to the production of uric acid, perhaps with allopurinol, IBD patients with a high concentration of S. cerevisiae antibodies may have a new treatment option to reduce inflammation, which could allow the intestine time to heal,” Round said in the press release.

She and colleagues plan to further study the interactions of gut bacteria and yeast and the role they may play in certain diseases.

“Yeast and bacteria might influence the biology of one another within our gut. Yet, we have no idea how that interaction effects human disease,” she said in the press release. “Our research will continue to explore the role intestinal micro-organisms play in our health with the hopes of identifying microbiota-based therapies to treat different diseases.” – by Adam Leitenberger

Disclosures: The researchers report no relevant financial disclosures.

Recent study data suggest that the common yeast strain Saccharomyces cerevisiae, also known as Baker’s yeast, may exacerbate Crohn’s disease symptoms.

Investigators concluded that allopurinol, a generic drug used to reduce uric acid in patients with gout, could be used to counter this effect.

While Crohn’s disease is associated with an increase in antibodies against S. cerevisiae, the role that this yeast plays in inflammatory bowel disease is unclear.

“To me this was a huge hole in our understanding of the role of yeast in IBD and our health,” June Round, PhD, associate professor in pathology at the University of Utah School of Medicine, said in a press release.

She and colleagues therefore evaluated the effects of S. cerevisiae and Rhodotorula aurantiaca — another yeast strain commonly found in the human gut microbiome — in a mouse model of colitis. They found that S. cerevisiae exacerbated intestinal disease and increased gut barrier permeability, while R. aurantiaca did not.

“The mice fed S. cerevisiae experienced significant weight loss, diarrhea, bloody stool, just like a person with IBD,” Tyson Chiaro, MS, a graduate student in Round’s lab, said in the press release.

Analysis of fecal metabolomics showed that the mice who were colonized with S. cerevisiae had higher concentrations of purines, which the yeast strain is unable to break down in the GI tract, and this led to increased production of inflammatory uric acid.

Round and colleagues then confirmed the link between S. cerevisiae and uric acid levels by evaluating human blood samples from 168 healthy volunteers.

“We found that every human serum sample with high S. cerevisiae antibodies also had high uric acid levels,” she said in the press release.

Finally, the investigators showed that treating the mice with uric acid worsened intestinal disease and increased gut permeability, while treating them with allopurinol to reduce uric acid levels significantly reduced their intestinal inflammation.

“Our work suggests that if we can block the mechanism leading to the production of uric acid, perhaps with allopurinol, IBD patients with a high concentration of S. cerevisiae antibodies may have a new treatment option to reduce inflammation, which could allow the intestine time to heal,” Round said in the press release.

She and colleagues plan to further study the interactions of gut bacteria and yeast and the role they may play in certain diseases.

“Yeast and bacteria might influence the biology of one another within our gut. Yet, we have no idea how that interaction effects human disease,” she said in the press release. “Our research will continue to explore the role intestinal micro-organisms play in our health with the hopes of identifying microbiota-based therapies to treat different diseases.” – by Adam Leitenberger

Disclosures: The researchers report no relevant financial disclosures.