Alterations to the gut microbiota in humans are associated with symptomatic atherosclerosis and stroke, say researchers.
Writing in Nature Communications, the Swedish research team noted that recent findings have suggested that the type of bacteria in the gut could contribute to the risk of metabolic diseases by altering levels of inflammation and changing metabolic pathways.
The team compared a group of stroke patients with a group of healthy subjects and found major differences in their gut microbiota.
“We use shotgun sequencing of the gut metagenome to demonstrate that the genus Collinsella was enriched in patients with symptomatic atherosclerosis, … whereas Roseburia and Eubacterium were enriched in healthy controls,” wrote the researchers, led by Professor Jens Nielsen, of Chalmers University of Technology.
In addition the team found that genes required for the production of carotenoids were more frequently found in gut microbiota from healthy subjects, while healthy subjects also had significantly higher levels of beta-carotene in the blood than the stroke survivors.
“Our findings suggest that the gut metagenome is associated with the inflammatory status of the host and patients with symptomatic atherosclerosis harbour characteristic changes in the gut metagenome,” said Nielsen and his colleagues.
“Even though our study cannot provide evidence for direct causal effects, these findings indicate that the gut metagenome may have a role in the development of symptomatic atherosclerosis.”
"Our results [also] indicate that long-term exposure to carotenoids, through production by the bacteria in the digestive system, has important health benefits,” said Nielsen.
“These results should make it possible to develop new probiotics,” he added. “We think that the bacterial species in the probiotics would establish themselves as a permanent culture in the gut and have a long-term effect."
The researchers behind the findings have now started a company, Metabogen, to further develop their discoveries relating to the metagenome.