Researchers studied Saccharomyces boulardii (Sb), the only yeast species already used as a probiotic, because its behaviour in the gut is not well known. For the experiments they used an off-the-shelf strain that had not been genetically modified.
The team introduced Sb into germ-free mice, which are mice with no gut microbes, and collected fecal and intestinal samples. They used a novel combination of established sampling and analytical techniques to measure the RNA that the yeast produced as it passed through the mice.
They identified genes that become more active in the gut, including promoter regions that act as on-switches. The yeast did not activate genes linked to harmful behaviour, which supports its safety for further engineering work.
Difficult words
- probiotic — a live organism used to improve gut health
- strain — a specific type or version of an organism
- germ-free — without any living microbes or bacteriagerm-free mice
- microbe — a very small living organism, like bacteriamicrobes
- ribonucleic acid — a molecule that carries genetic informationRNA
- promoter — a DNA part that starts gene activitypromoter regions
- fecal — related to waste material from the intestine
- intestinal — connected to the inside of the digestive tract
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Do you think probiotics are useful? Why or why not?
- Would you try a probiotic product that contains yeast? Explain briefly.
- Why is it important that the yeast did not activate harmful genes?
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