SEP 14, 2019 10:29 AM PDT

Gut Microbes can Significantly Impact Host Gene Expression

WRITTEN BY: Carmen Leitch

We all carry a vast number of microbes with us, and the microbial community in the gut is closely linked to our health and well-being. The food we ingest, the medicines we take, the stuff we’re exposed to in our environment, and our genes can all affect the gut microbiome, which helps us digest food and absorb nutrients.

Since the rapid advance of various genetic technologies in recent times, researchers are learning more about the many microorganisms that are part of our microbiome. Scientists have also shown how dysfunction or imbalances in the gut microbiome have been connected to many different diseases, including disorders of the gut like Crohn’s or colorectal cancer, as well as autoimmune and mental disorders.

Now that we know how important the gut microbiome is, scientists want to know exactly which species are having what impact on different people. One way to do that is to model the microbiome and look at how it affects gene expression in a host.

New work reported in mSystems has done just that, in an effort to build on other research that has used mouse models to show that microbes of the gut can affect gene expression and modifiable genetic features called epigenetic markers, and human studies that link the composition of the microbiome with a physiological characteristic. Since it is difficult to research the microbiome directly in humans, the researchers created a model of the microbiome; their in vitro system consists of human colon cells grown in hypoxic conditions - mimicking the environment of the gut.

The researchers exposed the colon cells to gut flora that had been obtained from human fecal samples and assessed how gene expression changed in the ‘host’ colon cells by sequencing the active genes using RNA-seq. They found that the expression of more than 5,000 host genes changed after the cells were exposed to the microbes. They identified 588 distinct connections between specific microbial populations and host genes.

Bacteroides bacteria, which are mainly found in the intestine as normal flora. / Credit: CDC / Dr. V. R. Dowell, Jr.

The scientists identified several genes that were expressed differently depending on their exposure, some of these genes have been associated with obesity, and have been identified in similar mouse studies. They also looked at chromatin accessibility, which is believed to have a significant impact on gene expression; chromatin will only allow the transcription machinery to transcribe genes that are accessible. While the changes they saw were small, changes in chromatin accessibility due to the influence of the microbiome may be altering the expression of some genes.

The work also demonstrated that the addition of a single microbe could affect the microbiome in a predictable way, which agrees with other research indicating that microbes may one day be used in therapeutics.

The microbiome is having a significant effect on the expression of its host’s genes, but the mechanisms by which the microbiome is doing so are still unclear, and future work will have to investigate further.

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
SEP 07, 2020
Genetics & Genomics
Lactose Tolerance Quickly Moved Through Europe
SEP 07, 2020
Lactose Tolerance Quickly Moved Through Europe
Researchers have found evidence that humans in Europe gained the ability to metabolize the lactose, the sugar in milk, a ...
SEP 18, 2020
Coronavirus
How Coronavirus Spread in the US and Europe
SEP 18, 2020
How Coronavirus Spread in the US and Europe
Researchers are beginning to examine how the world's response to the pandemic virus SARS-CoV-2 went wrong, and right ...
SEP 20, 2020
Genetics & Genomics
Errors in the Nuclear Envelope Linked to Microcephaly
SEP 20, 2020
Errors in the Nuclear Envelope Linked to Microcephaly
Researchers have found that errors in a gene called LMNB1, which produces the lamin B1 protein, have devastating effects ...
SEP 30, 2020
Genetics & Genomics
Not All Vikings Were Scandinavian, New Genetic Research Shows
SEP 30, 2020
Not All Vikings Were Scandinavian, New Genetic Research Shows
Genetic research has upended what we thought was true of Vikings. These seafaring invaders left archeological sites thro ...
OCT 20, 2020
Genetics & Genomics
The Gene Behind the Glow of the Sea Pickle is ID'ed
OCT 20, 2020
The Gene Behind the Glow of the Sea Pickle is ID'ed
In this photo by OceanX, researchers off the coast of Brazil collected Pyrosoma atlanticum specimens with a special robo ...
NOV 16, 2020
Genetics & Genomics
Hidden Genes in the SARS-CoV-2 Genome
NOV 16, 2020
Hidden Genes in the SARS-CoV-2 Genome
It's essential for organisms to use their genomes to make proteins, and the processes of transcription and translation a ...
Loading Comments...