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
BS
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, 2022
Cell & Molecular Biology
Sequencing Living Cells, Individually, Without Killing Them
SEP 07, 2022
Sequencing Living Cells, Individually, Without Killing Them
When genes in a cell are active, they are transcribed into messenger RNA (mRNA) molecules. So researchers can take a sna ...
SEP 12, 2022
Cancer
Novel Method to Detect Cancer with a Blood Screen Demonstrates Feasibility
SEP 12, 2022
Novel Method to Detect Cancer with a Blood Screen Demonstrates Feasibility
Early detection of cancer benefits patients with almost all cancer types.  Late-stage tumors remain more difficult ...
OCT 04, 2022
Genetics & Genomics
New Insights Into How Breaks in 'Junk' DNA are Repaired
OCT 04, 2022
New Insights Into How Breaks in 'Junk' DNA are Repaired
For many years researchers focused attention on protein-coding genes, and while they are very important, they only accou ...
OCT 17, 2022
Genetics & Genomics
Genetic Markers Can Differentiate Between ADHD & Autism
OCT 17, 2022
Genetic Markers Can Differentiate Between ADHD & Autism
The symptoms of attention deficit/hyperactivity disorder (ADHD) and autism have many things in common; they are both com ...
NOV 10, 2022
Neuroscience
HUSH - A Complex That Silences Genes & Helps Control Brain Architecture
NOV 10, 2022
HUSH - A Complex That Silences Genes & Helps Control Brain Architecture
The HUSH (human silencing hub) protein complex is known to silence genes, and researchers have thought that it could be ...
NOV 16, 2022
Coronavirus
Divergent SARS-CoV-2 Variant Reveals Evidence of Deer-to-Human Transmission
NOV 16, 2022
Divergent SARS-CoV-2 Variant Reveals Evidence of Deer-to-Human Transmission
After only a few months of the COVID-19 pandemic, researchers had identified the virus that causes the disease, SARS-CoV ...
Loading Comments...