SEP 08, 2019 1:11 PM PDT

The Microbiome is Affected by the Genome of Its Host

WRITTEN BY: Carmen Leitch

Our health is significantly impacted by the dynamic microbial communities we carry in and on our bodies, especially the one in our gastrointestinal tract - the gut microbiome. Many factors influence the composition of that microbiome, including our environment, the foods we eat and the medicines we ingest. Our genes also impact those microbes, which have genes of their own. It’s a complex system, to be sure, but now scientists are learning more about how small variations in gene sequences can affect the gut microbiome.

This image shows a histologic section of intestinal tissue isolated from healthy mice stained to visualize intestinal epithelial cells/ Credit: Lance Peterson, Theresa Alenghat, and David Artis. Perelman School of Medicine, University of Pennsylvania.

Reporting in PLOS Genetics, researchers led by Federico Rey of the University of Wisconsin - Madison have used a mouse model to investigate how small changes in various genes related to bile acids influence the mouse microbiome. They found genetic variants that alter bile acid levels, and that can influence the size of a specific microbial population in the gut.

Bile acids sit at the intersection of gut bacteria and the genome of an individual. The host’s body uses the instructions in the genome to generate bile acids, which help break down the food we ingest so that nutrients can be absorbed by the small intestine. The bile acids can encourage the growth of some microbes and discourage the expansion of others in the intestine. Bacteria there can also metabolize and modify the bile acids, producing secondary bile acids in the process, which also affect the host’s digestion.

In this work, the scientists assessed 400 mice with diverse genomes, to identify the genetic variations that had an impact on the gut microbiome. They hypothesized that bile acid variants are related to differences in the microbiome. They zeroed in on a gene that encodes for a protein that absorbs bile acids in the last section of the small intestine so the acids can be sent back to the liver; the protein is called the ileal bile acid transporter. Small changes in this gene can affect the levels of a bacterial group called Turicibacter, and influence how much of a bile acid metabolite is present in the blood.

"We are interested in identifying the microbial functions that are under host genetic control," said study author Federico Rey, "and future studies will integrate additional metabolomic, metagenomic and transcriptional data derived from the host intestine."

This research can help show how to identify relationships between the microbes we carry in our guts and specific aspects of our physiology. Much more work will be needed to fully understand how host genetics, the microbiome, the environment, and host health are all connected, but studies like this one are a start.

In the research talk in the video above, Rey discusses metabolites made by the microbiome.


Sources: AAAS/Eurekalert! via PLOS, PLOS Genetics

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
MAY 26, 2021
Genetics & Genomics
Connecting Bacterial Genes to Human Disease
MAY 26, 2021
Connecting Bacterial Genes to Human Disease
This kind of research gets us closer to using fecal samples to get a snapshot of the microbiome, and make disease risk p ...
JUN 04, 2021
Cell & Molecular Biology
Even When They're Outside the Brain, Infections Worsen Alzheimer's
JUN 04, 2021
Even When They're Outside the Brain, Infections Worsen Alzheimer's
It's thought that inflammation is closely connected to cognitive decline, and neuroinflammation plays a role role in the ...
JUN 24, 2021
Microbiology
New Species of Fungi Found Growing From Ancient Ant
JUN 24, 2021
New Species of Fungi Found Growing From Ancient Ant
Scientists have discovered an unusual specimen of fungus that is making a carpenter ant its home; this discovery is the ...
JUL 11, 2021
Microbiology
COVID-19 Delta Variant Seems to Grow Faster & Be More Contagious
JUL 11, 2021
COVID-19 Delta Variant Seems to Grow Faster & Be More Contagious
In October 2020, what's now called the Delta variant of SARS-CoV-2 was first detected. It's now the most prevalent strai ...
JUL 13, 2021
Immunology
A Moment of COVID, A Lifetime of Immune Protection?
JUL 13, 2021
A Moment of COVID, A Lifetime of Immune Protection?
Does getting vaccinated, or having recovered from COVID, provide life-long protection against the coronavirus? Most like ...
JUL 18, 2021
Microbiology
Alarming Rise in Antibiotic Resistance Among Bangladeshi Kids with Pneumonia
JUL 18, 2021
Alarming Rise in Antibiotic Resistance Among Bangladeshi Kids with Pneumonia
Antibiotic resistance is a growing threat to public health, and experts have been warning about it for so long, they've ...
Loading Comments...