Nav: Home

Aging and nutrients competition determine changes in microbiota

March 11, 2020

Driven by the discovery of mechanisms associated with the microbiota (the set of microbes that make up the intestinal flora) and its impact on health, the two scientific articles now published are the result of work previously developed at IGC and which involves three Research Groups. In 2014, when researchers first realized that the bacterium E. coli, when introduced into the host, developed genetic mutations with a speed and frequency never before anticipated, new questions arose: What is the influence of the other species of bacteria in the intestine in this process? What influence does host aging have on the process? What impact does inflammation have on the evolution of the microbiota? What genetic mutations occur and how do they happen?

Using the mouse as an animal model (host) and the bacterium E. coli, a well-studied colonizer of the human intestine that is susceptible to mutations in the intestinal tract, the research groups have unveiled two new mechanisms in the microbiota.

The research group led by Isabel Gordo is interested in understanding how bacteria evolve. Knowing that old age leads to changes in the composition of gut bacteria, the study now published E. coli evolved in both communities.

Assuming that old age is associated with a progressive deterioration of the host functions, the surprising fact that resulted from this work shows that E. coli evolves in the elderly to cope with the stressful environment, becoming potentially pathogenic and potentially increasing the risk of disease.

The inflammation associated with the old age of the host gives an added stress factor to the bacterium in the gut, causing it to evolve into a version potentially more dangerous to the health of the host.

For Isabel Gordo, leader of the research group, "it was fascinating to observe that in just one month of colonization of the old mice, the evolution of E. coli revealed its versatility in acquiring mutations capable of adapting to the pressure imposed by the increased inflammation of the intestine".

The discoveries now made will allow the start of a new investigation focused on the study of these mechanisms in people with inflammatory bowel disease. In Portugal alone, inflammatory bowel disease (such as Ulcerative Colitis and Crohn's Disease) affects about 7000 to 15000 people and impacts their quality of life.

Knowing that E. coli evolves in young and elderly people differently, since in the intestine of the elderly the type of colonizing species differs from the type that colonizes the youngest, the researchers wanted to understand how this bacterium acts when alone or when accompanied.

The research group led by Karina Xavier, responsible for studying the signaling features of bacteria, found that the metabolism of E. coli differs if it is alone or in the company of other bacteria

When introduced into the host alone, E. coli proved to be an excellent colonizer, gaining a lot of space in its environment and consuming amino acids. When it is introduced in the company of another bacteria from the microbiota, Blautia coccoides, the investigation revealed that the genetic changes of the bacterium happened faster and in a mora diversified way due to the interaction: there is competition for available nutrients and E. coli starts to consume other nutrients, only made available due to the presence of B. coccoides.

This work shows that the evolution of E. coli in the mouse gut is responding primarly to the interaction with other members of the microbiota. According to the leader of the research group, Karina Xavier, " our data demonstrates that the presence of a competing species in the host's intestine alters the metabolic environment of the gut, and the bacteria quickly adapt to the new metabolic environement by reshapping their metabolism ". When alone in the gut E. coli evolved to be more efficient in consuming aminoacids, as these were the most abundant nutrients in the intestines. In the presence of a member of the microbiota aminoacids become scarce and simple sugars released by the metabolism of the micobiota members become available and thus evolution favored selection for mutants that are better in consuming these compounds. In the future "we will study how the microbiota reacts and evolves in the presence of different host behaviors, such as the type of diet, and how this is reflected in health or pathogenicity."
-end-


Instituto Gulbenkian de Ciencia

Related Bacteria Articles:

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.
Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.
Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.
Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.
Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.
How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.
The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?
Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.
Bacteria uses viral weapon against other bacteria
Bacterial cells use both a virus -- traditionally thought to be an enemy -- and a prehistoric viral protein to kill other bacteria that competes with it for food according to an international team of researchers who believe this has potential implications for future infectious disease treatment.
Drug diversity in bacteria
Bacteria produce a cocktail of various bioactive natural products in order to survive in hostile environments with competing (micro)organisms.
More Bacteria News and Bacteria Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.