Finding the genes that help kingfishers dive without hurting their brains

Peer-Reviewed Publication

FIELD MUSEUM

 

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A DIVING KINGFISHER.

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CREDIT: RICHARD TOWELL

If you’ve ever belly-flopped into a pool, then you know: water can be surprisingly hard if you hit it at the wrong angle. But many species of kingfishers dive headfirst into water to catch their fishy prey. In a new scientific study in the journal Communications Biology, researchers compared the DNA of 30 different kingfisher species to zero in on the genes that might help explain the birds’ diet and ability to dive without sustaining brain damage.

The type of diving that kingfishers do-- what researchers call “plunge-diving”-- is an aeronautic feat. “It’s a high-speed dive from air to water, and it’s done by very few bird species,” says Chad Eliason, a research scientist at the Field Museum in Chicago and the study’s first author. But it’s a behavior that’s potentially risky. 

“For kingfishers to dive headfirst the way they do, they must have evolved other traits to keep them from hurting their brains,” says Shannon Hackett, associate curator of birds at the Field Museum and the study’s senior author. 

Not all kingfishers actually fish-- many species of these birds eat land-dwelling prey like insects, lizards, and even other kingfishers. Previously, co-authors Jenna McCollough and Michael Andersen, researchers from the University of New Mexico, led the team in using DNA to show that the groups of kingfishers that eat fish aren’t each others’ closest relatives within the kingfisher family tree. That means that kingfishers evolved their fishy diets-- and the diving abilities to procure them-- a number of separate times, rather than all evolving from one common fish-eating ancestor.

“The fact that there are so many transitions to diving is what makes this group both fascinating and powerful, from a scientific research perspective,” says Hackett. “If a trait evolves a multitude of different times independently, that means you have power to find an overarching explanation for why that is.”

For this study, the researchers-- including co-authors Lauren Mellenthin currently at Yale University, but who was an undergraduate intern at Field Museum at the time this research was conducted, Taylor Hains at the University of Chicago and Field Museum, Stacy Pirro at Iridian Genomes, and Michael Anderson and Jenna McCullough at the University of New Mexico-- examined the DNA of 30 species of kingfishers, both fish-eating and not. 

“To get all the kingfisher DNA, we used specimens in the Field Museum’s collections,” says Eliason, who works in the Field’s Grainger Bioinformatics Center and Negaunee Integrative Research Center. “When our scientists do fieldwork, they take tissue samples from the bird specimens they collect, like pieces of muscle or liver. Those tissue samples are stored at the Field Museum, frozen in liquid nitrogen, to preserve the DNA.”

In the Field’s Pritzker DNA Laboratory, the researchers began the process of  sequencing full genomes for each of the species, generating the entire genetic code of each bird. From there, they used software to compare the billions of base pairs making up these genomes to look for genetic variations that the diving kingfishers have in common.

The scientists found that the fish-eating birds had several modified genes associated with diet and brain structure. For instance, they found mutations in the birds’ AGT gene, which has been associated with dietary flexibility in other species, and the MAPT gene, which codes for tau proteins that relate to feeding behavior.

Tau proteins help stabilize tiny structures inside the brain, but the accumulation of too many tau proteins can be a bad thing. In humans, traumatic brain injuries and Alzheimer’s disease are associated with a buildup of tau. “I learned a lot about tau protein when I was the concussion manager of my son’s hockey team,” says Hackett. “I started to wonder, why don’t kingfishers die because their brains turn to mush? There’s gotta be something they're doing that protects them from the negative influences of repeatedly landing on their heads on the water’s surface.”

Hackett suspects that tau proteins may be something of a double-edged sword. “The same genes that keep your neurons in your brain in all nice and ordered are the things that fail when you get repeated concussions if you're a football player or if you get Alzheimer's,” she says. “My guess is there’s some sort of strong selective pressure on those proteins to protect the birds’ brains in some way.” 

Now that these correlated genomic variations  have been identified, says Hackett, “the next question is, what do the mutations in these birds’ genes do to the proteins that are being produced? What shape changes are there? What is going on to compensate in a brain for the concussive forces?”

“Now, we know which of the underlying genes are shifting that help create the differences that we see across the kingfisher family,” says Eliason. “But now that we know which genes to look at, it created more mysteries. That’s how science works.”

In addition to a better understanding of kingfisher genetics and potential implications for understanding brain injuries, Hackett says that this study is important because it highlights the value of museum collections. 

“One of the specimens we got DNA from in this study is thirty years old. At the time it was collected, we couldn’t do anywhere near the kind of analyses we can do today-- we couldn’t even do some of this stuff five years ago,” says Hackett. “It traces back to the ability of individual specimens to tell new stories through time. And who knows what we’ll be able to learn from these specimens in the future? That’s why I love museum collections.”

A kingfisher with a fish.

CREDIT

Richard Towell

Kingfisher study skins in the collections of the Field Museum.

CREDIT

Kate Golembiewski

Tissue samples in cryogenic storage, kept cold with liquid nitrogren, at the Field Museum.

CREDIT

John Weinstein, Field Museum

JOURNAL

Communications Biology

ARTICLE TITLE

Genomic signatures of convergent shifts to plunge-diving behavior in birds

ARTICLE PUBLICATION DATE

24-Oct-2023

 

How eggs of the Zika-carrying mosquito survive desiccation

Identification of metabolic pathway points to new control opportunities

Peer-Reviewed Publication

PLOS

 

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A MALE AND A FEMALE AEDES MOSQUITO, TAKEN IN THE RESEARCHERS’ LAB.

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CREDIT: ANJANA PRASAD (CC-BY 4.0, HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)

Eggs of the mosquito that carries Zika virus can tolerate extended desiccation by altering their metabolism, according to a new study publishing October 24th in the open access journal PLOS Biology by Anjana Prasad, Sunil Laxman, and colleagues at the Institute for Stem Cell Science and Regenerative Medicine in Bengaluru, India and the Indian Institute of Technology in Mandi, India. The finding offers potential new ways to control the spread of this mosquito.

Cells are made mostly of water, and desiccation is a potentially fatal event for any organism, since the structures of many proteins and other cellular molecules are dependent on adequate hydration. While many types of microbes have evolved mechanisms to survive drying out, only a few animals have. Among them is the mosquito Aedes aegypti, the carrier of a variety of viral diseases, including, Zika, dengue, yellow fever, and Chikungunya. Originally found in North Africa, Ae. aegypti has expanded globally, and is now a threat in warm, moist regions throughout the world.

Aedes eggs require from 48 to 72 hours to hatch into larvae, and the authors first showed that eggs must be at least 15 hours old to survive desiccation; eggs that were dried out before this stage failed to hatch when rehydrated. They then compared the proteomes of viable eggs that had and had not been desiccated, and found multiple major changes in metabolic pathways within the desiccated eggs. These included increases in the levels of those enzymes in the tricarboxylic acid (Krebs) cycle that promote lipid metabolism, and a decrease in enzymes of glycolysis and ATP-producing parts of the TCA cycle, which together shunted cellular metabolism toward the production and use of fatty acids. Overall, the level of metabolism was reduced, while the levels of the amino acids arginine and glutamine were increased. In addition, enzymes that reduce the damaging effects of oxidative stress, a known consequence of dehydration, were also increased.

When linked together, arginine molecules form polyamines, which are known to help protect nucleic acids, proteins, and membranes from a variety of insults. Here, the authors showed that the eggs accumulate polyamines, suggesting that they may be a key aspect of desiccation tolerance. To test this, they fed egg-laying female mosquitoes an inhibitor of polyamine synthesis. The eggs that they laid were significantly less able to survive desiccation than eggs from untreated females. A second inhibitor, this one of fatty acid metabolism, also reduced egg viability after desiccation. Finally, they showed that this fatty acid inhibitor reduced polyamine synthesis, indicating that one role of the increase in fatty acid breakdown is to supply the energy needed for production of protective polyamines.

“Given the importance of Ae. aegypti as a primary vector for numerous viral diseases that affect nearly half the world’s population,” Laxman said, “as well as the rapid geographical expansion of this mosquito vector, these results provide a foundation for reducing Aedes egg survival and global spread. Additionally, some of the specific inhibitors described here that reduce desiccation resistance in Ae. aegypti eggs, as well as new ones affecting other steps in the egg desiccation tolerance pathway, may prove useful as vector-control agents.”

Laxman adds, “Aedes mosquito eggs can indefinitely survive after drying up completely, and hatch into viable larvae. The embryos rewire their metabolism upon drying, to protect themselves through desiccation, and revive after water becomes available again.”

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In your coverage, please use this URL to provide access to the freely available paper in PLOS Biology: http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002342

Citation: Prasad A, Sreedharan S, Bakthavachalu B, Laxman S (2023) Eggs of the mosquito Aedes aegypti survive desiccation by rewiring their polyamine and lipid metabolism. PLoS Biol 21(10): e3002342. https://doi.org/10.1371/journal.pbio.3002342

Author Countries: India

Funding: No specific funding was obtained for this study. DST-INSPIRE (IF190149 to SS) and DBT/Wellcome Trust India Alliance (IA/I/19/1/504286 to BB) supported individual fellowships. These funders had no role in study design, data collection and analysis, support for experiments, decision to publish, or preparation of the manuscript. Intramural support was provided by the Tata Institute for Genetics and Society (to BB), and DBT-inStem (to SL).

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JOURNAL

PLoS Biology

DOI

10.1371/journal.pbio.3002342 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

 

How mosquito-controlling bacteria might also enhance insect fertility

Biological mechanisms found in fruit flies could inform efforts against disease-spreading mosquitos

Peer-Reviewed Publication

PLOS

 

IMAGE: 

A MEI-P26 MUTANT DROSOPHILA MELANOGASTER OVARIOLE INFECTED WITH WMEL BACTERIAL SYMBIONTS. DNA IS STAINED IN RED, ANTI-VASA PROTEIN IS STAINED BLUE, AND ANTI-HU-LI TAI SHAO RING CANAL PROTEIN IS STAINED CYAN.

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CREDIT: SHELBI RUSSELL (CC-BY 4.0, HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)

A new study reveals biological mechanisms by which a specific strain of bacteria in the Wolbachia genus might enhance the fertility of the insects it infects—with potentially important implications for mosquito-control strategies. Shelbi Russell of the University of California Santa Cruz, US, and colleagues report these findings in the open access journal PLOS Biology on October 24th.

Different strains of Wolbachia bacteria naturally infect a number of different animals worldwide, such as mosquitos, butterflies, and fruit flies. Wolbachia can manipulate the fertility of their hosts through a specific biological mechanism that aids the spread of Wolbachia within host populations. In recent years, people have harnessed that mechanism in strategies to deliberately infect mosquitos with a specific Wolbachia strain, reducing targeted mosquito populations and thereby potentially reducing the spread of human viruses carried by mosquitos, such as dengue or Zika.

Research in fruit flies suggests that that same strain, which is native to fruit flies, may also enhance insect fertility, with potentially important implications for mosquito control. Evidence suggests that biological processes involving the fruit-fly protein meiotic-P26 (“mei-P26"), which is essential for fruit-fly reproduction, may underlie this enhanced fertility. However, these processes have remained unclear.

To investigate, Russell and colleagues bred fruit flies with various defects affecting mei-P26—resulting in reduced fruit-fly fertility—and examined what happened when they then infected the flies with the fruit-fly-native Wolbachia strain.

They found that Wolbachia infection restored fertility in fruit flies with various mei-P26 defects, enabling them to produce more offspring than uninfected flies. Further experiments revealed how Wolbachia may restore fertility by mitigating certain perturbing effects of mei-P26 defects on specific genes and proteins, thereby resolving problems with the stem cells that produce fruit fly eggs and sperm.

In additional experiments, Wolbachia infection also enhanced the fertility of fruit flies without mei-P26 defects, resulting in higher egg lay and hatch rates.

These findings help to resolve the mystery of how this particular Wolbachia strain enhances fruit-fly fertility. Further research will be needed to better understand these effects and their potential implications for strategies that employ this strain to control mosquito populations.

Russell adds, “Wolbachia endosymbionts exist at high infection frequencies in many host populations, despite exhibiting weak gene drive systems and unobserved impacts on host fitness. Here, we show that the wMel strain of Wolbachia is able to rescue and reinforce host fertility, demonstrating their capacity to function as a beneficial symbiont.”

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In your coverage, please use this URL to provide access to the freely available paper in PLOS Biology: http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002335

Citation: Russell SL, Castillo JR, Sullivan WT (2023) Wolbachia endosymbionts manipulate the self-renewal and differentiation of germline stem cells to reinforce fertility of their fruit fly host. PLoS Biol 21(10): e3002335. https://doi.org/10.1371/journal.pbio.3002335

Author Countries: United States

Funding: This work was supported by the UC Santa Cruz Chancellor’s Postdoctoral Fellowship and the NIH (R00GM135583 to SLR; R35GM139595 to WTS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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JOURNAL

PLoS Biology

DOI

10.1371/journal.pbio.3002335 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

COI STATEMENT

Competing interests: The authors have declared that no competing interests exist.

Bacteria can enhance host insect’s fertility with implications for disease control

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SANTA CRUZ

 

IMAGE: 

A MEI-P26 MUTANT DROSOPHILA MELANOGASTER OVARIOLE INFECTED WITH WMEL BACTERIAL SYMBIONTS. DNA IS STAINED IN RED, ANTI-VASA PROTEIN IS STAINED BLUE, AND ANTI-HU-LI TAI SHAO RING CANAL PROTEIN IS STAINED CYAN.

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CREDIT: SHELBI RUSSELL, UC SANTA CRUZ.

Mosquitoes and other insects can carry human diseases such as dengue and Zika virus, but when those insects are infected with certain strains of the bacteria Wolbachia, this bacteria reduces levels of disease in their hosts. Humans currently take advantage of this to control harmful virus populations across the world.

New research led at UC Santa Cruz reveals how the bacteria strain Wolbachia pipientis also enhances the fertility of the insects it infects, an insight that could help scientists increase the populations of mosquitoes that do not carry human disease.

“With insect population replacement approaches, they keep all the mosquitos and just add Wolbachia so that fewer viruses are carried in those mosquitoes and transmitted to humans when they bite them — and it's working really, really well,” said Shelbi Russell, an assistant professor of biomolecular engineering at UCSC who led this research. “If there is some fertility benefit of Wolbachia that could evolve over time, then we could use that to select for higher rates of mosquitos that suppress our viral transmission.”

These results were detailed in a new paper led by Russell, published today in the journal PLOS Biology. UCSC Professor of Molecular, Cell, and Developmental Biology William Sullivan is the paper’s senior author.

Humans and Wolbachia 

Different strains of Wolbachia bacteria naturally infect a number of different animals worldwide, such as mosquitos, butterflies, and fruit flies. Once they infect an insect, the bacteria are able to manipulate the reproduction and development of their host to increase their own population. Humans take advantage of this to control the population size of insects that carry diseases that threaten us. 

Wolbachia have developed a mechanism to poison the sperm of infected males so that if the male mates with an uninfected female, most of the potential offspring die at the very first cell division, and the rest are lost soon after. Humans have taken advantage of this to kill off insect populations. 

However, research shows that later down the line once they have killed off as many uninfected hosts as possible, Wolbachia switch their evolutionary strategy to increase population levels of infected hosts. Understanding how this happens is important for avoiding unexpected consequences of human efforts to control insect populations. 

“We need to understand all of these factors and their evolutionary potential if we're going to be releasing bacteria into new ecosystems,” Russell said. “They're evolving in real time, so we need to understand where these trajectories are going.”

Beyond disease prevention, controlling insect populations and range via bacteria could be an effective mechanism for crop security in the face of the changing climate.  

Understanding increased fertility

The new results show that Wolbachia pipientis, which is native to fruit flies, has evolved to increase the fertility, and therefore the population size, of its fruit fly host. Previous research has found that the Wolbachia pipientis achieves this by manipulating a protein in fruit flies called Meiotic-P26 that affects fertility, but how exactly this happens was unclear.

To investigate, Russell and her colleagues bred fruit flies with various defects affecting Mei-P26, which caused them to have reduced fertility. These defects occasionally occur naturally in the wild, but are hard to track in that setting. The researchers then examined what happened when they infected the flies with Wolbachia pipientis.

They found that Wolbachia infection restored the fruit fly’s fertility, enabling them to produce even more offspring than uninfected flies. The researchers found that Wolbachia can essentially undo gene defects in their host that would otherwise cause the population to go extinct. The Wolbachia rescue their host population through several strategies, including restoring fruit fly stem cells and ensuring that egg cells properly develop.

In further experiments, the researchers also found that, beyond rescuing fruit flies with defects, the Wolbachia pipientis infection also enhances the health and fertility of fruit flies without defects, resulting in higher egg lay and hatch rates for those insects. 

Wolbachia in the lab

Russell focuses on Wolbachia because it and its fruit fly hosts are relatively easy to keep alive and reproduce in the lab. Oftentimes when scientists study bacteria, their efforts are hindered because either the host, the bacteria, or both are difficult to keep alive in the lab setting — even research into common bacteria important to humans such as Chlamydia are slowed by this problem. Wolbachia and their fruit fly hosts offer a rare opportunity to understand how bacteria can change the DNA and biological processes of their host.

“Through studying this system, I can learn a lot about how these weird bacteria work and how they integrate with host biology,” Russell said. “Bacteria are able to hop into these eukaryotes and leverage some of those mechanisms that their ancestors didn't even contain the genes for. It's a really fascinating thing in general, and it's cool that we can leverage this for biological control applications.”

Russell and her lab will continue to hone in on the specific changes that occur in the genomes and gene expression of host species, and look at the fertility benefits that Wolbachia may bring to their hosts in other insect populations.

Russell led this research primarily during her time as a postdoctoral scholar in Sullivan’s lab, where she was supported by the UC Santa Cruz Chancellor’s Postdoctoral Fellowship and funding from the National Institutes of Health. 

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JOURNAL

PLoS Biology

DOI

10.1371/journal.pbio.3002335 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Wolbachia endosymbionts manipulate the self-renewal and differentiation of germline stem cells to reinforce fertility of their fruit fly host

ARTICLE PUBLICATION DATE

24-Oct-2023

How to slow the spread of deadly ‘superbugs’

Harnessing new advances in genomic surveillance technology could help detect the rise of deadly ‘superbugs’.

Peer-Reviewed Publication

UNIVERSITY OF TECHNOLOGY SYDNEY

 

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BACTERIA IN A PETRI DISH

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CREDIT: UTS (GENERATED BY AI)

Harnessing new advances in genomic surveillance technology could help detect the rise of deadly ‘superbugs’ and slow their evolution and spread, improving global health outcomes, a new Australian study suggests.

Antimicrobial resistance occurs when bacteria, viruses, fungi and parasites change over time and no longer respond to the medicines and chemicals we use to kill them. These ‘superbugs’ make infections harder to treat and increase the risk of disease spread, severe illness and death.

Without significant intervention, global annual deaths involving antimicrobial resistance are estimated to reach 10 million by 2050, with low and middle-income countries bearing the highest burden. 

The new study, Genomic surveillance for antimicrobial resistance — a One Health perspective, published in Nature Reviews Genetics, highlights the need for a multifaceted ‘One Health’ approach to the surveillance of antimicrobial resistance in the environment.

The research was led by Distinguished Professor Steven Djordjevic from the Australian Institute for Microbiology and Infection at the University of Technology Sydney, together with researchers from the University of Melbourne and the University of South Australia. 

“Antimicrobial resistance is a complex and global threat requiring large-scale, co-ordinated and cross-disciplinary collaboration to tackle,” said Professor Djordjevic. 

“Understanding the evolution, emergence and spread of antimicrobial resistance within and between humans, animals, plants and natural environments is critical in mitigating the colossal impacts associated with this phenomenon.”

The use of genomic tracing during the Covid-19 pandemic has provided insight into the potential of genomic technologies to monitor the development and spread of antimicrobial genes and mutations.

“Antimicrobial resistance can occur when microorganisms acquire genetic information, either by mutation, recombination or transfer of antibiotic resistance genes from the bacterial gene pool,” said Professor Erica Donner from the University of South Australia.

“Genomic technologies, combined with AI and machine learning, are powerful platforms for determining resistance trends. They can identify instances where microbes and their genetic material move between different environments, evaluating the impact of intervention strategies.

“The evolution of antimicrobial resistance is a complex process that includes the overuse and misuse of antibiotics, metals and disinfectants in medicine and agriculture, and widely varying standards of water, sanitation and hygiene.”

The paper is a call to action for policymakers, highlighting the need to establish national genomic surveillance programs spanning human health, animal health, agriculture, food and environmental management sectors and to share data at both a national and international level.

“Utilising the technology of microbial genomics in the context of effective cross-sectoral data integration will enhance the understanding of antimicrobial resistance emergence and spread within and across these sectors and identify targeted interventions” said Professor Ben Howden from the University of Melbourne.

The researchers provide practical recommendations to implement genomics-enabled surveillance and mitigation strategies and underscore the need for equitable solutions that allow integration of partners from lower- and middle-income countries. 

The recommendations include:

• Establishing a national One Health antimicrobial resistance surveillance programme incorporating genomics
• Increase antimicrobial resistance awareness and education and foster collaboration
• Enhancing laboratory capacity in lower and middle-income countries
• Encouraging research and innovation
• Strengthening regulation and oversight in agriculture
• Improving antibiotic stewardship

“The evolutionary nature of antimicrobial resistance makes it a constantly changing and evolving threat. There is no easy solution, but ongoing genomic surveillance can help us better understand and mitigate this global health challenge,” said Professor Djordjevic.

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JOURNAL

Nature Reviews Genetics

DOI

10.1038/s41576-023-00649-y 

METHOD OF RESEARCH

Systematic review

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Genomic surveillance for antimicrobial resistance — a One Health perspective

 

Proven for the first time: The microbiome of fruit and vegetables positively influences diversity in the gut

In a meta-study, a research team from the Institute of Environmental Biotechnology at Graz University of Technology has provided evidence that the consumption of fruit and vegetables contributes positively to bacterial diversity in the human gut.

Peer-Reviewed Publication

GRAZ UNIVERSITY OF TECHNOLOGY

 

IMAGE: 

GABRIELE BERG AND WISNU ADI WICAKSONO FROM THE INSTITUTE OF ENVIRONMENTAL BIOTECHNOLOGY AT TU GRAZ

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CREDIT: WICAKSONO - TU GRAZ

Bacterial diversity in the gut plays an important role in human health. The crucial question, however, is where are the sources of this diversity? It is known that an important part of the maternal microbiome is transferred to the baby at birth, and the same happens during the breastfeeding period via breast milk. Further sources were yet to be discovered. However, a team led by Wisnu Adi Wicaksono and Gabriele Berg from the Institute of Environmental Biotechnology at Graz University of Technology (TU Graz) has now succeeded in proving that plant microorganisms from fruit and vegetables contribute to the human microbiome. They report this in a study published in the journal Gut Microbes.

You are what you eat

The authors were able to demonstrate that the frequency of fruit and vegetable consumption and the variety of plants consumed influences the amount of fruit- and vegetable-associated bacteria in the human gut. Early childhood in particular represents a window of opportunity for colonisation with plant-associated bacteria. It was also demonstrated that the microorganisms of plant origin have probiotic and health-promoting properties.

A microbiome is the totality of all microorganisms that colonise a macroorganism (human, animal, plant) or a part of it, for example the intestine or a fruit. While the individual microbiomes are becoming better understood, little is known about their connections. “The proof that microorganisms from fruits and vegetables can colonise the human gut has now been established for the first time,” explains first author Wisnu Adi Wicaksono. This suggests that the consumption of fruit and vegetables, especially in infancy, has a positive influence on the development of the immune system in the first three or so years of life, as the intestinal microbiome develops during this time. But even after that, a good diversity of gut bacteria is beneficial for health and resilience. “It simply influences everything. Diversity influences the resilience of the whole organism; higher diversity conveys more resilience,” says Institute head Gabriele Berg.

Several billion sequences

In order to be able to determine that the consumption of fruits and vegetables and their microbiomes actually leads to changes in the intestinal microbiome, the team first created a catalogue of microbiome data from fruits and vegetables which enabled them to assign their bacteria. They compared these with publicly available data from two studies on intestinal flora. The TEDDY project looked at the development of babies in a long-term study and the American Gut Project studied the intestinal microbiome of adults – both projects also collected data on the food intake of the test persons. In total, the researchers had metagenome data from around 2500 stool samples at their disposal, each of which contained between one and ten million sequences – several billion sequences were thus evaluated. Using this extensive data set, the presence of fruit and vegetable microflora in the gut could be demonstrated. This evidence is a crucial building block in proving the WHO’s One Health concept, which closely links human, animal and environmental health.

Follow-up study on three continents

To further explore this connection, together with international colleagues and within the EU-funded HEDIMED project (www.hedimed.eu) Gabriele Berg at the Institute of Environmental Biotechnology is already working on an intervention study in which people on three continents eat exactly the same things for a certain period of time, following which their excretions are analysed. But even beyond that, Gabriele Berg sees many areas that could be influenced on the basis of the study’s findings. This starts with food production, as soil, fertiliser and pesticides affect the plant microbiome. “Fresh fruit and vegetables will always have the best microbiome; agriculture or processing companies already have a major influence here. And the storage and processing of food must also be critically reconsidered,” explains Berg. Depending on the findings of the planned study, there could also be exciting applications for individuals. “Every fruit and vegetable has a unique microbiome. So maybe at some point a personalised diet can be put together based on that.”

This research is anchored in the Field of Expertise "Human & Biotechnology", one of five strategic foci of TU Graz.

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JOURNAL

Gut Microbes

DOI

10.1080/19490976.2023.2258565 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The edible plant microbiome: evidence for the occurrence of fruit and vegetable bacteria in the human gut