Stress, via inflammation, is linked to metabolic syndrome

Study suggests stress management could reduce biological risk

Peer-Reviewed Publication

OHIO STATE UNIVERSITY

COLUMBUS, Ohio – Lifestyle and genetics, and a range of other factors within and outside our control, are known to contribute to development of metabolic syndrome, a cluster of conditions that add up to increased risk for serious health problems.

A new study has found that stress, through its propensity to drive up inflammation in the body, is also linked to metabolic syndrome – leading researchers to suggest that cheap and relatively easy stress-management techniques may be one way to help improve biological health outcomes.

“We were specifically examining people in midlife – a time that is critical to determine those who will experience accelerated aging. Stress is an important contributor to several negative health outcomes as we age,” said senior author Jasmeet Hayes, associate professor of psychology at The Ohio State University.

“There are many variables that influence metabolic syndrome, some we can’t modify, but others that we can. Everybody experiences stress,” Hayes said. “And stress management is one modifiable factor that’s cost-effective as well as something people can do in their daily lives without having to get medical professionals involved.”

The research was published recently in Brain, Behavior, & Immunity – Health.

Links between stress and biological health are established, but few previous studies had looked specifically at the involvement of inflammation in stress’s connection to metabolic syndrome.

People with metabolic syndrome are diagnosed with at least three of five factors that increase the risk for heart disease, diabetes and other health issues – excess belly fat, high blood pressure, low HDL (good) cholesterol, and high levels of fasting blood glucose and triglycerides, a type of fat in the blood. The condition is also referred to as insulin resistance syndrome.

Using data from a sample of 648 participants (average age 52) in a national survey titled Midlife in the United States, first author Savana Jurgens built a statistical model to gauge how inflammation may fit into the relationship between stress and metabolic syndrome. Information from respondents’ reported perceived stress, blood biomarkers for inflammation, and physical exam results indicating risk factors for metabolic syndrome was used for the analysis.

“There’s not much research that has looked at all three variables at one time,” said Jurgens, a psychology graduate student in Hayes’ lab. “There’s a lot of work that suggests stress is associated with inflammation, inflammation is associated with metabolic syndrome, and stress is associated with metabolic syndrome. But putting all those pieces together is rare.”

Inflammation composite scores were calculated using biomarkers that included the better-known IL-6 and C-reactive protein as well as E-selectin and ICAM-1, which help recruit white blood cells during inflammation, and fibrinogen, a protein essential to blood clot formation.

The statistical modeling showed that stress does indeed have a relationship with metabolic syndrome, and inflammation explained over half of that connection – 61.5%, to be exact.

“There is a small effect of perceived stress on metabolic syndrome, but inflammation explained a large proportion of that,” Jurgens said.

The results made sense – stress is just one of many factors that can launch health markers into a state of disarray. Other factors include a range of behaviors including inactivity, unhealthy eating habits, smoking and poor sleep, as well as low socioeconomic status, advanced age and being female.  

But considering that an estimated 1 in 3 American adults has metabolic syndrome, knowing how to lower risk or prevent it altogether is important, Hayes said. The findings also add to evidence that stress, and its connection to inflammation, can have a big impact on biological health in general.

“People think of stress as mental health, that it’s all psychological. It is not. There are real physical effects to having chronic stress,” Hayes said. “It could be inflammation, it could be metabolic syndrome, or a number of things. This is another reminder of that.”

Future work will include a closer look at whether stress has a causal effect on metabolic syndrome and assessing stress management techniques that may be best for helping reduce inflammation.

This research was supported by the National Institute on Aging and Ohio State’s Discovery Themes Chronic Brain Injury Program, where Hayes is an investigator. Co-author Sarah Prieto of Ohio State also contributed to the study.

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JOURNAL

Brain Behavior & Immunity - Health

DOI

10.1016/j.bbih.2023.100696 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Inflammatory biomarkers link perceived stress with metabolic dysregulation

 

Kessler Foundation scientist awarded prestigious federal grant for novel, mixed-method study on Latinos with multiple sclerosis

Researcher Cristina A. F. Román, PhD, to examine barriers to healthcare, cardiovascular risk factors, and accelerated brain aging in minoritized group

Grant and Award Announcement

KESSLER FOUNDATION

 

IMAGE: 

CRISTINA A. F. ROMAN, PHD, RESEARCH SCIENTIST IN THE ROCCO ORTENZIO NEUROIMAGING CENTER AT KESSLER FOUNDATION, RECEIVED A FEDERAL GRANT FOR ONE OF THE FIRST MIXED-METHODS STUDIES TO EXAMINE BARRIERS TO HEALTHCARE, MEDICAL COMORBIDITIES, AND ACCELERATED BRAIN AGING IN LATINO PERSONS WITH MULTIPLE SCLEROSIS.

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CREDIT: N/A

East Hanover, NJ – January 12, 2024 – A research scientist at Kessler Foundation has been awarded a highly competitive Mentored Patient-Oriented Research Career Development Award (K23) from the National Institute on Minority Health and Health Disparities, a part of the National Institutes of Health (NIH).

This $704,054, five-year grant will support one of the first mixed-methods studies aimed at examining barriers to healthcare, cardiovascular risk factors, and accelerated brain aging in Latinos with multiple sclerosis (MS). The Principal Investigator and grant recipient, Cristina A. F. Román, PhD, is currently a research scientist in the Foundation’s Rocco Ortenzio Neuroimaging Center.

Though there is a paucity of research focusing on Latinos with MS, there is evidence that this group experiences more severe disease trajectories and worse functional outcomes than their non-Latino counterparts. “These disparities are believed to be strongly influenced by social determinants of health, particularly factors related to healthcare access,” explained Dr. Román, adding, “Timely intervention and consistent, ongoing medical care are crucial for improving MS prognosis, especially in historically minoritized groups that face greater health disparities.”

Studies show that Latinos  encounter greater obstacles in accessing equitable healthcare, which not only contributes to poorer MS outcomes, but also increases the risk of comorbid medical conditions such as cardiovascular risk factors. These risk factors disproportionately impact both individuals with MS and Latino populations residing in the United States and can contribute to neurodegeneration (e.g., advanced brain aging). “This means that Latinos with MS are at especially high risk for the compounding effects of barriers to healthcare, cardiovascular risk factors, and MS, yet the extent to which these factors interact to impact MS-related outcomes, especially brain aging, remains unknown,” noted Dr. Román.

“The findings from our work will have direct implications for early intervention strategies, focusing on improving healthcare access and quality. Additionally, our research will significantly contribute to filling a substantial gap in our understanding of how societal and systemic factors (i.e., social determinants of health) influence brain health and health disparities in neurological disorders,” she concluded.

Funding: National Center on Minority Health and Health Disparities (NIH) 1K23MDO19232-01A0.

About the National Institute on Minority Health and Health Disparities (NIMHD)
The National Institute on Minority Health and Health Disparities (NIMHD) is one of the 27 Institutes and Centers of the National Institutes of Health (NIH), the nation's premiere medical research agency. NIMHD's work touches the lives of millions of Americans burdened by disparities in health status and health care delivery, including racial and ethnic minority groups, rural populations, populations with low socioeconomic status, and other population groups. For more information, visit NIMHD.gov.

About Kessler Foundation
Kessler Foundation, a major nonprofit organization in the field of disability, is a global leader in rehabilitation research. Our scientists seek to improve cognition, mobility, and long-term outcomes, including employment, for adults and children with neurological and developmental disabilities of the brain and spinal cord including traumatic brain injury, spinal cord injury, stroke, multiple sclerosis, and autism. Kessler Foundation also leads the nation in funding innovative programs that expand opportunities for employment for people with disabilities. For more information, visit KesslerFoundation.org.

Press Contacts at Kessler Foundation:
Deborah Hauss, DHauss@kesslerfoundation.org
Carolann Murphy, CMurphy@KesslerFoundation.org

Stay Connected with Kessler Foundation
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Using chatbots to advance Spanish-speaking patient outreach

Grant and Award Announcement

HUNTSMAN CANCER INSTITUTE

 

IMAGE: 

Kim Kaphingst, ScD, DIRECTOR OF CANCER COMMUNICATION RESEARCH AT Huntsman Cancer Institute AND PROFESSOR OF COMMUNICATIONS AT THE University of Utah.

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CREDIT: HUNTSMAN CANCER INSTITUTE

In her latest study, Kim Kaphingst, ScD, director of cancer communication research at Huntsman Cancer Institute and professor of communications at the University of Utah, is using chatbots to reach Spanish-speaking patients and teach them about genetic testing. 

The chatbots, computer programs that simulate conversation, give patients the same information they would get in an appointment with a genetic counselor to learn about genetic testing. This is done by using texted prompts, allowing for more flexibility and accessibility since patients can use this tool anywhere. If a patient meets the criteria for genetic testing, they can be offered testing through the genetic counseling team. 

And now, Kaphingst and her team have received additional funding from the National Cancer Institute for this specific project. “Our initial trial allowed us to develop and test the chatbot,” says Kaphingst. “This funding allows our team to reach a new population.” 

Kaphingst’s background in genetics and health communication has motivated her to find new ways to reach and educate patients. Her team of researchers include Crystal Lumpkins, Whitney Espinel, CGC, Wendy Kohlmann, MS, Guilherme Del Fiol, MD, PhD, FACMI, as well as Pete Taber, MSCI, PhD, from Biomedical Informatics.  

“It is important for people to know about their risk of cancer,” says Kaphingst. “As a cancer center, our goal is to effectively communicate this information to the public. There are many things individuals can do to reduce their risk, like early screening or preventative surgery. Our goal is to empower patients, ensuring they have the information necessary to make informed decisions about their health.” 

The new phase of this research will focus on Spanish-speaking women. According to Kaphingst, Spanish-speaking women are less likely to receive genetic testing services when compared to English-speaking patients. This means that patients with hereditary cancer risks, like hereditary breast and ovarian cancer, are less likely to be identified, which can lead to poorer health outcomes. 

“Our previous work has shown that about 25% to 30% of people who are eligible for genetic testing receive it,” says Kaphingst. “It is so important to address some of the inequities we see in the area we serve. It is really an important issue: making sure that everybody can access the services they need.” 

Huntsman Cancer Institute is home to many resources, including a patient navigation program specifically tailored for people who speak Spanish.  

The study was supported by the National Institutes of Health/National Cancer Institute including P30 CA042014 and Huntsman Cancer Foundation. The chatbots were developed in a recently completed trial funded by the Inherited Cancer Syndrome Collaborative of the Beau Biden Cancer Moonshot Initiative. 

 

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About Huntsman Cancer Institute at the University of Utah 

Huntsman Cancer Institute at the University of Utah (the U) is the National Cancer Institute-designated Comprehensive Cancer Center for Utah, Idaho, Montana, Nevada, and Wyoming. With a legacy of innovative cancer research, groundbreaking discoveries, and world-class patient care, we are transforming the way cancer is understood, prevented, diagnosed, treated, and survived. Huntsman Cancer Institute focuses on delivering a cancer-free frontier to all communities in the area we serve. We have more than 300 open clinical trials and 250 research teams studying cancer at any given time. More genes for inherited cancers have been discovered at Huntsman Cancer Institute than at any other cancer center. Our scientists are world-renowned for understanding how cancer begins and using that knowledge to develop innovative approaches to treat each patient’s unique disease. Huntsman Cancer Institute was founded by Jon M. and Karen Huntsman. 

 

Study uncovers potential origins of life in ancient hot springs

Peer-Reviewed Publication

NEWCASTLE UNIVERSITY

Newcastle University research turns to ancient hot springs to explore the origins of life on Earth.

The research team, funded by the UK’s Natural Environmental Research Council, investigated how the emergence of the first living systems from inert geological materials happened on the Earth, more than 3.5 billion years ago. Scientists at Newcastle University found that by mixing hydrogen, bicarbonate, and iron-rich magnetite under conditions mimicking relatively mild hydrothermal vent results in the formation of a spectrum of organic molecules, most notably including fatty acids stretching up to 18 carbon atoms in length.

Published in the journal Communications Earth & Environment, their findings potentially reveal how some key molecules needed to produce life are made from inorganic chemicals, which is essential to understanding a key step in how life formed on the Earth billions of years ago. Their results may provide a plausible genesis of the organic molecules that form ancient cell membranes, that were perhaps selectively chosen by early biochemical processes on primordial Earth.

Fatty acids in the early stages of life

Fatty acids are long organic molecules that have regions that both attract and repel water that will automatically form cell-like compartments in water naturally and it is these types of molecules that could have made the first cell membranes. Yet, despite their importance, it was uncertain where these fatty acids came from in the early stages of life. One idea is that they might have formed in the hydrothermal vents where hot water, mixed with hydrogen-rich fluids coming from underwater vents mixed with seawater containing CO2.

The group replicated crucial aspects of the chemical environment found in early Earth's oceans and the mixing of the hot alkaline water from around certain types of hydrothermal vents in their laboratory. They found that when hot hydrogen-rich fluids were mixed with carbon dioxide-rich water in the presence of iron-based minerals that were present on the early Earth it created the types of molecules needed to form primitive cell membranes.

Lead author, Dr Graham Purvis, conducted the study at Newcastle University and is currently a Postdoctoral Research Associate at Durham University.

He said: “Central to life's inception are cellular compartments, crucial for isolating internal chemistry from the external environment. These compartments were instrumental in fostering life-sustaining reactions by concentrating chemicals and facilitating energy production, potentially serving as the cornerstone of life's earliest moments.

The results suggest that the convergence of hydrogen-rich fluids from alkaline hydrothermal vents with bicarbonate-rich waters on iron-based minerals could have precipitated the rudimentary membranes of early cells at the very beginning of life. This process might have engendered a diversity of membrane types, some potentially serving as life's cradle when life first started. Moreover, this transformative process might have contributed to the genesis of specific acids found in the elemental composition of meteorites.”

Principal Investigator Dr Jon Telling, Reader in Biogeochemistry, at School of Natural Environmental Sciences, added:

“We think that this research may provide the first step in how life originated on our planet. Research in our laboratory now continues on determining the second key step; how these organic molecules which are initially ‘stuck’ to the mineral surfaces can lift off to form spherical membrane-bounded cell-like compartments; the first potential ‘protocells’ that went on to form the first cellular life.”

Intriguingly, the researchers also suggest that membrane-creating reactions similar reactions, could still be happening in the oceans under the surfaces of icy moons in our solar system today. This raises the possibility of alternative life origins in these distant worlds.

Reference

Purvis, G., Šiller, L., Crosskey, A. et al. Generation of long-chain fatty acids by hydrogen-driven bicarbonate reduction in ancient alkaline hydrothermal vents. Commun Earth Environ 5, 30 (2024). https://doi.org/10.1038/s43247-023-01196-4

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JOURNAL

Communications Earth & Environment

DOI

10.1038/s43247-023-01196-4 

METHOD OF RESEARCH

Computational simulation/modeling

ARTICLE TITLE

Generation of long-chain fatty acids by hydrogen-driven bicarbonate reduction in ancient alkaline hydrothermal vents

 

Study quantifies how aquifer depletion threatens crop yields

Yield losses intensify when groundwater dwindles, data shows

Peer-Reviewed Publication

UNIVERSITY OF NEBRASKA-LINCOLN

 

IMAGE: 

A CENTER-PIVOT IRRIGATION SYSTEM WATERS A CORNFIELD NEAR ADAMS, NEBRASKA, ABOUT 45 MINUTES SOUTH OF LINCOLN. A NEW HUSKER-LED STUDY SHOWS HOW THE DEPLETION OF GROUNDWATER — THE SAME THAT MANY FARMERS RELY ON FOR IRRIGATION — CAN THREATEN FOOD PRODUCTION AMID DROUGHT AND DRIER CLIMES. DUE IN PART TO THE CHALLENGES OF EXTRACTING GROUNDWATER, AN AQUIFER’S DEPLETION CAN CURB CROP YIELDS EVEN WHEN IT APPEARS SATURATED ENOUGH TO CONTINUE MEETING THE DEMANDS OF IRRIGATION, THE STUDY FOUND.

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CREDIT: CRAIG CHANDLER, UNIVERSITY OF NEBRASKA–LINCOLN

Three decades of data have informed a new Nebraska-led study that shows how the depletion of groundwater — the same that many farmers rely on for irrigation — can threaten food production amid drought and drier climes.

The study found that, due in part to the challenges of extracting groundwater, an aquifer’s depletion can curb crop yields even when it appears saturated enough to continue meeting the demands of irrigation. Those agricultural losses escalate as an aquifer dwindles, the researchers reported, so that its depletion exerts a greater toll on corn and soybean yields when waning from, say, 100 feet thick to 50 than from 200 feet to 150.

That reality should encourage policymakers, resource managers and growers to reconsider the volume of crop-quenching groundwater they have at their disposal, the team said, especially in the face of fiercer, more frequent drought.

“As you draw down an aquifer to the point that it’s quite thin, very small changes in the aquifer thickness will then have progressively larger and larger impacts on your crop production and resilience,” said Nick Brozović, director of policy at the Daugherty Water for Food Global Institute. “And that’s a thing that we don’t predict well, because we tend to predict based on the past. So if we base what’s going to happen on our past experience, we’re always going to underpredict. We’re always going to be surprised by how bad things get.”

The team came to its conclusions after analyzing yields, weather and groundwater data from the High Plains Aquifer, which, as the largest in the United States, underlies portions of eight states — including nearly all of Nebraska. Some areas of the aquifer, especially those beneath Texas and Kansas but also the Cornhusker State, have diminished considerably over the past several decades, pumped for the sake of irrigating land that would otherwise stand little chance of sustaining crops.

“In terms of things that let you address food security under extreme conditions — in particular, drought and climate change — we really can’t do without irrigation,” said Brozović, professor of agricultural economics at the University of Nebraska–Lincoln. “If we want to feed the world with high-quality, nutritious food and a stable food supply, we need to irrigate.”

Brozović and Husker colleague Taro Mieno had already constructed plenty of models, and run plenty of simulations, on how the High Plains Aquifer responds to drought and dry conditions. But talking with farmers revealed that the models were not addressing their primary concern: well yield, or the amount of groundwater that growers can expect to continuously draw when trying to buffer their crops against drought.

“Everybody’s interested in how aquifer depletion affects the resiliency of irrigated agriculture in the region,” said Mieno, an associate professor of agricultural economics and lead author of the study, which was published in the journal Nature Water.

So the researchers consulted annual estimates of the High Plains Aquifer’s thickness, which date back to 1935, along with county-level yields of corn and soybean from 1985 through 2016. Meteorological data, meanwhile, allowed the team to calculate seasonal water deficits, or the difference between the water gained from precipitation and the amount that crops lost via evaporation and transpiration.

When the latter exceeds the former, farmers often turn to aquifers for help in making up the difference, the researchers knew. What they didn’t know: Under what conditions, and to what extent, would an aquifer’s depletion make pumping its water too difficult or expensive to undertake? And how much would the resulting decisions — to reduce the amount of irrigation per acre, to cease irrigating certain plots all together — influence corn and soybean yields?

Farmers fortunate enough to be growing corn and soybean above the most saturated swaths of the High Plains Aquifer — roughly 220 to 700 feet thick — continued to enjoy high irrigated yields even in times of extreme water deficits, the team found. By contrast, those depending on the least saturated areas — between 30 and 100 feet — saw their irrigated yields begin trending downward when water deficits reached just 400 millimeters, a common occurrence in Nebraska and other Midwestern states.

In years when the deficit approached or exceeded 700 millimeters, irrigated fields residing above the thickest groundwater yielded markedly more corn than those sitting above the thinnest. The results were starker during a 950-millimeter water deficit, which corresponds with extreme drought: Fields atop the least saturated stretches of aquifer yielded roughly 19.5 fewer bushels per acre.

“Because of the way that aquifers work, even if there’s a lot of water there, as they deplete, you actually lose the ability to meet those crop water needs during the driest periods, because well yield tends to decline as you deplete an aquifer,” Brozović said. “That has an economic consequence and a resilience consequence.”

The study captured another telling link between the water residing underground and that applied at the surface. When atop groundwater roughly 330 feet thick, farmers irrigated 89% of their acres dedicated to growing corn. Where the aquifer was a mere 30 feet thick? Just 70% of those acres received irrigation. That’s likely a result of lower well yield driving farmers to irrigate only some of their fields, Taro said, or even give up on irrigation.

To better understand how that reduced irrigation was contributing to agricultural losses amid dry conditions, the researchers then factored in yields from both irrigated and non-irrigated fields, the latter of which rely on precipitation alone. That analysis pegged yields as even more sensitive to even smaller water deficits, suggesting that the decline in irrigated land was compounding the losses endured on still-irrigated plots.

And it illustrated the runaway threat posed when an aquifer’s average thickness drops below certain thresholds. At a water deficit of 950 millimeters, reducing an aquifer’s thickness from roughly 330 to 230 feet was estimated to initiate an average loss of about 2.5 corn bushels per acre, what the authors called a “negligible difference.” The same absolute decrease, but from 230 to 130 feet, led to an estimated loss of 15 bushels per acre.

“As a consequence, your resilience to climate decreases rapidly,” Mieno said. “So when you’re operating on an aquifer that is very thick right now, you’re relatively safe. But you want to manage it in a way that you don’t go past that threshold, because from there, it’s all downhill.

“And the importance of aquifers is going to increase as climate change progresses in the future, for sure. As it gets hotter, you typically need more water. That means you need more irrigation, and you’re going to deplete the aquifer even faster, and things can get worse and worse.”

Nebraska is lucky, Brozović said, in that it sits above such a massive reservoir and has established a governance system designed to conserve it at a local scale. But most regulations focus on mandating how much and when groundwater gets pumped, not safeguarding the aquifer’s saturation level or the corresponding ability to extract water from it.

Brozović conceded that convincing policymakers to consider revising those parameters now, when much of the state still boasts sufficient groundwater, is “perhaps a tough sell.” He’s hopeful that the new study can at least help put that conversation on the table.

“Once you have a problem — once well yields are already declining and the aquifer’s really thin — even if you put in policies, you still get a lot of the (negative) impacts,” he said. “So the time to really put in meaningful policies is before things have gone off the cliff.

“First, you have to understand, you have to measure, you have to educate. You have to understand what you’re preserving, and why. The more you can provide the quantitative evidence for why it’s worth going to the trouble of doing all of this, and what’s at stake,” he said, “the easier that conversation is.”

Brozović and Mieno authored the Nature Water study with the University of Manchester’s Timothy Foster and the University of Minnesota’s Shunkei Kakimoto. The researchers received support in part from the U.S. Department of Agriculture.

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JOURNAL

Nature Water

 

When bees nourish their microbiota

Peer-Reviewed Publication

UNIVERSITY OF LAUSANNE

Two teams from UNIL and EPFL have succeeded in demonstrating that the insect synthesizes nutrients for native gut microbes. A study published in « Nature Microbiology ».

Bacteria have adapted to all terrestrial environments. Some have evolved to survive in the gut of animals, where they play an important role for their host; they provide energy by degrading indigestible food, they train and regulate the immune system, they protect against invasion by pathogenic bacteria, and they synthesize neuroactive molecules that regulate the behavior and cognition of their host.

These are great advantages for the host, but what advantages do the bacteria derive? Certainly, the host provides a comfortable home, but does the host also provide nutrients to native bacteria that enable them to colonize?

It is a difficult question that is possible to answer with the aide of … bees. Professor Philipp Engel in UNIL's Department of Fundamental Microbiology (DMF) in Dorigny has set his sights on the western honey bee (Apis mellifera). They are a relatively simple system to study compared to humans and their gut microbiota. Best known for the delicious honey they produce, this insect is also an excellent experimental model for gut microbiota research: it has acquired a remarkably simple and stable microbiota, composed of only around twenty bacterial species. In the laboratory of the Engel group, bees are raised without gut bacteria, and then fed specific species that will colonize the gut. 

Full board for the bacteria

Bees love to gorge on nutrient rich pollen and honey, but they can also survive for long periods on a diet of only sugar water.  But what happens to the gut bacteria? A study published on January 15, 2024 in Nature Microbiology by the Lausanne scientists reveals new insights: Dr. Andrew Quinn and PhD candidate Yassine El Chazli began by looking for evidence that the bacteria share nutrients with one another when bees receive nothing more than sugar water. Remember that intestinal bacteria are known to consume dietary nutrients as well as waste products from other microorganisms.

However, their first results left them perplexed: One specific bacterium in the gut, Snodgrassella alvi, cannot metabolize sugar to grow, and yet it still colonized the bee gut when sugar was the only food in the diet and no other bacteria were present.  

By measuring metabolites in the gut, the scientists discovered that the bee synthesizes multiple acids (citric acid, malic acid, 3-hydroxy-3-methylglutaric acid, etc.) that are exported into the gut and were less abundant when S. alvi was present. These results led them to pose an unexpected hypothesis: Does the bee directly enable S. alvi to colonize its gut by furnishing the necessary nutrients? 

Picture proof

Proving this hypothesis was surprisingly difficult, but fortunately, the key expertise was just across the road in the laboratory of Professor Anders Meibom (affiliated with UNIL and EPFL). Professor Meibom and his team are experts in measuring the flux of metabolites in complex environments at nanometers scale resolution by using one of the few NanoSIMS (Nanoscale Secondary Ion Mass Spectrometry) instruments in Europe.

Together the two teams devised an experiment in which microbiota free bees received a special diet of glucose where the natural 12C atoms of carbon in the glucose were replaced with the naturally rare 13C “labelled” isotopes. The bees were then colonized with S. alvi. At the end of the experiment, the fixed guts embarked on a journey, first passing by the electron microscopy facility of UNIL, led by Senior Lecturer Christel Genoud. Then, they moved on to the laboratory of professor Meibom and his NanoSIMS. In the end, the scientists were able to construct a 2-dimensional “image” of the 13C atoms in the gut of the bee, which showed that the S. alvi cells were significantly enriched in 13C, which reflected the 13C enrichment of the acids present in the gut.

To the rescue of the bees

Thus, in a single image, the team was able to show conclusively that the bee synthesizes food for its intestinal bacteria. “This is a wonderful example of cutting-edge, truly interdisciplinary scientific collaboration, which has brought together several scientific units within UNIL and EPFL," comments Anders Meibom. When we work together in this way, there are not many academic environments in the world that have more to offer," adds the professor, who is a pioneer in the application of NanoSIMS technologies to the intransigent questions of biology.

"It's possible that many other gut microorganisms also feed on host-derived compounds," says co-lead author Dr. Andrew Quinn, imagining an extension of this approach to other bacteria. Refocusing on bees: "These results could also explain why bees have such a specialized and conserved gut microbiota." And these mechanisms could play a role in bees' vulnerability to climate change, pesticides, or new pathogens: "Their vulnerability could result from a disruption in this intricate metabolic synergy between the bee and its gut microbiota. We already know that exposure to the herbicide glyphosate makes bees more susceptible to pathogens and reduces the abundance of S. alvi in the gut. Now, armed with these new findings, we're looking for answers to these pressing questions."

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JOURNAL

Nature Microbiology

DOI

10.1038/s41564-023-01572-y 

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

'Host-derived organic acids enable gut colonization of the honey bee symbiont Snodgrassella alvi

ARTICLE PUBLICATION DATE

15-Jan-2024

 

Water molecule discovery contradicts textbook models

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

 

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GRAPHIC REPRESENTATION OF THE LIQUID/AIR INTERFACE IN A SODIUM CHLORIDE SOLUTION, COURTESY YAIR LITMAN

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CREDIT: YAIR LIPMAN

Textbook models will need to be re-drawn after a team of researchers found that water molecules at the surface of salt water are organised differently than previously thought.

Many important reactions related to climate and environmental processes take place where water molecules interface with air. For example, the evaporation of ocean water plays an important role in atmospheric chemistry and climate science. Understanding these reactions is crucial to efforts to mitigate the human effect on our planet.

The distribution of ions at the interface of air and water can affect atmospheric processes. However, a precise understanding of the microscopic reactions at these important interfaces has so far been intensely debated.

In a paper published today in the journal Nature Chemistry, researchers from the University of Cambridge and the Max Planck Institute for Polymer Research in Germany show that ions and water molecules at the surface of most salt-water solutions, known as electrolyte solutions, are organised in a completely different way than traditionally understood. This could lead to better atmospheric chemistry models and other applications.

Technique

The researchers set out to study how water molecules are affected by the distribution of ions at the exact point where air and water meet. Traditionally, this has been done with a technique called vibrational sum-frequency generation (VSFG). With this laser radiation technique, it is possible to measure molecular vibrations directly at these key interfaces. However, although the strength of the signals can be measured, the technique does not measure whether the signals are positive or negative, which has made it difficult to interpret findings in the past. Additionally, using experimental data alone can give ambiguous results.

The team overcame these challenges by utilising a more sophisticated form of VSFG, called heterodyne-detected (HD)-VSFG, to study different electrolyte solutions. They then developed advanced computer models to simulate the interfaces in different scenarios.

The combined results showed that both positively charged ions, called cations, and negatively charged ions, called anions, are depleted from the water/air interface. The cations and anions of simple electrolytes orient water molecules in both up- and down-orientation. This is a reversal of textbook models, which teach that ions form an electrical double layer and orient water molecules in only one direction.

Co-first author Dr Yair Litman, from the Yusuf Hamied Department of Chemistry, said: “Our work demonstrates that the surface of simple electrolyte solutions has a different ion distribution than previously thought and that the ion-enriched subsurface determines how the interface is organised: at the very top there are a few layers of pure water, then an ion-rich layer, then finally the bulk salt solution."

Co-first author Dr Kuo-Yang Chiang of the Max Planck Institute said: “This paper shows that combining high-level HD-VSFG with simulations is an invaluable tool that will contribute to the molecular-level understanding of liquid interfaces.”

Professor Mischa Bonn, who heads the Molecular Spectroscopy department of the Max Planck Institute, added: “These types of interfaces occur everywhere on the planet, so studying them not only helps our fundamental understanding but can also lead to better devices and technologies. We are applying these same methods to study solid/liquid interfaces, which could have potential applications in batteries and energy storage.”

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JOURNAL

Nature Chemistry

DOI

10.1038/s41557-023-01416-6 

ARTICLE TITLE

Surface stratification determines the interfacial water structure of simple electrolyte solutions

ARTICLE PUBLICATION DATE

15-Jan-2024

 

U.S. air pollution rates on the decline but pockets of inequities remain

Decreases more substantial in high-income neighborhoods

Peer-Reviewed Publication

COLUMBIA UNIVERSITY'S MAILMAN SCHOOL OF PUBLIC HEALTH

Over the last decades, air pollution emissions have decreased substantially; however, the magnitude of the change varies by demographics, according to a new study by Columbia University Mailman School of Public Health. The results indicate there are racial/ethnic and socioeconomic disparities in air pollution emissions reductions, particularly in the industry and energy generation sectors. The findings are published in the journal Nature Communications.

The research provides a national investigation of air pollution emission changes in the 40 years following the enactment of the Clean Air Act (CAA). Until now, studies have primarily focused on evaluating air pollution disparities at a single time point, focusing on pollutant concentrations instead of emissions. A focus on emissions, however, has more direct implications for regulations and policies. In this study, the researchers used county-level data to evaluate racial/ethnic and socioeconomic disparities in air pollution emissions changes in the contiguous U.S. from 1970 to 2010.

“The analyses provide insight on the socio-demographic characteristics of counties that have experienced disproportionate decreases in air pollution emissions over the last forty years,” said Yanelli Nunez, PhD, the study’s first author, who is a scientist in the Department of Environmental Health Sciences at Columbia Mailman School of Public Health and affiliated with PSE Healthy Energy. Additionally, by analyzing air pollution emissions, the researchers identified specific pollution source sectors that are potentially important contributors to air pollution exposure disparities.

Nunez and colleagues leveraged air pollution emissions data from the Global Burden of Disease Major Air Pollution Sources inventory to analyze air pollutant emissions from six pollution source sectors: industry (sulfur dioxide), energy (sulfur dioxide and nitrogen oxides), agriculture (ammonia), on-road transportation (nitrogen oxides), commercial (nitrogen oxides), and residential (particles of organic carbon).

On average, national U.S.  air pollution emissions declined substantially from 1970 to 2010 from all source sectors the researchers considered except for ammonia emissions from agriculture and organic carbon particle emissions from the residential sector, which the researchers indicate is primarily from using solid biofuels for indoor heating. The most pronounced emission decreases were observed for sulfur dioxide from industrial and energy generation activities. Nitrogen oxide emissions from transportation, commercial activities, and energy generation decreased moderately.

Despite the overall downward trends for most pollutants, the researchers found that certain populations experienced relatively smaller reductions or even increases in air pollution emissions. For instance, an increase in a county's average Hispanic or Indian American population percentage resulted in a relative increase in sulfur dioxide, nitrogen oxides, and ammonia emissions from the industry, energy generation, and agriculture sectors, respectively. Additionally, an increase in the county median family income was linked with an increase in the magnitude of emissions reductions in every pollution source sector the researchers analyzed, except agriculture. 

“Air pollution emissions do not perfectly capture population air pollution exposure, and we also know that neighborhood-level air pollution inequities are common, which we were not able to analyze in this study given the data at hand,” noted Marianthi-Anna Kioumourtzoglou, ScD, associate professor of environmental health sciences at Columbia Mailman School, and senior author. “In this study, we provide information about potential racial/ethnic and socioeconomic inequalities in air pollution reductions nationwide from major air pollution sources, which can inform regulators and complement local-level analysis.”

“Policies specifically targeting reductions in overburdened populations could support more just reductions in air pollution and reduce disparities in air pollution exposure,” observed Dr. Nunez. “This is an important lesson gained from 53 years of Clean Air Act implementation, which is particularly relevant as we develop policies to transition to renewable energy sources, which will have a collateral impact on air quality and, as a result, on public health.”

Co-authors are Jaime Benavides, Jenni A. Shearston, Misbath Daouda, and Jeff Goldsmith, Columbia University Mailman School of Public Health; Joan Casey, Columbia Mailman School and the University of Washington; Elena Krieger, PSE Healthy Energy; Lucas R.F. Henneman, George Mason University; and Erin McDuffie, University of Washington.

The study was supported by National Institute of Environmental Health Sciences, (P30 ES009089, R01 ES030616, R01 ES028805 and T32 ES007322), The Thomas F. and Kate Miller Jeffress Memorial Trust, Bank of America; and Health Effects Institute (HEI, R-82811201).

Columbia University Mailman School of Public Health

Founded in 1922, the Columbia University Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Columbia Mailman School is the fourth largest recipient of NIH grants among schools of public health. Its nearly 300 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change and health, and public health preparedness. It is a leader in public health education with more than 1,300 graduate students from 55 nations pursuing a variety of master’s and doctoral degree programs. The Columbia Mailman School is also home to numerous world-renowned research centers, including ICAP and the Center for Infection and Immunity. For more information, please visit www.mailman.columbia.edu.

 
 

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JOURNAL

Nature Communications

DOI

10.1038/s41467-023-43492-9