How gut bacteria change after exposure to pesticides

Study in mice hints at possibility for probiotic intervention

Ohio State University

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COLUMBUS, Ohio – While emerging evidence suggests pesticides can be toxic to the mix of microorganisms in the digestive system, a new study is the first to map changes to specific gut bacteria based on interactions between human microbes and insect-killing chemicals observed in the lab and an animal model.

The analysis showed that over a dozen pesticides influence human gut bacteria growth patterns, affect how gut microorganisms process nutrients and camp out inside some bacteria. Researchers say the resulting “atlas” of molecular mechanisms, which they have made publicly available, is a resource that can be leveraged for targeted studies on relevant diseases and potential therapeutic strategies.

Experiments in mice showed that one gut bacteria species provides some protection against pesticide toxicity, hinting at the possibility for a probiotic approach to preventing some of their damaging health effects – in this case, inflammation.

“We’ve provided further understanding of how pesticides or environmental pollutants impact human health by modulating an important collection of microorganisms,” said senior author Jiangjiang Zhu, associate professor of human sciences at The Ohio State University. 

“We also identified certain microbes that can degrade, remove or clear some of these pesticides from biological systems, which may be potential therapeutics in the future to help people clear toxicity from the gut that have been introduced by food and water intake, providing better solutions for human health.”

The research was published recently in Nature Communications.

The findings are based on investigating the interactions in the lab between 18 pesticide compounds selected for their widespread agricultural use around the world and 17 species from four major bacterial domains in the human gut that are associated with either health maintenance or disease states. Among the pesticides included were DDT (banned in the United States but used indoors in some countries to control malaria-carrying mosquitoes), atrazine, permethrin and chlorpyrifos. Even with limitations on their use, residues from some legacy pesticides still circulate in soil and water, Zhu said.

“We grew bacteria in culture and exposed them to relevant concentrations of pesticides to see how microbes responded to those pesticide exposures,” said first author Li Chen, a senior research associate in Zhu’s lab, who managed over 10,000 samples that were analyzed in the study.

Based on the findings, the team developed a bacteria-pesticide interaction network detailing which pesticides either promoted or inhibited bacterial growth and the bacteria that absorbed pesticide chemicals – an indication of one way exposure to pesticides can be prolonged in the body.  

“Most previous environmental health studies reported that pesticide contamination affects the overall composition of gut bacteria,” Chen said. “We showed those pesticides really can affect specific gut bacteria and detailed how these changes will affect the general composition.”

The analysis identified specific metabolic changes in 306 pesticide-gut microbe pairs, leading to examination of how those altered growth patterns and accumulation of chemicals affected metabolites – the molecular products of biochemical reactions that break down nutrients to produce energy and perform other essential functions. Metabolites have numerous roles, from altering the metabolic process itself to sending signals related to multiple cell functions and immune system activation.

In addition, the study team performed a separate analysis zeroing in on another important class of molecules that can be produced by gut microbes – the fatty, oily and waxy compounds called lipids that are essential to many body functions.

Researchers also studied the effects of pesticide exposure in healthy mice first given antibiotics to clear their digestive systems of microbes. The team introduced Bacteroides ovatus, a common strain of human gut bacteria, to one group of mice and compared them to controls after four weeks of exposure to pesticides.

Results verified what was seen in the lab, showing that pesticides generated inflammation in multiple organs in the mice and that the presence of the introduced bacteria after chemical exposure set off a range of changes in metabolic activity and lipid production. Specifically, an increase in some classes of lipids inhibited the signaling pathway of a protein linked to oxidative stress.

“We identified microbes that may modulate the toxic effect of pesticides to the host by somehow buffering the inflammation process,” said Zhu, also an investigator in The Ohio State University Comprehensive Cancer Center Molecular Carcinogenesis and Chemoprevention Research Program. 

“We know inflammation is generally bad for the body. If something toxic is going to induce it, and there are other molecules that can counteract that agent, you may have a solution to intervene or prevent larger-scale damage.”

In the next phrase of this work, Zhu’s lab plans to further explain where metabolic changes to gut microbes fit into various health and disease conditions after pesticide exposure. He expects other scientists will do the same.

“We are mapping out this central interaction between pesticides and gut microbes. And then other labs can leverage what we have discovered – for example, after exposure to a pesticide, gut microbe reactions may lead to downstream consequences that contribute to disease research and eventually help with predicting targets or identifying an intervention strategy,” he said.

This research was supported by the National Institute of General Medical Sciences. Zhu is also supported by the Provost’s Scarlet and Gray Associate Professor Program at Ohio State. 

Additional co-authors include Chao Guo, Huan Zhang, Shiqi Zhang, Andrew Gold, Ming Hu and Dayong Wu, all of Ohio State; Hong Yan and Caroline Johnson of Yale University; Shanshan Di and Xinquan Wang of Zhejiang Academy in Hangzhou, China; and Yu Wang of Johns Hopkins University.

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Contact: Jiangjiang (Chris) Zhu, Zhu.2484@osu.edu

Written by Emily Caldwell, Caldwell.151@osu.edu; 614-292-8152

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Journal

Nature Communications

DOI

10.1038/s41467-025-59747-6 

Article Title

Mapping pesticide-induced metabolic alterations in human gut bacteria

New research reveals significant wage gap for Latina workers in Santa Barbara, Santa Cruz and Ventura counties

University of California - Los Angeles

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Key takeaways:

• Across California, 59% of Latinas participate in the workforce. 

• Latinas tend to get paid less than other women of color, white women and white men in Santa Barbara, Santa Cruz and Ventura counties.

• When Latinas are underpaid, it affects families’ ability to access housing, education and health care, and plan for retirement. The consequences of their financial challenges ripple across the entire region.

Latinas in California’s Santa Barbara, Santa Cruz and Ventura counties earn only 47-50 cents for every dollar earned by a non-Hispanic white man, according to a new study.

The analysis, led by UCLA, UC Santa Cruz and Cal State Channel Islands researchers, looked at data from the United States Census Bureau’s 2023 American Community Survey (ACS) and thousands of surveys collected by the researchers, primarily focused on Santa Barbara, Santa Cruz and Ventura workers aged 18 to 34. The findings were revealed in a series of new, comprehensive research reports highlighting educational access, wage gaps, scheduling and gender inequalities for workers.

“On average, men make more than women. However, hourly earnings are especially low for Latinas, who tend to get paid less than other women of color, white women and white men,” said Veronica Terriquez, research author, director of the UCLA Chicano Studies Research Center (CSRC) and co-founder of the Latina Futures 2050 Lab, an initiative spearheaded by the CSRC. “This research matters because oftentimes Latinas are unseen, unheard and get concentrated in low-paying jobs. These low wages are a serious problem because unfair wages impact entire communities.”

Focusing on the Latina experience is essential to documenting their livelihoods because across California, 59% of Latinas participate in the workforce. Latinas have also historically been left out of research studies, creating knowledge gaps for legislators and other officials in charge of making and amending laws for all California residents, Terriquez said. 

Santa Barbara and Ventura counties

Terriquez and Jeannette Ciudad-Real, an undergraduate student researcher at the CSRC, found that in 2023, Latinas represented 46% of the female civilian labor force in Santa Barbara County, compared to 43% of non-Hispanic white women. In Ventura County, Latinas represented 42% of the female civilian labor force, compared to 43% non-Hispanic white women.

Despite the high percentages of Latinas in these labor forces, they earned 50 cents for every dollar a non-Hispanic white man earned in the Ventura area, and 47 cents in Santa Barbara. 

“Differences in educational attainment and occupational status explain part of the wage gap. When compared to white residents, Latinos and Latinas tend to have poorer access to high-quality K-12 education and universities and colleges that grant bachelor’s degrees,” the researchers wrote in their report. “Additionally, gender discrimination and stereotyping play a part in defining career paths and contribute to lower pay for Latinas relative to men even within the same occupational categories.”

Read all of the Santa Barbara and Ventura County reports here.

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Santa Cruz County findings

Terriquez and Sylvanna Falcón, professor in UC Santa Cruz’s Department of Latin American and Latino Studies, looked at ACS data from 2019-2023 that analyzed Latinas’ participation in the civilian labor force and their hourly earnings in Santa Cruz County. They found that Latinas earned 50 cents for every dollar a non-Hispanic white man earned. Latinas also made up approximately 34% of the female civilian labor force in Santa Cruz County, compared to 55% non-Hispanic white women.

“Many Latinas are the primary earners in their households, and they contribute significantly as taxpayers and community members. When they are underpaid, the impact extends beyond individual workers, affecting families’ ability to access housing, education and health care and to plan for retirement,” the authors wrote in their analysis. “The consequences of their financial challenges ripple across the entire region.” 

Read all Santa Cruz County reports here.

Findings and recommendations

Among the researchers’ recommendations are comprehensive policy solutions that include reducing occupational segregation, expanding support for family care, creating pathways to citizenship and strengthening protections against workplace discrimination. 

Santa Barbara, Ventura and Santa Cruz’s civic and business leadership can play a role in advancing fair and equitable wages for Latinas and all other workers, Terriquez and Falcón said. 

This research is part of the Latina Futures 2050 Lab, spearheaded by the CSRC in partnership with the UCLA Latino Policy & Politics Institute (LPPI); the UCLA Labor Center’s Prosperity, Opportunity and Worker Equity Reimagined in Workforce Development team; the Center for Labor and Community and the Dolores Huerta Research Center for the Americas, both housed at UC Santa Cruz; and Cal State Channel Islands.

 

Study reveals uneven land sinking across New Orleans, raising flood-risk concerns

Tulane University

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Parts of New Orleans and its surrounding wetlands are gradually sinking, and while most of the city remains stable, a new study from Tulane University researchers suggests that sections of the region’s $15 billion post-Katrina flood protection system may need regular upgrades to outpace long-term land subsidence.

The study, published in Science Advances, used satellite radar data to track subtle shifts in ground elevation across Greater New Orleans between 2002 and 2020. The study found that some neighborhoods, wetlands and even sections of floodwalls are sinking by more than an inch per year — with some areas experiencing up to 47 millimeters (nearly 2 inches) of elevation loss annually.

“In a city like New Orleans, where much of the land is already near sea level, even minor drops in elevation can increase flood risk,” said Simone Fiaschi, lead author of the study and a former researcher with Tulane’s Department of River-Coastal Science and Engineering, now employed at TRE-Altamira.

The findings underscore how both natural and human-driven forces are reshaping the city’s landscape. Causes of the sinking — known as subsidence — include natural soil compaction, groundwater pumping, industrial development and the legacy of wetland drainage for urban growth.

The study used a remote sensing technique called InSAR (Interferometric Synthetic Aperture Radar), which detects millimeter-scale changes in land surface elevation by comparing satellite radar images taken over time. This allowed the researchers to build the most detailed map yet of vertical land motion in New Orleans — including areas like wetlands that had previously lacked reliable data.

Among the most troubling findings: some of the concrete floodwalls and levees built to protect the city after Katrina are themselves sinking. In a few cases, parts of the Hurricane and Storm Damage Risk Reduction System (HSDRRS) are losing elevation faster than sea levels are rising, reducing their capacity to block storm surges.

“These results are a wake-up call,” said co-author Prof. Mead Allison, also of Tulane. “We need ongoing monitoring and maintenance to ensure that our flood defenses don’t lose their level of protection beneath us.”

The study also found pockets of sinking around industrial sites, the airport and newer residential developments — areas where soil compression and groundwater withdrawal are likely contributors. In contrast, some areas such as parts of Michoud showed modest land uplift, likely due to the halt of industrial groundwater pumping and recovery of the water table.

Wetlands east of the city, long known for their ecological importance, are also sinking rapidly in places. In some spots, the loss of elevation could transform marshes into open water within a decade if trends continue. This has implications not just for wildlife but also for storm protection, as wetlands help buffer storm surges.

New Orleans, much of which lies below sea level, relies on an elaborate system of levees, pumps and drainage canals to keep water out. As sea levels rise and the ground sinks, the margin for error narrows.

Experts say that without sustained monitoring, including satellite data and ground-based measurements, it’s difficult to know where to reinforce levees or how to plan for future storms.

“This research shows that land movement isn’t uniform, and understanding these patterns is crucial for protecting lives and property in a city where inches truly matter,” Fiaschi said. "However, it's crucial to remember that our results still require careful ground-truthing. This is especially true for critical areas like the floodwalls, where on-site verification was not possible during this project."

The study highlights the potential of satellite monitoring to guide infrastructure maintenance and urban planning, not just in New Orleans but in coastal cities worldwide facing similar challenges.

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Journal

Science Advances

DOI

10.1126/sciadv.adt5046 

Subject of Research

Not applicable

Article Title

Vertical land motion in Greater New Orleans: insights into underlying drivers and impact to flood protection infrastructure

Article Publication Date

27-Jun-2025

 

How urea forms spontaneously

Urea is considered a possible key molecule in the origin of life. ETH researchers have discovered a previously unknown way in which this building block can form spontaneously on aqueous surfaces without the need for any additional energy

ETH Zurich

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image: 

Graphical representation of urea formation in a droplet 

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Credit: Luis Quintero / ETH Zürich

Urea is one of the most important industrial chemicals produced worldwide. It is used as a fertiliser, for the production of synthetic resins and explosives and as a fuel additive for cleaning car exhaust gases. Urea is also believed to be a potential key building block for the formation of biological molecules such as RNA and DNA in connection with the question of the origin of life (see ETH News from 28 June 2023). Until now, the origin of urea itself on Early Earth has not been conclusively clarified.

A research team led by Ruth Signorell, Professor of Physical Chemistry at ETH Zurich, has discovered a previously unknown reaction pathway for the formation of urea that could provide an answer. The external pagestudy has just been published in the journal Science.

Chemistry on the water surface

Either high pressures and temperatures or chemical catalysts are needed for the industrial production of urea from ammonia (NH₃) and carbon dioxide (CO₂). Enzymes enable the same reaction to take place in humans and animals, removing toxic ammonia from the breakdown of proteins such as urea. As this simple molecule contains nitrogen as well as carbon and probably existed on the uninhabited Early Earth, many researchers view urea as a possible precursor for complex biomolecules.

“In our study, we show one way in which urea could have formed on the prebiotic Earth,” says Signorell – “namely where water molecules interact with atmospheric gases: on the water surface.”

Reactor on the edge of a droplet

Signorell's team studied tiny water droplets such as those found in sea spray and fine mist. The researchers observed that urea can form spontaneously from carbon dioxide (CO₂) and ammonia (NH₃) in the surface layer of the droplets under ambient conditions. The physical interface between air and liquid creates a special chemical environment at the water surface that makes the spontaneous reaction possible.

As a droplet has a very large surface area in relation to its volume, chemical reactions mainly take place near this surface. Chemical concentration gradients form in this area, which acts like a microscopic reactor. The pH gradient across the interfacial layer of the water droplets creates the required acidic environment, which opens unconventional pathways that would otherwise not take place in liquids.

“The remarkable aspect of this reaction is that it takes place under ambient conditions without any external energy,” explains Mercede Mohajer Azizbaig, one of the two first authors. This not only makes the process interesting from a technical perspective but also provides valuable insights into processes that could be significant for evolution. 

A window into the early days of the Earth

The origin of life is currently the subject of a great deal of wide-ranging research, with different approaches being explored. First author Pallab Basuri explains: “Given such a controversial field of research, it was important for us to back up our observations.” Theoretical calculations by co-authors Evangelos Miliordos and Andrei Evdokimov from Auburn University supported the experimental findings and confirmed that the urea reaction on the droplets takes place without any external energy supply.

The results suggest that this natural reaction could also have been possible in the atmosphere of the Early Earth - an atmosphere that was rich in CO₂ and probably contained small traces of ammonia. In such environments, aqueous aerosols or fog droplets could have acted as natural reactors in which precursor molecules such as urea were formed. “Our study shows how seemingly mundane interfaces can become dynamic reaction spaces, suggesting that biological molecules may have a more common origin than was previously thought,” says Signorell.

In the long term, the direct reaction of CO₂ and ammonia under ambient conditions could also have potential for the climate-friendly production of urea and downstream products.

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Journal

Science

DOI

10.1126/science.adv2362 

Subject of Research

Not applicable

Article Title

Spontaneous formation of urea from carbon dioxide and ammonia in aqueous droplets

Article Publication Date

26-Jun-2025

 

Device study offers hopes for spinal cord injuries

An implantable electronic device has restored movement following spinal cord injury in an animal study.

University of Auckland

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Spinal cord injuries are currently incurable with devastating effects on people’s lives, but now a trial at Waipapa Taumata Rau, University of Auckland offers hope for an effective treatment.

Spinal cord injuries shatter the signal between the brain and body, often resulting in a loss of function.“Unlike a cut on the skin, which typically heals on its own, the spinal cord does not regenerate effectively, making these injuries devastating and currently incurable,” says lead researcher Dr Bruce Harland, a senior research fellow in the School of Pharmacy at Waipapa Taumata Rau, University of Auckland.

Before birth, and to a lesser extent afterwards, naturally occurring electric fields play a vital role in early nervous system development, encouraging and guiding the growth of nerve tissue along the spinal cord. Scientists are now harnessing this same electrical guidance system in the lab.An implantable electronic device has restored movement following spinal cord injury in an animal study, raising hopes for an effective treatment for humans and even their pets.

“We developed an ultra-thin implant designed to sit directly on the spinal cord, precisely positioned over the injury site in rats,” Dr Harland says.

The device delivers a carefully controlled electrical current across the injury site. “The aim is to stimulate healing so people can recover functions lost through spinal-cord injury,” Professor Darren Svirskis, director of the CatWalk Cure Programme at the University’s School of Pharmacy says.

Unlike humans, rats have a greater capacity for spontaneous recovery after spinal cord injury, which allowed researchers to compare natural healing with healing supported by electrical stimulation.

After four weeks, animals that received daily electric field treatment showed improved movement compared with those who did not.

Throughout the 12-week study, they responded more quickly to gentle touch.

“This indicates that the treatment supported recovery of both movement and sensation,” Harland says. “Just as importantly, our analysis confirmed that the treatment did not cause inflammation or other damage to the spinal cord, demonstrating that it was not only effective but also safe.”

This new study, published in a leading journal, has come out of a partnership between the University of Auckland and Chalmers University of Technology in Sweden. See Nature Communications.

“Long term, the goal is to transform this technology into a medical device that could benefit people living with these life-changing spinal-cord injuries,” says Professor Maria Asplund of Chalmers University of Technology.

“This study offers an exciting proof of concept showing that electric field treatment can support recovery after spinal cord injury,” says doctoral student Lukas Matter, also from Chalmers University.

The next step is to explore how different doses, including the strength, frequency, and duration of the treatment, affect recovery, to discover the most effective recipe for spinal-cord repair.

• Read the study.
• Find out about animal-based research at the University of Auckland.

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Journal

Nature Communications

DOI

10.1038/s41467-025-60332-0 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Daily electric field treatment improves functional outcomes after thoracic contusion spinal cord injury in rats

Article Publication Date

26-Jun-2025

 

Malnutrition in children rises when economy drops

Study with data from over 1.6 million children across 68 low and middle-income countries shows that early-life exposure to economic shocks is linked to an increased risk of malnutrition, including overweight and obesity

Barcelona Institute for Global Health (ISGlobal)

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Even small drops in national income can significantly increase the risk of various forms of childhood malnutrition- not only undernutrition but also overweight and obesity, shows a study led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by “la Caixa” Foundation. The study, published in Lancet Global Health, identifies pregnancy and the first 1,000 days of life as especially vulnerable periods where targeted interventions can make a big difference.

One in four children worldwide lives in severe food poverty. And many low- and middle-income countries (LMICs) now face an increasing double burden of malnutrition, characterised by the coexistence of undernutrition alongside overweight or obesity.

“Given the multiple crises the world is currently facing, we need to better understand how economic shocks and poverty influence malnutrition in children, in order to better design interventions and prevention strategies,” says Davide Rasella, ICREA researcher at ISGlobal and coordinator of the study.

A close look at economic downturns and child malnutrition

The authors analysed data from over 1.6 million children across 68 LMICs to understand how early exposure to economic downturns affects nutrition. They combined 230 national household surveys with economic data from the World Inequality Database. This allowed them to track each child from birth to the first 1,000 days of life, and to identify economic downturns across different income groups within each country.  

“Our analysis is the first to account for economic heterogeneity within each country and look at critical time windows and different forms of malnutrition, including overweight and obesity,” says Natanael Silva, predoctoral researcher at ISGlobal and first author of the study.

The first 1,000 days of life 

The researchers used the child’s height, weight and age to identify different forms of malnutrition, sometimes combined in the same child: stunting (too short for their age), wasting (too thin for their height), overweight and obesity. 

The analysis revealed the following patterns:   

A fall in income during the year a child was born raised the risk of stunting, especially when the economic drop was severe. Income shocks at birth were also associated with an increased risk of both wasting and stunting in the same child, suggesting that economic instability during pregnancy can have profound effects on early life.

Income shocks in the year of the interview were mainly associated with child wasting, defined as a rapid loss of weight, reflecting short-term changes in diet quality or quantity, as well as illnesses.

Children who experienced an economic shock during their first 1,000 days of life (a critical period for growth) had a much higher risk of becoming both stunted and overweight — a 30% increase in risk. Even mild economic downturns were linked to increased risks of this double burden of malnutrition. 

Finally, the effects varied by income level: income shocks generally had a greater adverse impact on undernutrition among the poorest, while wealthier households also saw an increase in obesity and overweight. 

“Our findings show that income shocks can significantly increase the risk of various forms of childhood malnutrition, and help identify critical windows for action,” says Rasella. The authors urge policymakers to develop targeted interventions to safeguard maternal and child nutrition, especially during times of economic hardship.

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Journal

The Lancet Global Health

DOI

10.1016/S2214-109X(25)00153-6 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Early-life exposure to economic shocks and association with childhood malnutrition: a pooled analysis of 230 nationwide surveys from 68 low- and middle-income countries

Article Publication Date

27-Jun-2025