Tag: PLOS

Categories : Cancer Lab Tests and ImagingTags : Leave a comment

Blood Test Trends may Help Identify Patients at Increased Risk of Cancer

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Among patients with unexplained weight loss, changes over time in routine blood test results were associated with overall and site-specific cancer diagnoses

Photo: Pixabay

Blood test trends alongside unexplained weight loss can improve triage for cancer testing, according to a study by Brian Nicholson and colleagues from the University of Oxford, UK, published September 17th in the open access journal PLOS Medicine.

Abnormal blood test results, such as low haemoglobin or increased platelet counts, can provide clues about a patient’s risk of developing cancer. However, monitoring trends over repeat tests could provide further clues in some instances, by identifying cancer-related changes in blood test results that do not appear abnormal. Assessing patterns in blood test abnormalities and trends alongside unexplained weight loss could enhance cancer risk assessment and support earlier diagnosis.

In this study, researchers examined trends in blood test results among patients with unexplained weight loss, a common non-specific symptom associated with multiple cancer types. The goal was to determine whether trends in 26 commonly used blood tests in primary care could improve cancer risk stratification compared to abnormalities on single blood tests.

Among the more than 275 000 patients included in the study, nearly 14 000 were subsequently diagnosed with cancer within six months, allowing researchers to relate abnormalities on single tests and trends over repeat blood tests to cancer diagnosis. Overall, 23 blood test trends were associated with overall cancer risk. Several abnormalities were also associated with specific cancer types. After accounting for age and sex, several blood test trends were more discriminative for cancer diagnosis than individual abnormal test results. For example, trends in white blood count and neutrophils were linked to lung cancer while trends in red blood cell count, haematocrit, and platelet-to-lymphocyte ratio were associated with prostate cancer.

The findings suggest that monitoring changes in routine blood test results in patients with unexplained weight loss could identify patients in primary care who would benefit from additional cancer testing.

Author Brian Nicholson adds, “We show how blood test results are made more accurate for cancer by adding patient age and sex. This relatively simple calculation could easily be performed at the laboratory.”

Author Pradeep Virdee states, “In some instances, monitoring how a patient’s blood test results change over time could offer further value. We plan to assess how well blood test abnormalities and trends inform cancer risk in patients with other types of non-specific symptoms, such as fatigue and vomiting.”

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Categories : Metabolic DisordersTags :

Women with Type 2 Diabetes More Likely to Develop Mental Health Conditions

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Men, on the other hand, experience more cardiovascular and renal disease post-diagnosis

Photo by isens usa on Unsplash

In the years following type 2 diabetes diagnosis, women are more likely to develop mental health conditions, while men are more likely to develop cardiovascular and renal complications, according to a study published August 25th in the open access journal PLOS Medicine by Fabiola Eto from Queen Mary University of London, UK, and colleagues.

Type 2 diabetes, a metabolic disorder defined by high blood sugar, results from resistance to or insufficient production of insulin. Globally, type 2 diabetes affects about 536.6 million people between 20 and 79 years old, or 10.5% of the population; by 2045, this number is expected to rise to 700 million. Cardiovascular disease, end-stage renal disease, and mental health disorders like depression and anxiety are all associated with type 2 diabetes. Women and men are known to experience these conditions differently, but research has not yet described the disease trajectories according to sex and age in people with type 2 diabetes.

Eto and colleagues examined anonymized health records from 28,720 men and women in the UK who developed type 2 diabetes between 2010 and 2020. Men constituted 62% of the cohort with a median age of 54 at type 2 diabetes onset; women were on average older at diagnosis.

In the years following diagnosis, 39% of the participants experienced at least one significant health event. The events’ trajectory and timing differed by sex. For example: women were more likely to develop mental health conditions post-diagnosis (8.1% compared to 5.3%) and to experience trajectories culminating in death, while men showed higher proportions of cardiovascular disease (8.4% compared to 5.3%), end-stage renal disease, and hypertension (21.1% compared to 20.2%). The researchers noted that on average, women used more health services and long-term prescriptions than men, which may contribute to the increased diagnoses.

There were several similarities between the sexes as well. Both women and men who had a combination of type 2 diabetes and a mental health condition experienced premature mortality compared to other trajectories. Across all age groups and sexes, hypertension was the most frequent event following type 2 diabetes.

Current UK medical guidelines lack sex-specific prevention strategies and management for type 2 diabetes and comorbidities, especially mental health conditions. This study highlights the need for healthcare interventions differentiated by characteristics like sex and age.

The authors add, “One of the clearest signals in our data was the sex difference. Younger women with type 2 diabetes were showing mental health complications earlier and more often than we expected, which suggests routine psychological screening should be incorporated into standard diabetes care. For men, the pattern looked different: cardiovascular and kidney risks tended to emerge earlier, pointing to a need for earlier monitoring and stronger strategies to support men’s engagement with their treatment over time.”

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Categories : IT in HealthcareTags :

Incorrect AI Advice is a Blind Spot – Even for Doctors

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 New study highlights potential challenges for using automated tools in healthcare

Photo by Accuray on Unsplash

In experiments in which physicians made decisions about treating hypothetical patients, the physicians tended to trust incorrect advice presented as being generated by artificial intelligence (AI), even after given the opportunity to notice that patient recovery data contradicted the recommendations. Aranzazu Vinas of the University of the Basque Country, Spain, and colleagues present these findings in the open-access journal PLOS Digital Health. 

AI systems can help physicians categorise patients according to their different care needs, such as whether a patient is more or less likely to benefit from a certain treatment. Since these systems are not perfect, they are meant to be used as suggestions, with potential errors caught and corrected by physicians.

 Prior research has shown that, in general, people struggle to notice and correct mistakes made by AI. To explore how this challenge may extend to physicians, Vinas and colleagues analysed data from 223 physicians who anonymously participated in online experiments.

 The physicians were asked to imagine they had the option to treat patients for a rare disease using a not-yet-proven treatment still under development. They were told that an AI system had identified which patients were more or less likely to benefit from the treatment. The physicians then chose which patients to treat, and after being presented with data on patient recovery, rated their perceptions of how reliable the AI was.

 Crucially, the actual effectiveness of the hypothetical treatment did not align with the AI recommendations. In one experiment, the treatment was equally moderately effective for all patients, and in a second experiment, it was equally ineffective for all.

 However, in both experiments, the physicians tended to rate the AI system as reliable and apparently did not use the patient recovery data to conclude that the AI recommendations were incorrect. In the second experiment, the physicians did not realise that the treatment was entirely ineffective.

These findings highlight potential challenges for incorporating AI-based classification into healthcare. Future research could build on this study, such as by developing and testing strategies and protocols that could increase human critical thinking and detection of AI errors, in order to maximize the benefits of the human-AI collaboration while minimising potential errors.”

Lead author Aranzazu Vinas notes: ” In both experiments, physicians mostly trusted the AI’s classifications and had trouble learning from the feedback. Furthermore, in the second experiment, professionals did not notice that the treatment was completely ineffective.”

 Co-author Helena Matute adds, “People tend to say that there is always a human controlling the algorithm, but our experiments show that doctors (as well as anyone else) have problems in learning from the available evidence when it contradicts the suggestions of an algorithm.”

Co-author Fernando Blanco summarizes: “It is important to investigate the errors that humans (including doctors) make when working with algorithms, in order to learn how to minimize the problems that arise from them.”

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Contact: Aranzazu Vinas, aranzazu.vinas@ehu.eus

Image Caption: Doctors working on an AI-support system

Image Credit: Photo by Accuray on Unsplash. Free to share under the Unsplash license.

High-Resolution Image Link: https://unsplash.com/photos/a-few-men-looking-at-a-computer-screen-S34fEzWT6eE

Categories : OphthalmologyTags :

Proteins in Blood Could Help Predict Retinal Degeneration in Diabetics

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A model using 71 proteins associated with retinal degradation could predict risk in diabetics

Plasma proteomic signatures for early risk stratification of diabetic retinal neurodegeneration.
Credit: Wei Wang and Huangdong Li / Zhongshan Ophthalmic Center, Sun Yat-sen University (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)

An AI-assisted model based on 71 different blood proteins could help doctors better predict retinal degeneration in diabetic patients before symptoms occur, according to a study published June 2nd in the open access journal PLOS Medicine by Huangdong Li from the Guangdong Provincial Clinical Research Center for Ocular Diseases in Guangzhou, China, and colleagues.

More than half a billion people around the world are now affected by diabetes. People with the disease are at risk of different neurodegenerative conditions, including the breakdown of the retina, the part of the eye that detects light, in a condition called diabetic retinal neurodegeneration (DRN). It can cause severe visual impairment and vision loss, and scientists believe that DRN is a “window” into the diabetic degeneration of other parts of the nervous system, including cognitive impairment and dementia, as well as degradation of nerves in peripheral areas like the fingers and toes.

Unfortunately, DRN is only detected after symptoms appear, when damage is already irreversible. To better predict who might suffer from DRN and when, the researchers sampled the blood plasma from 1492 patients in the Guangzhou Diabetic Eye Study with type 2 diabetes who did not yet have DRN, and examined the eyes of 1218 of them through scans over a six-year period. They compared their results with another 502 people with diabetes in the United Kingdom BioBank.

The researchers identified 71 different plasma proteins associated with DRN. The proteins were part of cell pathways for processes like inflammation and cellular maintenance. Using machine learning, the scientists used the protein levels in plasma to develop a predictive model called Pro-DRN which was able to improve on the best-performing model by 26 percent. The scientists have already put the model online to allow doctors to assess the risk. While Pro-DRN is based on plasma protein levels and relies on associations between protein levels and DRN and not direct causes, the authors hope that it could help doctors predict and potentially prevent neurodegeneration, using a simple blood test analysed by AI.

The authors add, “Our study suggests that early retinal nerve damage in diabetes leaves measurable signals in the blood. By combining plasma proteomics, longitudinal retinal imaging, and explainable AI, Pro-DRN may help move diabetic eye care from detecting established damage toward earlier, molecularly informed risk stratification, so that closer monitoring and future neuroprotective interventions can be directed to the people most likely to benefit.”

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Categories : Medical Research & Technology NeurologyTags :

Patient Cryopreservation Given a One in Four Chance of Working

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Opinions ranged widely, with some physicians concerned that preparation for preservation could interfere with best practices for a patient’s care.

AI image of a brain being cryogenically preserved. [Ed: The patient better have some hefty medical aid to pay for a new body in the year 3000…]

Surveyed US physicians believed preservation has a one in four chance of working, though opinions amongst physicians varied. Ariel Zeleznikow-Johnston of Monash University, Australia, and colleagues present their findings in the study, published on May 20, 2026 in the open-access journal PLOS One.

It’s unclear whether there is a consensus amongst doctors regarding preservation – the storing of bodies at extremely low temperatures, or using preservative chemicals, in the hopes of future revival. Preservation is not the only way in which physicians have to balance concerns about unproven treatments with patients’ preferences, but it is one with high stakes as it pertains to the end of someone’s life. The technologies necessary to revive someone have not yet been realised, though current preservation organisations report several hundred patients preserved globally, with thousands more signed up for future preservation.

In this study, Zeleznikow-Johnston and colleagues conducted a survey of over 300 physicians, nearly half of whom were primary care providers, the rest being various kinds of specialists including neurologists, intensive care doctors, anaesthesiologists, and doctors who specialise in palliative care. The survey was designed to address three main themes: the perceived feasibility of preservation procedures, clinical interventions that could improve preservation outcomes, and the ethical and legal standing of preservation as an end-of-life option.

About one in four of the physicians said they believed it was plausible, or even very plausible, that someone could be revived in the future after preservation. Just under half said it was unlikely. Neurosurgeons, on average, rated the possibility of revival highest, though most of the other specialties showed a wide spread of opinions that slanted more towards scepticism.

The way doctors are most likely to interact with preservation in their professional capacity is in the choices a patient may make for end-of-life care. A majority of physicians supported prescribing anti-coagulants to dying patients, which could help with the quality of preservation. However, fewer respondents were comfortable with more extreme procedures, such as patients going through medically assisted death and opting to begin the preservation before cardiac arrest. The doctors who most commonly have conversations about end-of-life care were overall more supportive of this kind of choice. About one in five doctors were concerned that decisions to increase the odds of successful cryopreservation would clash with providing the best standards of care.

Currently, pre-cardiac arrest preservation in humans is, to the best of our knowledge, not legally permitted anywhere in the world, but if the technology develops further, may become an issue healthcare professionals must grapple with. The authors emphasise that clarifying the clinical, legal, and ethical frameworks for use of preservation as an end-of life procedure is important, and note that the speculative nature of the findings should be carefully considered.

Zeleznikow-Johnston adds: “A lot of physician hesitancy may come from simple unfamiliarity with the scientific basis of modern preservation methods. The doctors who have actually thought about this – and who regularly sit with dying patients – tend to be more receptive, not less.”

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Categories : Gastrointestinal NeurologyTags :

Head Impacts Associated with Altered Gut Microbiome in Football Players

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Non-concussive head impacts correlated with changes to the gut microbiome on following days, in pilot study tracking six US collegiate football players over one season

Image credit: Rich Barnes / Colgate Athletics, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

Non-concussive head impacts – hits to the head that don’t cause clinically detectable symptoms – are correlated with subsequent changes to the gut microbiome in a small sample of US collegiate football players, according to a new study published May 6, 2026, in the open-access journal PLOS One by Ahmet Ay and Kenneth Douglas Belanger of Colgate University, USA, and colleagues.

Non-concussive head impacts are common in American football, with players experiencing between 100 and 1000 across a season. While research has shown that full concussions can disrupt the gut microbiome – which regulates inflammation and the neuroimmune system – whether sub-concussive hits might produce similar effects had not been investigated.

In the new study, researchers tracked six NCAA Division I American football players across a competition season, beginning during preseason training. Their on-field activity profiles were monitored using GPS units and head impacts were tracked using a helmet-based sensor system; 226 faecal samples were analysed for their microbiome composition; and participants completed lifestyle questionnaires after each sample collection.

The researchers found that microbial diversity changed within two to three days after a substantial head impact. Specifically, certain bacteria – including the order Coriobacteriales, the family Prevotellaceae, and the genus Prevotella – tended to decrease in abundance while the genus Ruminococcus increased. In previous studies, these changes have correlated with brain injury and inflammation.

The athletes’ gut microbiomes also changed significantly over the course of the season, with mathematical modelling suggesting that the cumulative effects of non-concussive head impacts was likely associated with this shift, even after accounting for 15 potentially confounding factors including diet changes, exercise intensity, sleep, and stress.

The study is limited by its small sample size and lack of a control group, with its design meaning findings could only establish correlation but not causation. However, the authors conclude that even sub-symptomatic head impacts might affect the gut microbiome, both in the immediate aftermath of injury and over a longer time course in athletes who experience multiple impacts. 

Ken Belanger adds: “As far as we are aware, this is the first study to examine connections between head impacts and the composition of the gut microbiome – the complex community of bacteria and other organisms within the digestive system.”

“Our results provide evidence that even head impacts that do not result in a concussion or other reported symptoms may influence the microbes present within the gut, both in the short- and longer-term. Determining what causes these changes and whether they have a positive or negative influence on recovery from head injury will require further investigation.”

“Our research highlights the importance of thinking integratively about the interactions between the gut and the brain. We are only beginning to scratch the surface in our understanding of how these complex organs and organ systems communicate with and affect each other.”

Aziz Zafar adds: “After having only heard of the complicated interplay between neuronal inflammation and the gut microbiome, I found it to be such an exciting scientific experience to explore that interplay in the context of head impacts.”

Zachary Pelland adds: “It has been an amazing privilege to work so deeply on a personally and scientifically meaningful project which could not have happened without immeasurable support across academic departments, athletics, administration, and alumni at Colgate University.” 

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Categories : Mental HealthTags :

People with Poor Mental Health Have Worse Healthcare Experiences

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Poorer mental health was associated with worse reported care and less trust in the healthcare system

Photo by Alex Green on Pexels

People with self-reported poorer mental health also report worse quality of care and lower confidence in healthcare systems, according to a study published May 5th in the open-access journal PLOS Medicine by Margaret E. Kruk from Washington University in St. Louis, U.S., and colleagues.

Rates of depression and anxiety have increased worldwide since the COVID-19 pandemic, and more people are pursuing mental health treatment as a result. However, there is limited up-to-date data describing how these individuals seek out and receive care. Detailed, population-level information can help healthcare systems meet this growing population’s needs.

To make a start on gathering this data, Kruk and her colleagues surveyed 32 419 adults in 18 high-, low-, and medium-income countries. More than 1000 people from each country responded. Participants self-reported data via the People’s Voice Survey in 2022 and 2023.

First, survey respondents self-assessed their physical and mental health (the latter including “poor,” “fair,” “good,” “very good,” and “excellent”). Then, they quantified their overall confidence in the healthcare system, their own use of healthcare services, the typical quality of care received, and their ability to manage their own mental health (a metric called patient activation).

Mental healthcare receipt among people with poor mental health. Infographic displaying the weighted distribution of mental health status and care receipt. Each figure icon represents 2% of the population. Dark orange = respondents with poor/fair mental health who received mental healthcare in the past 12 months; light orange = those with poor/fair mental health who did not receive care; blue = those with good/very good/excellent mental health.

Image credit: Kruk ME, et al., 2026, PLOS Medicine, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

Across all countries, respondents reporting poor mental health were more likely to report chronic illness, poorer overall health, lower patient activation, worse care quality and lower confidence in the healthcare system. Between 0.9% (Lao PDR) and 52.4% (UK) of these respondents reported receiving mental health care in the last year. Respondents in Nigeria reported the best overall mental health (4.7% people reported the lowest proportion of “poor” or “fair” mental health (4.7%), while respondents in China had the highest proportion (39.6%).

The researchers hope these results can help the countries in question – and individual healthcare systems – better serve the needs of those with poor mental health. While this is a descriptive study, the researchers posit patient activation as a potential target for elevating overall health and wellness.

The authors acknowledge that big-picture data doesn’t describe individuals’ specific experiences within the healthcare system. They suggest comparison across similar health systems and tracking system performance over time to continuously improve health services.

The authors add, “What stands out from this study is that poor mental health doesn’t exist in isolation. People reporting poor mental health were nearly twice as likely to have a chronic illness and far less likely to feel empowered to manage their own health. Health systems need to stop treating mental health in a silo and recognise that these patients are showing up across all areas of care – and often with more complex needs.”

Kruk adds, “As a research consortium working across very different health systems, we expected to find variation, and we did, in treatment access. But the experience gap was remarkably consistent: people with poor mental health had worse care, more unmet needs, and less trust in the system, regardless of where they lived. Health systems globally need to rethink how they serve this growing group, not just whether they can reach them.”

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Categories : CancerTags :

Age, Sex, and Cancer Type Influence Risk of Subsequent Cancers Among Survivors

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Findings may have implications for long-term cancer survivorship surveillance

Researchers assess the risk of developing a subsequent primary cancer based on demographic factors and cancer characteristics. Tara Winstead, Pexels (CC0, https://creativecommons.org/publicdomain/zero/1.0/)

Risk of developing a subsequent primary cancer varied significantly by age at initial diagnosis, sex, and type of first cancer, according to a study by Oxana Palesh and Susan Hong and colleagues at Virginia Commonwealth University, U.S., published April 28th in the open-access journal PLOS Medicine.

Advances in cancer detection and treatment have led to a growing population of cancer survivors. In the U.S., the number of cancer survivors is expected to grow by 22% over the next decade – from 18 million in 2025 to more than 22 million by 2035. Survivors remain at higher risk for developing new primary cancers distinct from their original diagnosis. This risk may be influenced by factors such as older age, exposure to radiation and/or chemotherapy and ongoing lifestyle factors like smoking, obesity and poor diet. Understanding who is at greater risk and how this risk changes over time can help to inform prevention and monitoring strategies.

Using retrospective data from more than 3 million cancer survivors in the U.S., researchers examined how demographic factors and cancer characteristics correlate with subsequent cancer risk. Several factors were associated with developing a subsequent cancer, including older age at initial diagnosis and male sex. In addition, survivors of lung, bladder, and skin melanoma were at higher risk of developing new cancer.

These findings reinforce the importance of long‑term survivorship care and risk‑based monitoring. By identifying survivor groups at heightened risk, studies like this can help to inform tailored prevention strategies, surveillance guidelines, and survivorship care planning as the cancer survivor population continues to grow.

First author Hui Cheng adds, “By examining nearly five decades of national data, we found population-level shifts in subsequent primary cancer risk, with several survivor groups experiencing rising risks. These findings can help design more tailored surveillance and prevention strategies.”

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Categories : Cardiovascular DiseaseTags :

Genetic Study in Indians Finds New Pathways Involved in Cardiometabolic Disease

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Study of 3000 Punjabi Sikhs may yield new targets for treating Type 2 diabetes and other disorders

Photo by Sangharsh Lohakare on Unsplash

A study conducted in an Indian population has identified new molecular pathways that contribute to cardiovascular disease, which had not been reported previously in studies of Europeans. Dharambir Sanghera of the University of Oklahoma Health Sciences Center, US, led the new study, which was published April 23rd in the open access journal PLOS Medicine.

Worldwide, rates of cardiometabolic disease, which includes obesity, Type 2 diabetes and heart disease, are on the rise, and South Asian people living abroad appear to be especially susceptible. Previous studies have looked for genes that influence the levels of various breakdown products of lipids in the blood and their connection to different diseases, but most of this research has been conducted in people of European ancestry.

In the new study, researchers looked at how genetics influenced the levels of 516 lipid metabolites in the blood of 3000 Punjabi Sikh individuals, in an effort to better understand how these genetic pathways contribute to disease in different ethnic groups. They compared their findings to previous results from more than 1 million Europeans and 15 000 individuals with Indian ancestry. The team identified new genetic pathways that link specific lipid metabolites to disease. Notably, they confirmed that one metabolite, LPC O-16:0, which is known to be involved with immune cell signaling and inflammation, influences Type 2 diabetes risk. They also identified a genetic variant that may protect Indians from developing heart disease by modulating levels of the metabolite PC 38:4.

These findings offer new insights into the diverse molecular origins of cardiometabolic disease and provide potential pathways to be explored for designing innovative therapies. The researchers conclude that including more non-European participants in this type of research would help in identifying distinct disease subtypes linked to different genetic pathways. These advances would likely be beneficial in clinical practice by enabling more personalised therapies and preventive strategies for people from different backgrounds.

The authors add, “This study reveals new genetic pathways and lipid markers that contribute to type 2 diabetes and heart disease, specifically emphasising how immune system signaling affects metabolic health. By identifying unique genetic signatures in Asian Indians, the research advocates for ancestry-specific medical approaches to address chronic immuno-vascular conditions in cardiometabolic disease.”

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Categories : UncategorizedTags :

Neanderthals May Have Used Birch Tar for Its Anti-bacterial Properties

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Experiments confirm anti-biotic properties of birch bark extract

The bark of birch trees has been used to produce tar for more than 150 000 years. The centre photo shows birch bark tar condensed onto a rock that borders a hearth. When scraped off the rocks, the viscous tar can be used as both an adhesive and antibiotic.

Neanderthals probably used birch tar for multiple functions, including treating their wounds, according to a study published March 18, 2026 in the open-access journal PLOS One by a team of researchers led by Tjaark Siemssen of the University of Cologne, Germany, and the University of Oxford, UK.

Birch tar is commonly found at Neanderthal archaeological sites, and in some cases this tar is known to have been used as an adhesive to assemble tools. Recently, some researchers have raised the question of whether Neanderthals had multiple uses for this substance. For instance, Indigenous communities in northern Europe and Canada use birch tar to treat wounds, and there is growing evidence that Neanderthals also employed a variety of medical practices.

To investigate the medicinal potential of birch tar, Siemssen and colleagues extracted tar from modern birch tree bark, specifically targeting species known from Neanderthal sites. They used multiple extraction methods, including distillation of tar in a clay pit and condensation of tar against a stone surface, both of which would have been methods available to Neanderthals. When exposed to different strains of bacteria, all of the tar samples were found to be effective at hindering the growth of Staphylococcus bacteria known to cause wound infections.

These experiments not only support the efficacy of Indigenous medicinal practices, but also reinforce the possibility that Neanderthals used birch tar to treat wounds. The authors note that there are other potential uses of birch tar, such as insect repellent, as well as other plants to which Neanderthals had access. Further exploration of the multiple potential uses of these natural ingredients will enable a more thorough understanding of Neanderthal culture.

The authors add: “We found that the birch tar produced by Neanderthals and early humans had antibacterial properties. This has important implications for how Neanderthals may have mitigated disease burden during the last Ice Ages, and adds to a growing set of evidence on healthcare in these early human communities.”

“By bringing together research on indigenous pharmacology and experimental archaeology, we begin to understand the medicinal practices of our distant human ancestors and their closest cousins. Additionally, this study of ‘palaeopharmacology’ can contribute to the rediscovery of antibiotic remedies whilst we face an ever more pressing antimicrobial resistance crisis.”

“The messiness of birch tar production deserves a special mention. Every step of the production is a sensory experience in itself, and getting the tar off our hands after spending hours at the fire has been a challenge every time.”

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In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/4le9beh

Contact: Tjaark Siemssen, tjaark.siemssen@arch.ox.ac.uk

Image caption: The bark of birch trees has been used to produce tar for more than 150,000 years. The centre photo shows birch bark tar condensed onto a rock that borders a hearth. When scraped off the rocks, the viscous tar can be used as both an adhesive and antibiotic.

Image credit: Tjaark Siemssen, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

High-resolution image link: https://plos.io/4cteLHD

Citation: Siemssen T, Oludare A, Schemmel M, Puschmann J, Bierenstiel M (2026) Antibacterial properties of experimentally produced birch tar and its medicinal affordances in the Pleistocene. PLoS One 21(3): e0343618. https://doi.org/10.1371/journal.pone.0343618

Author countries: U.K., Canada, Belgium, Germany

Funding: Tjaark Siemssen is funded by the Boise Trust of the University of Oxford and the German Academic Scholarship Foundation (Studienstiftung). Aderonke Oludare was funded by Canadian Institutes of Health Research (CIHR) Project Grant 420598 awarded to Matthias Bierenstiel. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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