It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, August 01, 2023
Fascination of Science: 60 Encounters with Pioneering Researchers of Our Time
An intimate collection of portraits of internationally renowned scientists and Nobel Prize winners, paired with interviews and personal stories
IMAGE: COVER ART TO "FASCINATION OF SCIENCE"view more
CREDIT: THE MIT PRESS, 2023.
What makes a brilliant scientist? Who are the people behind the greatest discoveries of our time? Connecting art and science, photographer Herlinde Koelbl seeks the answers in this English translation of the German book Fascination of Science, an indelible collection of portraits of and interviews with sixty pioneering scientists of the twenty-first century. Koelbl's approach is intimate and accessible, and her highly personal interviews with her subjects reveal the forces (as well as the personal quirks) that motivate the scientists' work; for example, one wakes up at 3 am because her mind is calm then, another says his best ideas come to him in the shower. These glimpses into the scientists' lives and thinking add untold texture in this up-to-the-minute survey of the activities and progress that are currently taking place in the broad field of the natural sciences.
Koelbl's interview subjects include Nobel Prize winners Dan Shechtman, Frances Arnold, Carolyn Bertozzi, and cover scientific fields from astronomy, biochemistry, and quantum physics to stem-cell research and AI. Beautifully bringing together art, science, and the written word, Fascination of Science is an inspiring read that shows how creativity, obsession, persistence, and passion drive the pioneering researchers of our time.
Herlinde Koelbl is a German photographic artist, author, and documentary filmmaker. She has published more than a dozen photography books, including Jewish Portraits, Targets, and Angela MerkelPortraits 1991–2021. She has received numerous awards for her work, including the Dr. Erich Salomon Prize in 2001. You can learn more about her at www.herlindekoelbl.com.
“True to its title, this is a fascinating collection of interviews. Herlinde Koelbl's insightful questions and the candid responses of her subjects offer a matchless window into the personal histories and thinking of some of the world's most successful scientists."
-- John P. Holdren, Research Professor, Harvard University; President Obama's Science Advisor, January 2009 to January 2017
Contact: Head of UK and EU Publicity, Katie Lewis, The MIT Press, (lewisk@mit.edu)
Scientists vacuum animal DNA from air in a Danish forest
UNIVERSITY OF COPENHAGEN - THE FACULTY OF HEALTH AND MEDICAL SCIENCES
It is an early autumn morning. Three researchers from the Globe Institute at the University of Copenhagen venture into a Danish forest carrying plastic boxes with DNA air samplers. Wearing latex gloves and face masks, the researchers strap the samplers to tree trunks and attach air filters. They then turn on the power. A faint hum reveals that the collection of airborne particles is in progress.
During the following three days, the researchers returned to the forest to change the air filters several times.
“We saw relatively few animals in the short time we spent in the forest when we changed the air filters. A squirrel, the sound of a woodpecker, a pheasant squawking and a white-tailed eagle flying above us one day", says Postdoc Christina Lynggaard.
What the researchers did not notice in the forest, they saw when they sequenced the airborne DNA particles collected on the filters. In just three days of ‘vacuuming’ in an area of the forest roughly the size of a football field, the researchers found DNA traces from 64 animal species. Some of them were domestic animals such as cow, pig, sheep, chicken and dog and exotic pets such as parakeet and peacock. But in addition, the researchers recorded around 50 terrestrial wild animals.
The wild animals spanned small and large animals and animals with different lifestyles - red deer, roe deer, Eurasian badger, white-tailed eagle, red fox, different vole species, robin, Eurasian red squirrel, common toad, smooth newt, great crested newt, crane, great spotted woodpecker, nuthatch, grey heron, marsh tit, woodcock - and many more.
In a short time, the researchers found almost a quarter of the land-living animals previously recorded in and around the area.
“It's absolutely crazy! Although we have worked hard to optimise the method, we did not dare to hope for such good results. We didn't think we would succeed so well in the very first attempt in nature," says Associate Professor Kristine Bohmann.
Animal DNA in the air around us
The DNA that the researchers vacuumed from the air is the so-called environmental DNA.
“Animals secrete DNA into their surrounding environment all the time. It could be in the form of fragments of hair, feathers and skin cells. If they are airborne, we can vacuum them and use DNA analyses to find out which animals they came from", says Christina Lynggaard.
The new results follow the researchers' ground-breaking study from last year where they showed that animal DNA can be vacuumed from the air in a zoo. They used it to map the presence of many of the animals in Copenhagen ZOO.
"There is quite a difference between a zoo and nature," says Kristine Bohmann and continues: "In a zoo, the animals are present in large numbers in a relatively small area, while in nature they are much less concentrated. Therefore, we were unsure how well we could make the method work in nature. And that is where we have to get it to work if we want to use it to monitor biodiversity.”
A valuable tool
"We are in a biodiversity crisis, and tools are needed to understand how ecosystems change as a result of human impacts, to guide management strategies and to assess the risk of the spread of diseases in areas where animals can come into contact with people," says Christina Lynggaard.
The researchers' first results from vacuuming in nature show that airborne environmental DNA can be an effective method for mapping the presence of wild animals.
“As with all new methods, we have a lot of work ahead of us. But this study makes us hopeful. It demonstrates a sensitive method for mapping the presence of animals without having to see or disturb them," says Kristine Bohmann.
In the study, the researchers work with airborne environmental DNA in very small quantities. And because this is the first study to demonstrate the use of air filtration to detect the presence of a wide range of wildlife, the researchers went to great lengths to verify the findings.
"When we first detected DNA from peacocks, we were afraid that it might be a mistake. I therefore called around to find out if anyone who lived near the collection site had knowledge of peacocks in the area. Fortunately, they said that they had sometimes come across a peacock when they went for a walk", says Kristine Bohmann, who in this way was able to verify the otherwise somewhat unusual DNA find.
The new research is primarily supported by the VILLUM Foundation in their research program "VILLUM Experiment", which supports research projects out of the ordinary that challenge the norm and have the potential to change fundamentally the way we approach important topics.
The research is also supported by the VILLUM Foundation with a grant to Christina Lynggaard in their research program 'VILLUM International Postdoc', which supports the advancement of talented postdoc women in their research careers.
The research is also supported by the Carlsberg Foundation with a grant to Kristine Bohmann in their research programme 'Semper Ardens: Accelerate'. This grant has enabled her to establish a research group focused on developing methods to use airborne environmental DNA to monitor birds and mammals.
Airborne environmental DNA captures terrestrial vertebrate diversity in nature
ARTICLE PUBLICATION DATE
27-Jul-2023
COI STATEMENT
M.S.J. is Chief Science Officer at DevLabs. The current study is not of direct commercial value to DevLabs. The remaining authors declare that they have no competing interests.
Cities no place for Australian eagles but smaller raptors are adapting
IMAGE: FLINDERS UNIVERSITY PHD CANDIDATE TAYLOR HEADLAND IS STUDYING THE BEHAVIOUR OF NANKEEN KESTRELS IN URBAN ENVIRONMENTS.view more
CREDIT: COURTESY: PETRA SUMASGUTNER (UNIVERSITY OF VIENNA)
Increasing urbanisation is reducing biodiversity with cities proving harsh places for many of Australia’s native wildlife to live – not least magnificent birds of prey which face lack of habitat, high buildings and disturbance by car noise and night lights.
An international team of experts, led by Flinders University’s BirdLab and the University of Vienna, has evaluated the adaptability and ‘urban tolerance’ of 24 Australian raptor species and found 13 of the smaller birds of prey such as kites and falcons showing higher tolerance for living in urban areas than 11 of the larger bodied species.
The species with the highest tolerance to urbanisation were the Eastern Barn Owl, Brahminy Kite and the Australian Hobby (Falco longipennis), while the Brown Falcon (Falco berigora) and the Wedge-tailed Eagle (Aquila audax) were the least tolerant raptor species to urban areas.
Around the world, urban tolerance is generally higher in wildlife which have flexible behaviour to learn to live in closer proximity to humans, have high fertility and strong dispersal ability over various landscapes such as urban green spaces, parks, cemeteries or golf courses, say experts from South Australia, Europe, South Africa and the US in the new article in Nature Scientific Reports.
The analysis of community science data sourced from eBird looked at raptors’ body mass, nest and habitat types, feeding and migratory status to assess their tolerance, says lead author University of Vienna raptor conservation researcher Dr Petra Sumasgutner. The worldwide decline in predator populations is contributing substantially to the biodiversity crisis.
“As we see extensive cascading effects on ecosystems caused by human-dominated landscapes, we can find examples of predators which stay or return to ecosystems creating a buffer against biological invasion and disease transmission,” she says.
“While some species of raptors are able to take advantage of human-dominated landscapes and urban areas, we are seeing a worrying population decline in many parts of the world.”
Of more than 500 raptor species, 52% are in decline and 19% are currently classified as threatened with extinction.
The study of Australian raptors was inspired by in-depth studies by Flinders University PhD Taylor Headland on the small-bodied Australian falcon – the Nankeen kestrel – which has shown adaptive techniques in both human-modified and natural landscapes alike.
“As raptors are vital for ecosystem functioning, prioritising feeding and breeding habitat for urban-tolerated raptor species is essential to enable biodiverse urban landscapes,” says co-author Mr Headland, from the BirdLab research group at Flnders University’s College of Science and Engineering.
“While we see evidence of small Australian raptors persisting in urban environments, conservation management initiatives focusing on habitat protection and restoration of wilderness areas need also to focus on the needs of larger-bodied raptor species given the rise in urban expansion and their avoidance of city zones.
“We are concerned for the raptors of Australia and the Southern Hemisphere which are far less studied than those in the Northern Hemisphere so resources such as eBird life are invaluable.”
Using 276,674 species observations of 24 raptors, the Whistling Kite (Haliastur sphenurus) was detected the most of any raptor in the study, amassing 45,787 observations, while the Eastern Barn Owl (Tyto alba) was observed the fewest times.
The raptors observed in the area with the highest median radiance were the Brown Goshawk (Accipiter fasciatus) and Southern Boobook (Ninox boobook) in Docklands Park, in central Melbourne, Victoria.
A Whistling Kite was sighted in the area with the lowest median radiance, which was at Lagoon Island, Lake Argyle, in north-eastern Western Australia.
Since the Cornell Lab of Ornithology and US Audibon Society launched eBird more than a decade ago, more than 90 million checklists and 1.2 billion observations of birds have been submitted – making it one of the most successful community or citizen science projects to date.
Read the article – Smaller Australian raptors have greater urban tolerance (2023) by T Headland, D Colombelli-Négrel, CT Callaghan, SC Sumasgutner, S Kleindorfer and P Sumasgutner – published in Scientific Reports DOI 10.10 38/s41598-023-38493-z.
Coauthor Professor Sonia Kleindorfer examines a native Australian Nankeen kestrel.
CREDIT
Courtesy: Petra Sumasgutner (University of Vienna)
CAPTION
The Wedge-tailed Eagle (Aquila audax) is among the least tolerant raptor species to urban areas
The dry summer of 2018 hit Swedish forests hard - and hardest affected were the managed secondary forests. This according to a new study from Lund University in Sweden.
Northern boreal forest ecosystems are predicted to experience more frequent summer droughts in the future. The majority of Swedish forest are secondary forests that are managed commercial forests with little diversity in species and structure. Only a small part is made up of primary forests that have experienced limited direct human impact.
So far, it has not been known how primary forests and managed secondary forests react to drought. In a new study published in the scientific journal Environmental Research Letters, a team of researchers led from Lund, analysed how the drought of 2018 affected the forest types.
“We used a unique map of primary forests in Sweden and investigated whether there might be any difference in how these forests and neighbouring secondary forests were affected by the drought in 2018. The results showed that secondary forests in Sweden were more affected by the drought than primary forests were,” says Anders Ahlström, researcher in physical geography at Lund University.
In the study, researchers used satellite images and a map detailing more than 300 primary forests in Sweden. By analysing a high-resolution vegetation index over these and the buffer zones surrounding the primary forests, which represent secondary forests with a similar environment and drought situation in summer 2018, the research team were able to gain a picture of how the dry summer hit the different forest types.
“That primary forests were less affected by drought leads to a number of interesting follow-up questions about what causes this difference. It could be the trees’ generally greater age and size that perhaps leads to deeper roots and more structural diversity. Or it could be that there is more water in these ecosystems, perhaps because they haven’t been ditched. Right now though, we have no idea what makes primary forests more stable during drought,” says Julika Wolf, former physical geography researcher, now a consultant on cartography and spatial analysis.
Primary forests are rare in Sweden and in Europe. They represent the most untouched forests we have left, and they inform us of how nature looks and how it functions without major direct human impact. The forests, therefore, are especially important in understanding how environmental changes and human land use affect ecosystems and their processes.
“This study is a good example of how we can use these primary forests in our research. In this case, we see that they are more stable during drought when compared with secondary forests that have been exposed to change such as felling, planting, ground preparation and ditching.” concludes Anders Ahlström.
Canopy responses of Swedish primary and secondary forests to the 2018 drought
Study proposes refinement of models to project ecosystem services in montane forests
Modeling projections depend on the installation of networks specific to these areas in Brazil and the Andes, where the available data falls far short of what is needed.
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO
IMAGE: MODELING PROJECTIONS DEPEND ON THE INSTALLATION OF NETWORKS SPECIFIC TO THESE AREAS IN BRAZIL AND THE ANDES, WHERE THE AVAILABLE DATA FALLS FAR SHORT OF WHAT IS NEEDEDview more
CREDIT: LASZLO KAROLY NAGY
Tropical mountain ecosystems, including montane forests, are relatively little studied, yet they are home to significant biodiversity and provide important ecosystem services, such as water supply and participation in regulation of temperature and regional and global climate. The data available on mountain vegetation and its dynamics falls far short of what is needed to simulate with confidence its interaction with the atmosphere in response to climate change.
A new study published in the journal Plant Ecology & Diversity by a group of scientists affiliated with universities in Brazil and several other South American countries, as well as the United Kingdom, casts light on these questions. An effective way to bridge this gap, the authors of the article argue, would be to create “a transdisciplinary network” capable of studying the natural dynamics of mountain ecosystems and their responses to global change drivers locally, regionally and across the continent, within the framework of a socio-ecological system.
“The results of our research show that very little information of the kind needed to model mountain clusters in South America is available. We need more specific data to do this modeling, especially if we want to include socio-ecological diversity. We advocate the creation of a network of sites representing the heterogeneity of social and ecological conditions in montain ecosystems with the aim of quantifying the hitherto neglected role of these ecosystems in carbon and water cycling, as well as other ecosystem services,” Laszlo Karoly Nagy, first author of the article, told.
Nagy is a professor at the State University of Campinas (UNICAMP) in São Paulo state, Brazil, and coordinator of the Long-Term Ecological Research Project in Campos do Jordão State Park (PELD-PECJ), also in São Paulo state. His contribution to the study was supported by FAPESP.
The last author was Stephen Sitch, Chair in Climate Change at the University of Exeter, whose contribution was supported by the Natural Environment Research Council (NERC), part of UK Research & Innovation (UKRI), the United Kingdom’s science and research funding agency.
Tropical montane ecosystems in South America
Tropical forests in mountainous areas more than 1,000 meters above sea level vary from wet, like Serra do Mar in Brazil, for example, or parts of the Andes adjacent to the western Amazon Basin, to seasonally dry, like the Atlantic Rainforest biome or the Andean inter-ridge valleys.
Mountain vegetation comprises both forest and non-forest. Tree growth is limited at high altitudes and low temperatures, but climate change will alter the structure and functioning of these ecosystems. The Andes has many montane forest areas, for example, but current rates of warming there are three times higher than in other parts of South America, and temperatures in the region are expected to rise as much as 6 °C by the end of this century.
South America’s mountains also have large non-forest areas where land use has changed to agriculture and pasture. In this context, the subtropical and tropical mountains of South America are a high priority for projecting the impact of future climate on the structure and functioning of these ecosystems in terms of climate feedback and potential use of ecosystem services.
In the study, which was based on a workshop held in Campinas, the researchers analyzed a network of mountain ecosystem sites in South America, cataloging and synthesizing existing knowledge for use in future modeling of these sites’ contribution to regional and global carbon/water cycles.
“Selection of the areas has to be stratified on the basis of climate and biogeography, taking into consideration the historical and cultural context for land use,” Nagy said. “All this shows the diversity of situations to be analyzed in socio-ecological terms so that the available knowledge can be synthesized and a pathway found for the construction of a wide-ranging project.”
Methodology
The study covered eight sites in the Andes and Southeast Brazil: the Venezuelan, Colombian and west Ecuadorean Andes; the Amazon-Andes transect in Peru; the mountains of northwest Argentina; Cape Horn in Chile; and Serra da Mantiqueira and Serra do Cipó in Brazil.
Only two of these (one in Venezuela and the other in Brazil) had climate, ecological and ecophysiological data that could be used as parameters for dynamic global vegetation models (DGVMs), computer programs that simulate shifts in vegetation and the associated biological and hydrological cycles in response to climate change for decades ahead.
Tree biomass data was available for six sites. The scientists performed a preliminary assessment using a DGVM known as JULES (Joint UK Land Environment Simulator) to look for gaps in available data and their impact on model parameterization and calibration. This analysis identified a temperature-related decrease in montane forest net primary production, respiration, and allocation to above-ground biomass, as well as an increase in soil carbon stocks with elevation.
One of the difficulties for researchers on these regions is obtaining data to identify the transition between montane forest and non-arboreal alpine vegetation. “If we combine modelers and field researchers who know the forest, we can decide what works for each participant, identify the peculiarities, and see how they can talk to each other. It’s most important for the two communities to interact so that the results produced by modeling can be checked against empirical data,” Nagy said.
Next steps will include continuing the development of models with Ibero-American colleagues, including Brazilians, and three European groups of modelers. All these groups work at different scales, including the global scale adjusted for mountains and landscape, which can encompass land use.
“Mountain characteristics require a specific approach,” he said. “For example, you should analyze how tree growth is limited in terms of plant tissue production versus limitation by photosynthesis.”
Right now, he added, the work entails bringing together the various actors, including a network of socio-ecological observatories for the Andes (ROSA), under construction, and definition of the sites to be studied in the next stage of the project.
About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.
South American mountain ecosystems and global change – a case study for integrating theory and field observations for land surface modelling and ecosystem management
Boston - July 27, 2023 - Mangos are one of the most popular fruits1 in the world, grown in more than 100 countries2 globally and consumed by an extremely diverse population. Now, two new studies funded by the National Mango Board and presented as posters during the American Society for Nutrition’s Annual Conference (Nutrition 2023) show mangos may play a role in risk reductions for vascular issues while helping to improve antioxidant levels among relatively healthy adult men and women who are overweight or obese.
“Mangos contribute a variety of nutrients, phytochemicals and bioactive compounds to the diet—including 50 percent of the daily value (DV) for vitamin C, 15 percent of the DV for folate and 15 percent of the DV for copper, and mangoes are also a predominant source of the bioactive compound mangiferin,” says Mee Young Hong, Ph.D., the primary investigator for both studies and professor at the School of Exercise and Nutritional Sciences in the College of Health and Human Services at San Diego State University. “It’s likely the unique matrix of vitamins and bioactive compounds synergistically working together that resulted in our findings,” says Young Hong.
Both crossover interventions followed the same 27 overweight or obese participants (16 males, 11 females; BMI 31.8 +/- 4.1 kg/m2) that were between the ages of 18-55 for 28 weeks. The participants were separated into two groups and instructed to eat either a 100-calorie snack of mangos (1 cup) or a 100-calorie snack of low-fat cookies for 12 weeks, as part of their normal lifestyle and eating patterns. Following the first 12 weeks, participants took a 4-week washout break then switched groups and consumed the alternate snack for another 12 weeks. During each 12-week period, participants provided fasting blood samples three times: at baseline, week 4 and week 12.
When the mango snack was eaten versus the low-fat cookie snack, following the12-week intervention, findings from the first study show significant health-positive changes to two markers of oxidative stress, reduced vascular cell adhesion molecule-1 (VCAM-1) and increased superoxide dismutase (SOD). Findings from the second study show a significant increase of glutathione peroxidase (GPX), a powerful antioxidant enzyme. Other biomarker and biochemical analyses performed across the two studies, which tested additional vascular, inflammatory, and immune risk factors and mediators, did not yield significant results.
“SOD and VCAM-1 play opposite roles as risk factors for vascular issues,” says Young Hong. “While the SOD enzyme reduces risk by breaking down charged oxygen molecules called superoxide radicals,3 which are toxic, the VCAM-1 gene causes cells to stick together along the vascular lining, leading to increased risk for issues.4 To achieve good vascular health, we want to see these two compounds move in opposite directions—SOD up and VCAM-1 down—which is what happened in the study. Additionally, GPX acts by converting hydrogen peroxide to water in the body, thus reducing the harmful oxidative effects of hydrogen peroxide,”5 says Young Hong.
“The totality of findings across both studies continues to add to a growing body of fresh mango research and can help to further advance the scientific understanding of the role mangos can play in helping all Americans achieve their health and wellness goals,” says Leonardo Ortega, Director of Research, National Mango Board.
“Vascular diseases include strokes, which are the third leading cause of death in the United States. Helping Americans find food-first solutions for reducing risks, like including more fruits, such as mangos, in the diet, is critical to reverse these trends and improve public health,” says Young Hong.
With only 70 calories and over 20 different vitamins and minerals, a 3/4-cup serving of mango is nutrient-dense, making it a superfood. Because mangos are widely consumed in cultures around the world including the United States, research into their health benefits contributes to a better understanding of their place in a healthy diet.
Mitra, S.K. (2016). Mango production in the world – present situation and future prospect. Acta Hortic. 1111, 287-296 DOI: 10.17660/ActaHortic.2016.1111.41 https://doi.org/10.17660/ActaHortic.2016.1111.41
Lubos E, Loscalzo J, Handy DE. Glutathione peroxidase-1 in health and disease: from molecular mechanisms to therapeutic opportunities. Antioxid Redox Signal. 2011 Oct 1;15(7):1957-97. doi: 10.1089/ars.2010.3586. Epub 2011 Apr 10. PMID: 21087145; PMCID: PMC3159114.
Drinking kombucha may reduce blood sugar levels in people with type-two diabetes
Small pilot study suggests larger trials warranted to confirm potential benefit of fermented tea
WASHINGTON — People with type-II diabetes who drank the fermented tea drink kombucha for four weeks had lower fasting blood glucose levels compared to when they consumed a similar-tasting placebo beverage, according to results from a clinical trial conducted by researchers at Georgetown University's School of Health, the University of Nebraska-Lincoln and MedStar Health. This finding, from a pilot 12-person feasibility trial, points to the potential for a dietary intervention that could help lower blood sugar levels in people with diabetes and also establishes the basis for a larger trial to confirm and expand upon these results.
This finding was reported in Frontiers in Nutrition on August 1, 2023.
Kombucha is a tea fermented with bacteria and yeasts and was consumed as early as 200 B.C. in China, but it did not become popular in the U.S. until the 1990s. Its popularity has been bolstered by anecdotal claims of improved immunity and energy and reductions in food cravings and inflammation, but proof of these benefits has been limited.
“Some laboratory and rodent studies of kombucha have shown promise and one small study in people without diabetes showed kombucha lowered blood sugar, but to our knowledge this is the first clinical trial examining effects of kombucha in people with diabetes,” says study author Dan Merenstein, M.D., professor of Human Sciences in Georgetown’s School of Health and professor of family medicine at Georgetown University School of Medicine. “A lot more research needs to be done but this is very promising.”
Merenstein continued, “A strength of our trial was that we didn't tell people what to eat because we used a crossover design that limited the effects of any variability in a person’s diet.”
The crossover design had one group of people drinking about eight ounces of kombucha or placebo beverage daily for four weeks and then after a two-month period to ‘wash out’ the biological effects of the beverages, the kombucha and placebo were swapped between groups with another four weeks of drinking the beverages. Neither group was told which drink they were receiving at the time.
Kombucha appeared to lower average fasting blood glucose levels after four weeks from 164 to 116 milligrams per deciliter while the difference after four weeks with the placebo was not statistically significant. Guidelines from the American Diabetes Association recommended blood sugar levels before meals should be between 70 to 130 milligrams per deciliter.
The researchers also looked at the makeup of fermenting micro-organisms in kombucha to determine which ingredients might be the most active. They found that the beverage was mainly comprised of lactic acid bacteria, acetic acid bacteria, and a form of yeast called Dekkera, with each microbe present in about equal measure; the finding was confirmed with RNA gene sequencing.
The kombucha used in this study was produced by Craft Kombucha, a commercial manufacturer in the Washington, DC, area. It has been re-branded as Brindle Boxer Kombucha.
“Different studies of different brands of kombucha by different manufacturers reveal slightly different microbial mixtures and abundances,” says Robert Hutkins, Ph.D., University of Nebraska-Lincoln and the study’s senior author. “However, the major bacteria and yeasts are highly reproducible and likely to be functionally similar between brands and batches, which was reassuring for our trial.”
“An estimated 96 million Americans have pre-diabetes -- and diabetes itself is the eighth leading cause of death in the U.S. as well as being a major risk factor for heart disease, stroke and kidney failure,” says Chagai Mendelson, M.D., lead author who was working in Merenstein’s lab at Georgetown while completing his residency at MedStar Health. “We were able to provide preliminary evidence that a common drink could have an effect on diabetes. We hope that a much larger trial, using the lessons we learned in this trial, could be undertaken to give a more definitive answer to the effectiveness of kombucha in reducing blood glucose levels, and hence prevent or help treat type-II diabetes.”
###
Additional study authors at Georgetown University are Sabrina Sparkes, a student in the School of Health, Varun Sharma and Sameer Desale. In addition to Hutkins, Chloe Christensen, Jennifer M. Auchtung, Car Reen Kok and Heather E. Hallen-Adams are at the University of Nebraska-Lincoln.
The authors wish to express their gratitude to Tanya Maynigo, founder of Craft Kombucha for providing the kombucha and placebo kombucha for this study. She teaches kombucha classes in Washington, DC, and this year is launching a new brand of her favorite drink called Brindle Boxer Kombucha.
The study received no external funding.
Hutkins is a co-founder of Synbiotic Health. Auchtung has a financial interest in Synbiotic Health. Merenstein is president of the International Scientific Association for Probiotics and Prebiotics board, a non-paid position. All other authors have no competing interests to declare. All kombucha and placebo drinks were donated by Craft Kombucha. Craft Kombucha did not have any access to data reported in this study. No author has any financial ties with Craft Kombucha.
AboutGeorgetown University Medical Center As a top academic health and science center, Georgetown University Medical Center provides, in a synergistic fashion, excellence in education — training physicians, nurses, health administrators and other health professionals, as well as biomedical scientists — and cutting-edge interdisciplinary research collaboration, enhancing our basic science and translational biomedical research capacity in order to improve human health. Patient care, clinical research and education is conducted with our academic health system partner, MedStar Health. GUMC’s mission is carried out with a strong emphasis on social justice and a dedication to the Catholic, Jesuit principle of cura personalis -- or “care of the whole person.” GUMC comprises the School of Medicine, the School of Nursing, School of Health, Biomedical Graduate Education, and Georgetown Lombardi Comprehensive Cancer Center. Designated by the Carnegie Foundation as a doctoral university with "very high research activity,” Georgetown is home to a Clinical and Translational Science Award from the National Institutes of Health, and a Comprehensive Cancer Center designation from the National Cancer Institute. Connect with GUMC on Facebook (Facebook.com/GUMCUpdate) and on Twitter (@gumedcenter).
JOURNAL
Frontiers in Nutrition
METHOD OF RESEARCH
Randomized controlled/clinical trial
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Kombucha Tea as an Anti-Hyperglycemic Agent in Humans with Diabetes -A Randomized Controlled Pilot Investigation
ARTICLE PUBLICATION DATE
1-Aug-2023
COI STATEMENT
Hutkins is a co-founder of Synbiotic Health. Auchtung has a financial interest in Synbiotic Health. Merenstein is president of the International Scientific Association for Probiotics and Prebiotics board, a non-paid position. All other authors have no competing interests to declare. All kombucha and placebo drinks were donated by Craft Kombucha. Craft Kombucha did not have any access to data reported in this study. No author has any financial ties with Craft Kombucha.
