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Jan Claesen

@claesengroup.bsky.social

Associate Professor at Lerner Research Institute, Cleveland Clinic. Lover of bacteria in isolation and in communities. Dissecting the human microbiome on a molecular level. πŸ‡§πŸ‡ͺπŸ‡ΊπŸ‡Έ Father of two. Views are my own. https://claesengroup.org/

4,241 Followers  |  1,598 Following  |  208 Posts  |  Joined: 06.09.2023
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Posts by Jan Claesen (@claesengroup.bsky.social)

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Screening, sorting, and the feedback cycles that imperil peer review The process of peer review is vital to contemporary science, but is also under enormous strain. This study uses mathematical models to dissect the threats to the long-term viability of peer review, su...

1. Kevin Gross and I have a new paper out today PLOS Biology.

We used economic models based around screening games and the market for unpaid labor to highlight a meltdown cycle threatening peer review.

24.02.2026 20:54 β€” πŸ‘ 323    πŸ” 131    πŸ’¬ 8    πŸ“Œ 17
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The MIBiG 5.0 Annotathon is coming soon, and registration is now open!

🧬 Does your research involve biosynthetic gene clusters? Do you love natural product biosynthesis? Do you have an interest in rare & exotic enzymes? We can use your help & expertise.

Register here πŸ‘‰ forms.gle/C1cWcLHtrjT2...

20.02.2026 04:06 β€” πŸ‘ 27    πŸ” 20    πŸ’¬ 1    πŸ“Œ 5

A fabulous undergraduate researcher I mentor is graduating this spring and is looking for a job as a lab technician! She's interested in bacterial pathogenesis and is planning to go to grad school after getting more research experience. Please let me know if you or anyone you know is hiring!

20.02.2026 21:03 β€” πŸ‘ 8    πŸ” 5    πŸ’¬ 1    πŸ“Œ 0

Congrats! πŸŽ‰

20.02.2026 12:47 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Congrats Marnix!

12.02.2026 14:21 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
A figure from the paper that provides an overview of available culture-dependent and culture-independent approaches for characterizing the human gut virome. Both culture-dependent and culture-independent approaches should be used to study the gut virome. At the bench, many protocols have been adapted to enrich viruses in a sample and isolate them using a sensitive host. Once a virus is isolated, various assays can be used to characterize how the virus interacts with its bacterial host. On the command line, viral genomes can be predicted and viral taxonomy can be identified within a sample. Once procured, multiple tools can be used to annotate viral genomes for predicted gene content and viral lifestyle and predict bacterial host taxonomy.

A figure from the paper that provides an overview of available culture-dependent and culture-independent approaches for characterizing the human gut virome. Both culture-dependent and culture-independent approaches should be used to study the gut virome. At the bench, many protocols have been adapted to enrich viruses in a sample and isolate them using a sensitive host. Once a virus is isolated, various assays can be used to characterize how the virus interacts with its bacterial host. On the command line, viral genomes can be predicted and viral taxonomy can be identified within a sample. Once procured, multiple tools can be used to annotate viral genomes for predicted gene content and viral lifestyle and predict bacterial host taxonomy.

It's increasingly clear that commensal viruses play important roles in human health, but how do you study them?

Our review "Tools and approaches to study the human gut virome: from the bench to bioinformatics" is out today in mSystems! journals.asm.org/doi/10.1128/...

@haleybiont.bsky.social

04.02.2026 16:05 β€” πŸ‘ 23    πŸ” 11    πŸ’¬ 3    πŸ“Œ 0
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Our new paper, where we use metabolic modeling to show Fusobacterium grows faster in colorectal tumor vs normal tissue microenvironments, and use computational + experimental approach to find specific metabolic pathways driving host-microbiome interactions in cancer

www.biorxiv.org/content/10.6...

04.02.2026 14:17 β€” πŸ‘ 15    πŸ” 5    πŸ’¬ 2    πŸ“Œ 0
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Exclusive: key NIH review panels due to lose all members by the end of 2026 Thirteen of the agency’s advisory councils, which must review grant applications before funding is awarded, are on track to have no voting members.

🚨 New from me: Grant review at more than half of NIH's institutes could be frozen by the end of the year.

That's because crucial NIH grant-review panels are slated to be empty at those institutes by Jan 2027.

A wonky bureaucratic problem with big implications.

A short 🧡

22.01.2026 19:46 β€” πŸ‘ 321    πŸ” 259    πŸ’¬ 2    πŸ“Œ 35
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A free, open-access library of high-quality organism illustrations for science communication We create vector graphics of model organisms and emerging biological research organisms to enhance our publications. We’re sharing these editable graphics under a CC0 license for other scientists to...

A free, open-access library of high-quality organism illustrations for science communication

29.12.2025 18:03 β€” πŸ‘ 269    πŸ” 134    πŸ’¬ 1    πŸ“Œ 4
A table showing profit margins of major publishers. A snippet of text related to this table is below.

1. The four-fold drain
1.1 Money
Currently, academic publishing is dominated by profit-oriented, multinational companies for
whom scientific knowledge is a commodity to be sold back to the academic community who
created it. The dominant four are Elsevier, Springer Nature, Wiley and Taylor & Francis,
which collectively generated over US$7.1 billion in revenue from journal publishing in 2024
alone, and over US$12 billion in profits between 2019 and 2024 (Table 1A). Their profit
margins have always been over 30% in the last five years, and for the largest publisher
(Elsevier) always over 37%.
Against many comparators, across many sectors, scientific publishing is one of the most
consistently profitable industries (Table S1). These financial arrangements make a substantial
difference to science budgets. In 2024, 46% of Elsevier revenues and 53% of Taylor &
Francis revenues were generated in North America, meaning that North American
researchers were charged over US$2.27 billion by just two for-profit publishers. The
Canadian research councils and the US National Science Foundation were allocated US$9.3
billion in that year.

A table showing profit margins of major publishers. A snippet of text related to this table is below. 1. The four-fold drain 1.1 Money Currently, academic publishing is dominated by profit-oriented, multinational companies for whom scientific knowledge is a commodity to be sold back to the academic community who created it. The dominant four are Elsevier, Springer Nature, Wiley and Taylor & Francis, which collectively generated over US$7.1 billion in revenue from journal publishing in 2024 alone, and over US$12 billion in profits between 2019 and 2024 (Table 1A). Their profit margins have always been over 30% in the last five years, and for the largest publisher (Elsevier) always over 37%. Against many comparators, across many sectors, scientific publishing is one of the most consistently profitable industries (Table S1). These financial arrangements make a substantial difference to science budgets. In 2024, 46% of Elsevier revenues and 53% of Taylor & Francis revenues were generated in North America, meaning that North American researchers were charged over US$2.27 billion by just two for-profit publishers. The Canadian research councils and the US National Science Foundation were allocated US$9.3 billion in that year.

A figure detailing the drain on researcher time.

1. The four-fold drain

1.2 Time
The number of papers published each year is growing faster than the scientific workforce,
with the number of papers per researcher almost doubling between 1996 and 2022 (Figure
1A). This reflects the fact that publishers’ commercial desire to publish (sell) more material
has aligned well with the competitive prestige culture in which publications help secure jobs,
grants, promotions, and awards. To the extent that this growth is driven by a pressure for
profit, rather than scholarly imperatives, it distorts the way researchers spend their time.
The publishing system depends on unpaid reviewer labour, estimated to be over 130 million
unpaid hours annually in 2020 alone (9). Researchers have complained about the demands of
peer-review for decades, but the scale of the problem is now worse, with editors reporting
widespread difficulties recruiting reviewers. The growth in publications involves not only the
authors’ time, but that of academic editors and reviewers who are dealing with so many
review demands.
Even more seriously, the imperative to produce ever more articles reshapes the nature of
scientific inquiry. Evidence across multiple fields shows that more papers result in
β€˜ossification’, not new ideas (10). It may seem paradoxical that more papers can slow
progress until one considers how it affects researchers’ time. While rewards remain tied to
volume, prestige, and impact of publications, researchers will be nudged away from riskier,
local, interdisciplinary, and long-term work. The result is a treadmill of constant activity with
limited progress whereas core scholarly practices – such as reading, reflecting and engaging
with others’ contributions – is de-prioritized. What looks like productivity often masks
intellectual exhaustion built on a demoralizing, narrowing scientific vision.

A figure detailing the drain on researcher time. 1. The four-fold drain 1.2 Time The number of papers published each year is growing faster than the scientific workforce, with the number of papers per researcher almost doubling between 1996 and 2022 (Figure 1A). This reflects the fact that publishers’ commercial desire to publish (sell) more material has aligned well with the competitive prestige culture in which publications help secure jobs, grants, promotions, and awards. To the extent that this growth is driven by a pressure for profit, rather than scholarly imperatives, it distorts the way researchers spend their time. The publishing system depends on unpaid reviewer labour, estimated to be over 130 million unpaid hours annually in 2020 alone (9). Researchers have complained about the demands of peer-review for decades, but the scale of the problem is now worse, with editors reporting widespread difficulties recruiting reviewers. The growth in publications involves not only the authors’ time, but that of academic editors and reviewers who are dealing with so many review demands. Even more seriously, the imperative to produce ever more articles reshapes the nature of scientific inquiry. Evidence across multiple fields shows that more papers result in β€˜ossification’, not new ideas (10). It may seem paradoxical that more papers can slow progress until one considers how it affects researchers’ time. While rewards remain tied to volume, prestige, and impact of publications, researchers will be nudged away from riskier, local, interdisciplinary, and long-term work. The result is a treadmill of constant activity with limited progress whereas core scholarly practices – such as reading, reflecting and engaging with others’ contributions – is de-prioritized. What looks like productivity often masks intellectual exhaustion built on a demoralizing, narrowing scientific vision.

A table of profit margins across industries. The section of text related to this table is below:

1. The four-fold drain
1.1 Money
Currently, academic publishing is dominated by profit-oriented, multinational companies for
whom scientific knowledge is a commodity to be sold back to the academic community who
created it. The dominant four are Elsevier, Springer Nature, Wiley and Taylor & Francis,
which collectively generated over US$7.1 billion in revenue from journal publishing in 2024
alone, and over US$12 billion in profits between 2019 and 2024 (Table 1A). Their profit
margins have always been over 30% in the last five years, and for the largest publisher
(Elsevier) always over 37%.
Against many comparators, across many sectors, scientific publishing is one of the most
consistently profitable industries (Table S1). These financial arrangements make a substantial
difference to science budgets. In 2024, 46% of Elsevier revenues and 53% of Taylor &
Francis revenues were generated in North America, meaning that North American
researchers were charged over US$2.27 billion by just two for-profit publishers. The
Canadian research councils and the US National Science Foundation were allocated US$9.3
billion in that year.

A table of profit margins across industries. The section of text related to this table is below: 1. The four-fold drain 1.1 Money Currently, academic publishing is dominated by profit-oriented, multinational companies for whom scientific knowledge is a commodity to be sold back to the academic community who created it. The dominant four are Elsevier, Springer Nature, Wiley and Taylor & Francis, which collectively generated over US$7.1 billion in revenue from journal publishing in 2024 alone, and over US$12 billion in profits between 2019 and 2024 (Table 1A). Their profit margins have always been over 30% in the last five years, and for the largest publisher (Elsevier) always over 37%. Against many comparators, across many sectors, scientific publishing is one of the most consistently profitable industries (Table S1). These financial arrangements make a substantial difference to science budgets. In 2024, 46% of Elsevier revenues and 53% of Taylor & Francis revenues were generated in North America, meaning that North American researchers were charged over US$2.27 billion by just two for-profit publishers. The Canadian research councils and the US National Science Foundation were allocated US$9.3 billion in that year.

The costs of inaction are plain: wasted public funds, lost researcher time, compromised
scientific integrity and eroded public trust. Today, the system rewards commercial publishers
first, and science second. Without bold action from the funders we risk continuing to pour
resources into a system that prioritizes profit over the advancement of scientific knowledge.

The costs of inaction are plain: wasted public funds, lost researcher time, compromised scientific integrity and eroded public trust. Today, the system rewards commercial publishers first, and science second. Without bold action from the funders we risk continuing to pour resources into a system that prioritizes profit over the advancement of scientific knowledge.

We wrote the Strain on scientific publishing to highlight the problems of time & trust. With a fantastic group of co-authors, we present The Drain of Scientific Publishing:

a 🧡 1/n

Drain: arxiv.org/abs/2511.04820
Strain: direct.mit.edu/qss/article/...
Oligopoly: direct.mit.edu/qss/article/...

11.11.2025 11:52 β€” πŸ‘ 641    πŸ” 453    πŸ’¬ 8    πŸ“Œ 66

Ruin a book with a car:

Ford of the rings

25.09.2025 11:43 β€” πŸ‘ 3    πŸ” 0    πŸ’¬ 0    πŸ“Œ 1

Music FACT: Placebo were originally a Cure tribute band

19.09.2025 08:15 β€” πŸ‘ 173    πŸ” 46    πŸ’¬ 9    πŸ“Œ 0

She's a real hero!
πŸ’ͺπŸ‘‡

08.09.2025 18:20 β€” πŸ‘ 3    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
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✨ Exciting News ✨I am thrilled to share that I have accepted a position as an Assistant Professor in the Department of Infectious Diseases and Microbiology (IDM), at the University of Pittsburgh School of Public Health!

03.09.2025 15:48 β€” πŸ‘ 76    πŸ” 7    πŸ’¬ 21    πŸ“Œ 0

These are awesome! Best of luck on your defense.

20.08.2025 23:23 β€” πŸ‘ 4    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Slightly diminish a band:
The green mild bell peppers

13.08.2025 03:54 β€” πŸ‘ 9    πŸ” 2    πŸ’¬ 0    πŸ“Œ 0

Was great to see you again Nadine! Have a safe trip back.

07.08.2025 16:06 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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Conferencing with my favorite natural product chemist this week at the #ASP2025 in Grands Rapids, Michigan. Great science, inspiring talks, and reconnecting with friends and colleagues! @claesengroup.bsky.social @eustaquiolab.bsky.social @balunaslab.bsky.social #SecMet #NaturalProducts

07.08.2025 12:49 β€” πŸ‘ 8    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0
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β€˜This wasn’t obvious’: the potato evolved from a tomato ancestor, researchers find Hybridisation event took place about 9 million years ago, helping to β€˜spark the emergence of a new organ’

Potato, potahto, tomato, tomahto
Let's call the whole thing off 🎢🎢

www.theguardian.com/science/2025...

04.08.2025 14:25 β€” πŸ‘ 7    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
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ZiemertLab The Ziemert lab is interested in the evolution and distribution of bacterial secondary metabolites. These bioactive compounds are especially important in human medicine as the chemical scaffolds are t...

Check out the Ziemert Lab’s new YouTube channel
m.youtube.com/@ZiemertLab
We’ve uploaded short tutorial videos on how to use our tools for genome mining and natural product discovery.
Thanks Semih, @martinaadamek.bsky.social @turgutmesut.bsky.social ! #GenomeMining #SecMet #naturalproducts

08.07.2025 20:09 β€” πŸ‘ 48    πŸ” 25    πŸ’¬ 2    πŸ“Œ 1

I don't know, just one of our bad habits?

Though when I submit way ahead of time, somehow the grants office ends up sending in last minute anyways.

Even while I am away on travel (with due advance notice) πŸ€·β€β™‚οΈ

I guess we're not alone in our bad habits 😁

15.07.2025 02:53 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Less favorite but also interesting is how several Corynes smell like moist armpit 😝

15.07.2025 02:41 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

My favorite is hands down the wet forest soil smell of Streptomyces πŸ₯°

15.07.2025 02:38 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
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NASA is more than rockets and moonwalks. NASA is behind much of our everyday technology. From space discovery, to Air Jordans, to CAT scans, NASA has played a role. We get it all on less than a penny of every federal dollar. Now their science may be gutted by 50%.
#NASADidThat

10.07.2025 22:39 β€” πŸ‘ 8044    πŸ” 2619    πŸ’¬ 257    πŸ“Œ 184
Photo of Djenet Bousbaine

Photo of Djenet Bousbaine

πŸŽ‰ Congratulations to Djenet Bousbaine, winner of the 2025 NOSTER & Science Microbiome Prize for her work to illuminate how the immune system responds to the beneficial skin microbiome.

Learn more: scim.ag/4lVwpFx

04.07.2025 14:07 β€” πŸ‘ 97    πŸ” 15    πŸ’¬ 2    πŸ“Œ 1
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The new open access policy of NIH will take effect next week (July 1st). All NIH funded research πŸ”¬πŸ§ͺ🧬accepted after July 1st must be open access upon publication. Worried about fees? πŸ’Έ Check out how IAI stacks up against other journalsβ€”you might be surprised. #OpenAccess #SciComm #Microbiology

26.06.2025 21:47 β€” πŸ‘ 35    πŸ” 21    πŸ’¬ 0    πŸ“Œ 2

When all this pollution is causing you headaches...

πŸ’ͺ🦠

24.06.2025 11:26 β€” πŸ‘ 10    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
An empty booth at ASM that should have housed the NSF

An empty booth at ASM that should have housed the NSF

Well this is f’in sad #ASMicrobe

21.06.2025 20:40 β€” πŸ‘ 200    πŸ” 40    πŸ’¬ 2    πŸ“Œ 5
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Genomics of host–microbiome interactions in humans Nature Reviews Genetics - In this Review, Ferretti et al. discuss advances in our understanding of interactions between the human genome and the microbiome, including the effects of the microbiome...

Interested in microbiome GWAS and heritability studies? Check out our new Review in Nature Reviews Genetics! We explore key findings, challenges, and future directions of the field.
rdcu.be/epoRR

@blekhman.bsky.social @sambhawa.bsky.social and Dr. Kelsey Johnson.

04.06.2025 16:52 β€” πŸ‘ 48    πŸ” 27    πŸ’¬ 3    πŸ“Œ 3
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Pooled analysis of 3,741 stool metagenomes from 18 cohorts for cross-stage and strain-level reproducible microbial biomarkers of colorectal cancer - Nature Medicine An analysis of 18 metagenomic datasets of individuals with colorectal cancer, adenomas and healthy controls yields improved cancer prediction accuracy based solely on gut metagenomics, as well as the ...

πŸ₯NEW publication from our lab:
the largest meta-analysis of gut microbiome associations with CRC!

www.nature.com/articles/s41...

πŸ§΅β¬‡οΈ

1/6

03.06.2025 10:43 β€” πŸ‘ 42    πŸ” 22    πŸ’¬ 3    πŸ“Œ 1