January 12th 2026

 
 

EARA News Digest 2026 - Week 3


Welcome to your Monday morning update, from EARA, on the latest news in biomedical science, policy and openness on animal research. 

This week: Gut microbes from primates change brain gene activity in miceVitamin C protects fish reproductive healthCancer protein affects the heart in mice.
 

Gut microbes from primates change brain gene activity in mice 

Research from the US suggests primate gut microbes influence brain-related gene activity in mice, indicating a potential role in the evolution of large brains. 

The human brain is exceptionally large and energy-intensive, even among primates. Its evolution remains an open question. Scientists now focus on the gut microbiome, the community of microbes in the intestine, as it influences human biological processes like metabolism, brain signalling and development.  

A team at Northwestern University tested how transferring primate microbiomes to mice affects rodent brain activity. They used microbes from humans, squirrel monkeys (large-brained primates) and macaques (smaller-brained primates).  

After colonisation of the microbiome, the team analysed brain gene expression patterns in the germ-free mice and compared them with data from primate brains. Mice receiving microbes from humans or squirrel monkeys showed increased activity in genes linked to brain energy use and learning-related processes, mimicking the donors’ gene expression.  

In contrast, mice colonised with macaque microbes showed different gene expression patterns, including activity associated with several neurodevelopmental and psychiatric conditions.  

Katherine Amato from Northwestern University, lead author of the study published in PNAS, said: “Based on our findings, we can speculate that… if you don't get exposed to the ‘right’ human microbes in early life, your brain will work differently, and this may lead to symptoms of these conditions.”  

Future research will explore the origins of psychological disorders and the evolutionary impact of microbes on brain physiology.

 

 

 

Vitamin C protects fish reproductive health  

Researchers in the US have discovered that vitamin C may protect reproductive health in fish from an emerging environmental contaminant widely used in industry and explosives.  

Researchers at the University of Missouri started investigating this subject after discovering that military personnel, who are regularly exposed to explosives, are more likely to face reproductive issues.  

“Fish are good models for studying reproductive health because their reproductive genes and processes are similar to humans,” explained Ramji Bhandari, from the University of Missouri and lead author of the study published in Environmental Science & Technology

By exposing male medaka fish, a well-studied fish whose genome is already known, to potassium perchlorate, they discovered that the fish had lower fertility rates and structural and genetic alterations in the testes, including genes associated with the response to harmful oxygen-derived metabolic byproducts. When fish were exposed to vitamin C at the same time, a well-known antioxidant, the detrimental effects on fertility were mitigated. 

Future research may address how vitamin C could be used to protect reproductive health of both wildlife and humans, especially at-risk groups like the military or industry workers.

 

 

 
 

Cancer protein affects the heart in mice

A study in Germany using mice has revealed that a protein linked to cancer also affects the heart. 

Cancer cells grow uncontrollably because they can avoid cell death and change how they produce energy.  

Using melanoma cells and mice with tumours derived from these cells, researchers at Technische Universität Dresden found that a protein called MCL1, previously known for helping cancer cells survive, also promotes tumour growth in mice.  

Drugs that block MCL1 are promising for cancer treatment and are currently being tested in clinical trials. However, some patients experience severe heart damage.

This is why researchers tested the effects of blocking human MCL1 in mice genetically engineered to produce it. They found that blocking the protein increased heart damage, but leucine diet-supplementation reduced this effect. 

“The protein [MCL1] actively intervenes in key metabolic and growth signalling pathways, thereby linking two fundamental cancer mechanisms,” said Mohamed Elgendy, from Technische Universität Dresden and lead author of the study published in Nature Communications

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