Category Biology/Biotechnology

Night owl or early bird? Study finds sleep categories aren’t that simple

Woman sleeping in bed
Image by Getty Images.

The familiar labels “night owl” and “early bird,” long used in sleep research, don’t fully capture the diversity of human internal clocks, a new study has found. The McGill University-led study published in Nature Communications found the two sleep-wake patterns, called chronotypes, contain a total of five distinct biological subtypes, each associated with different patterns of behavior and health.

A chronotype is based on the parts of a 24-hour period when a person naturally feels most alert or ready to sleep. Previous research has linked late chronotypes to worse health outcomes, but results have often been inconsistent. The new findings help explain why, the authors said.

“Rather than asking whether night owls are more at risk, the better question may be...

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Gut-derived metabolite hippuric acid ‘turns up’ immune inflammation, study finds

Scientists discover how gut-derived metabolite acts as immune 'Volume knob' via macrophages
Graphical abstract. Credit: Cell Reports (2026). DOI: 10.1016/j.celrep.2025.116749

Scientists at The Wistar Institute have identified a previously overlooked mediator in the body’s response to life-threatening infections: hippuric acid, a metabolite produced when gut bacteria break down polyphenols from berries, tea, and other plant-based foods. The research reveals that this molecule acts as an immune-system amplifier, boosting the body’s inflammatory defenses during early infection but elevating them to deadly levels when infections progress to sepsis.

Published in Cell Reports, the study demonstrates that elevated hippuric acid levels correlate with increased mortality in sepsis patients, while also uncovering the molecular mechanisms by which this metabolite modifies immune re...

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How your life story leaves epigenetic fingerprints on your immune cells

How do nature and nurture shape our immune cells?

The COVID-19 pandemic gave us tremendous perspective on how wildly symptoms and outcomes can vary between patients experiencing the same infection. How can two people infected by the same pathogen have such different responses? It largely comes down to variability in genetics (the genes you inherit) and life experience (your environmental, infection, and vaccination history).

These two influences are imprinted on our cells through small molecular alterations called epigenetic changes, which shape cell identity and function by controlling whether genes are turned “on” or “off.”

Salk Institute researchers are debuting a new epigenetic catalog that reveals the distinct effects of genetic inheritance and life experience on various types of immune cells...

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Single gene found to influence gut bacteria balance and IBD susceptibility

Declan McCole

Two recent studies from the University of California, Riverside, published in the same issue of Gut Microbes highlight the role of a gene called PTPN2 in protecting the gut from harmful bacteria linked to inflammatory bowel disease (IBD).

Led by Declan McCole, a professor of biomedical sciences in the School of Medicine, the studies show that when PTPN2 does not function properly, the gut becomes more vulnerable to infection and inflammation.

People with IBD often have higher levels of AIEC, a harmful type of E. coli bacteria. AIEC can attach to the gut lining, invade gut cells, damage the gut’s protective barrier, and worsen inflammation.

Normally, PTPN2 helps maintain gut health by controlling inflammation and supporting a balanced gut microbiome...

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