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Reference Terms
from Wikipedia, the free encyclopedia

Pathogen

A pathogen or infectious agent is a biological agent that causes disease or illness to its host. The term is most often used for agents that disrupt the normal physiology of a multicellular animal or plant. However, pathogens can infect unicellular organisms from all of the biological kingdoms. There are several substrates and pathways whereby pathogens can invade a host. The human body contains many natural defenses against some of common pathogens in the form of the human immune system and by some "helpful" bacteria present in the human body's normal flora. Some pathogens have been found to be responsible for massive amounts of casualties and have had numerous effects on afflicted groups. Today, while many medical advances have been made to safeguard against infection by pathogens, through the use of vaccination, antibiotics and fungicide, pathogens continue to threaten human life. Social advances such as food safety, hygiene, and water treatment have reduced the threat from some pathogens.

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Health & Medicine News

April 17, 2026

Scientists have uncovered a surprising twist in how bacteria share genes—including those that spread antibiotic resistance. Tiny virus-like particles called gene transfer agents (GTAs), once ...
Sparkling water is often seen as a simple, healthy drink—but could it also help with weight loss? New research suggests it may slightly boost how the body processes blood sugar and energy. However, the effect is very small, meaning it’s no ...
A hormone called FGF21 can reverse obesity in mice by activating a newly identified brain circuit tied to metabolism. Surprisingly, it works in the hindbrain—the same region targeted by GLP-1 drugs like Ozempic and Wegovy—but through a ...
Researchers have found a way to make cancer-killing immune cells more powerful and precise. By adding specific signaling components, they boosted the cells’ readiness to attack tumors. Surprisingly, briefly suppressing the cells with a drug before ...
Scientists have discovered that a protein linked to cell death is secretly driving the aging of blood stem cells in a completely different way. Instead of killing the cells, it damages their mitochondria, sapping their energy and weakening the ...
A rogue set of “zombie” immune cells may be driving aging and fatty liver disease by flooding tissues with inflammation. Researchers found these cells accumulate with age and high cholesterol—and can make up most of the liver’s immune cells ...
A massive, nearly 20-year study tracking over 650,000 Americans with irritable bowel syndrome is raising new questions about the long-term safety of common treatments. Researchers found that some widely used medications—including antidepressants ...
New research suggests that aiming for a lower blood pressure target may deliver bigger heart health benefits than previously thought. Using large datasets and simulation models, scientists found that keeping systolic blood pressure below 120 mm Hg ...
A massive Swedish study shows that AI can spot people at higher risk of melanoma using routine health data. Advanced models significantly outperformed basic methods, identifying high-risk groups with striking accuracy. Some individuals flagged by ...
A surprising discovery from high-altitude animals like yaks and Tibetan antelopes could reshape how we treat nerve damage in humans. Scientists found that a genetic mutation helping these animals survive low-oxygen environments also protects and ...
A surprising new clinical trial has revealed that metformin—a cheap, century-old drug widely used for type 2 diabetes—may help people with type 1 diabetes in an unexpected way. While researchers initially hoped it would reduce insulin ...
A lifetime of mental stimulation—like reading, writing, and learning new skills—may help protect the brain as we age. People with the highest levels of cognitive enrichment had a much lower risk of Alzheimer’s and experienced symptoms years ...

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updated 12:56 pm ET