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The average human gut is home to perhaps 500 to 1,000 different species of bacteria.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
Aspirin is the most widely used drug in the world. It has even been recognized as such by the Guinness Book of World Records.
In women, pharmacodynamic differences include increased sensitivity to (and increased effectiveness of) beta-blockers, opioids, selective serotonin reuptake inhibitors, and typical antipsychotics.
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