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physiology

Illustration of gut sending signals to kidneys.
physiology

How Bacteria Help Regulate Blood Pressure

Kidneys sniff out signals from gut bacteria for cues to lower blood pressure after meals. Our understanding of how the symbiotic microbes affect health is becoming much more molecular.

Illustration: sliced tooth showing tree rings
chronobiology

Teeth May Reveal a Multi-Day Biological Clock

Tiny lines laid down by tooth enamel appear to reveal a previously unknown biological rhythm. If confirmed, the finding could help researchers understand why big animals grow slower — and live longer — than small ones.