Python's Fasting Ability Yields New Anti-Obesity Compound With Human Potential

Burmese pythons can survive months — up to a year — without eating after a single meal. This extreme survival ability is now emerging as a new key to developing obesity treatments.

"The reason they don't feel hungry after eating"… A substance found in pythons

A joint research team from Stanford University, the University of Colorado Boulder, and Baylor College of Medicine has discovered a key metabolite in python blood that suppresses appetite, according to the Guardian and other international media outlets on Saturday.

The Burmese python, the subject of the study, can swallow prey equivalent to its own body weight in a single meal and then fast for months, up to more than a year. Immediately after eating, the snake's heart enlarges by approximately 25% and its metabolic rate surges up to 4,000-fold — extreme physiological responses entirely unlike those seen in humans.

The researchers fed pythons that had been fasted for 28 days and then analyzed their blood, confirming that more than 200 metabolites increased within hours after the meal. One compound in particular, para-tyramine-O-sulfate (pTOS), surged up to 1,000-fold and was identified as the key substance. The compound is produced by gut microbiota and is known to exist in small amounts in the human body as well.

Different from existing drugs… "Potential to reduce side effects"

The most notable characteristic of pTOS is its "selective appetite suppression."

In animal experiments, the compound reduced appetite without affecting energy expenditure or organ size. When administered to obese mice, food intake decreased and body weight dropped approximately 9% over four weeks.

This represents a different mechanism of action from the GLP-1 class of obesity drugs currently in use. While existing drugs reduce appetite by slowing gastric emptying, pTOS was found to act directly on the hypothalamus in the brain to regulate appetite itself.

This raises the possibility of reducing the typical side effects of existing drugs, such as nausea and abdominal pain. Leslie Leinwand, the professor who led the research, said, "This is a new candidate compound that can suppress appetite without side effects," adding, "There are also expectations for safety given that the substance already exists in the human body."

"There is no hunger to begin with"… Another secret of snakes

The python's unusual survival strategy does not end there.

In February, a research team at the University of Porto published findings showing that snakes either lack the gene that produces ghrelin — the hormone that stimulates appetite — or have it in a nearly nonfunctional state. The study was published in Royal Society Open Biology.

In other words, pythons may not simply suppress appetite but rather possess an entirely different "hunger system" from humans.

Experts say that if these lines of research are combined, they could lead to next-generation obesity treatment strategies that go beyond merely reducing appetite to "redesigning the appetite mechanism itself."

The findings were published in the international journal Nature Metabolism.