Research says gravity could be to blame for irritable bowel syndrome

"As I thought about each theory, from those involving motility to bacteria, to the neuropsychology of IBS, I realized they might all point back to gravity as a unifying factor. It seemed pretty strange at first, no doubt, but as I developed the idea and ran it by colleagues, it started to make sense," he said.

IBS symptoms can occur alongside musculoskeletal problems

The hypothesis, published in the American Journal of Gastroenterology, elaborates how the intestines, spine, heart, nerves, and brain evolved to manage gravity. 

"Our body systems are constantly pulled downward," Spiegel noted. "If these systems cannot manage the drag of gravity, then it can cause issues like pain, cramping, lightheadedness, sweating, rapid heartbeat, and back issues—all symptoms seen with IBS. It can even contribute to bacterial overgrowth in the gut, a problem also linked to IBS."

Spiegel described the body as a "sack of potatoes that we're destined to carry our entire lives."

"The body evolved to hoist this load with a set of support structures. If these systems fail, then IBS symptoms can occur along with musculoskeletal problems," he said.

Physical therapy and exercise are effective for IBS

While some bodies are more capable of carrying the load (organs) than others, like "stretchy" suspension systems that can cause the intestines to hang, others have spinal issues that cause the diaphragm to sag or the belly to protrude, thereby resulting in a compressed abdomen, as per the release.

Such factors induce bacterial overgrowth in the gut or motility problems. Which explains why physical therapy and exercise are effective for IBS as they strengthen the "support systems."

Serotonin, a neurotransmitter, can also play a role. People would be unable to perform basic tasks like standing up by themselves or maintaining balance. 

"Dysregulated serotonin may be a form of gravity failure," Spiegel said. "When serotonin biology is abnormal, people can develop IBS, anxiety, depression, fibromyalgia, and chronic fatigue. These may be forms of gravity intolerance."

A major paradigm shift

More research is required to develop appropriate treatments for the same. 

"This hypothesis is very provocative, but the best thing about is that it is testable," said Shelly Lu, MD, the Women's Guild Chair in Gastroenterology and director of the Division of Digestive and Liver Diseases at Cedars-Sinai. "If proved correct, it is a major paradigm shift in the way we think about IBS and possibly treatment as well."

Study Abstract:

The pathogenesis of irritable bowel syndrome (IBS)—a disorder of gut-brain interaction that affects up to 10% of the world's population—remains uncertain. It is puzzling that a disorder so prevalent and archetypal among humans can be explained by disparate theories, respond to treatments with vastly different mechanisms of action, and present with a dazzling array of comorbidities. It is reasonable to question whether there is a unifying factor that binds these divergent theories and observations, and if so, what that factor might be. This article offers a testable hypothesis that seeks to accommodate the manifold theories, clinical symptoms, somatic comorbidities, neuropsychological features, and treatment outcomes of IBS by describing the syndrome in relation to a principal force of human evolution: gravity. In short, the hypothesis proposed here is that IBS may result from ineffective anatomical, physiological, and neuropsychological gravity management systems designed to optimize gastrointestinal form and function, protect somatic and visceral integrity, and maximize survival in a gravity-bound world. To explain this unconventional hypothesis of IBS pathogenesis, referred to herein as the gravity hypothesis, this article reviews the influence of gravity on human evolution; discusses how Homo sapiens imperfectly evolved to manage this universal force of attraction; and explores the mechanical, microbial, and neuropsychological consequences of gravity intolerance with a focus on explaining IBS. This article concludes by considering the diagnostic and therapeutic implications of this new hypothesis and proposes experiments to support or reject this line of inquiry. It is hoped that the ideas in this thought experiment may also help encourage new or different ways of thinking about this common disorder.