New Hypothesis Unifies Several Contrasting Theories That May Help Explain the Underlying Cause of IBS

[Health Reporter]

Am J Gastroenterol. 2022 Dec 1;117(12):1933-1947. doi: 10.14309/ajg.0000000000002066. Epub 2022 Dec 1.

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.

PMID:36455220 | DOI:10.14309/ajg.0000000000002066

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[Jeffrey Roberts]

New Hypothesis Unifies Several Contrasting Theories That May Help Explain the Underlying Cause of IBS

A new theory suggests irritable bowel syndrome (IBS), the most common gastrointestinal disorder, may be caused by gravity.

Brennan Spiegel, MD, MSHS, director of Health Services Research at Cedars-Sinai and author of the hypothesis, explains that IBS—and many other conditions—could result from the body’s inability to manage gravity.

“As long as there’s been life on Earth, from the earliest organisms to Homo sapiens, gravity has relentlessly shaped everything on the planet,” said Spiegel, who is also a professor of Medicine. “Our bodies are affected by gravity from the moment we’re born to the day we die. It’s a force so fundamental that we rarely note its constant influence on our health.”

The hypothesis, published in the American Journal of Gastroenterology, describes 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.”

 

The underlying mechanism of IBS has been puzzling researchers since it was first described over a century ago. While the disorder affects up to 10% of the world’s population, experts still aren’t sure exactly how or why it develops. 

There are, however, several contrasting theories that explain its clinical features. One is that IBS is a gut-brain interaction disorder; evidence shows that neuromodulators and behavioral therapies are effective. Another theory holds that IBS is driven by abnormalities in the gut microbiome, which can be managed with antibiotics or low fermentable diets.

Other theories suggest that abnormalities in motility, gut hypersensitivity, abnormal serotonin levels or a dysregulated autonomic nervous system cause IBS.

“There’s such a variety of explanations that I wondered if they could all be simultaneously true,” said Spiegel. “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.” 

Gravity can compress the spine and decrease one’s flexibility. It can also cause organs to shift downward, moving from their proper position. The abdominal contents are heavy, like a sack of potatoes that we’re destined to carry our entire lives, Spiegel explained. 

“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,” Spiegel said.

Some people have bodies that are more capable of carrying the load than others. For example, some have “stretchy” suspension systems that cause the intestines to droop down. Others have spinal issues that cause the diaphragm to sag or the belly to protrude, leading to a compressed abdomen. 

These factors might trigger motility problems or bacterial overgrowth in the gut. This may also help explain why physical therapy and exercise is effective for IBS because these interventions strengthen the support systems. 

 

People with IBS might be prone to over-predicting G-force threats that never occur. Photo by Getty.

The gravity hypothesis, however, also goes beyond the intestines. 

 

“Our nervous system also evolved in a world of gravity, and that might explain why many people feel abdominal ‘butterflies’ when anxious,” said Spiegel. “It’s curious that these ‘gut feelings’ also occur when falling toward Earth, like when dropping on a roller coaster or in a turbulent airplane. The nerves in the gut are like an ancient G-force detector that warns us when we’re experiencing—or about to experience—a dangerous fall. It’s just a hypothesis, but people with IBS might be prone to over-predicting G-force threats that never occur.”

Some people are more resilient to G-forces than others. For example, one person may raise their hands and grin while dropping on a roller coaster while another grits their teeth and groans. The first person is amused while the second feels threatened, revealing a spectrum of what Spiegel calls “G-force vigilance.”  

Another contributor that may play a role is serotonin, a neurotransmitter that may have evolved in part to manage gravity across body systems. Serotonin is necessary for mood elevation, both metaphorically and literally, noted Spiegel. Without it, people also would not be able to stand up, maintain balance, circulate blood, or pump intestinal contents against gravity.

“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.”

Further research is needed to test this approach and the possible treatments.

“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.”

Listen to the AJG Podcast to hear more from Spiegel on how gravity may cause IBS.

Follow Cedars-Sinai Academic Medicine on Twitter for more on the latest basic science and clinical research from Cedars-Sinai. 

© 2022 Cedars-Sinai. All Rights Reserved. 

[Jeffrey Roberts]

"Every fiber of our body is affected by gravity. That's no mystery. But it's interesting to explore how we evolved to manage gravity & consider what happens when we struggle w/ this universal force." B. Spiegel

[Jeffrey Roberts]

Blame IBS on Gravity Intolerance?  Medscape

The precise cause of irritable bowel syndrome (IBS) remains a mystery. A novel new hypothesis suggests that IBS could result from the body's inability to manage gravity.

Gravity may be the "unifying factor in multiple seemingly disparate and mutually incompatible theories of IBS," Brennan Spiegel, MD, director of Health Services Research at Cedars-Sinai Medical Center, Los Angeles, California, told Medscape Medical News. Spiegel's gravity hypothesis of IBS is described in an article published in the December issue of American Journal of Gastroenterology.

A human being's relationship to gravity is not unlike the relationship of a fish to water, he explained.

"We live our entire life in it, are shaped by it, yet hardly notice its ever-present influence on our body. Every fiber of our body is affected by gravity every day, including our gastrointestinal tract," said Spiegel.

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[Jeffrey Roberts]

IBS affects more than 10% of Americans. Could it be caused by gravity? - Yahoo! Life

Could gravity be the root cause behind a common gastrointestinal disorder? That’s what a new hypothesis from Dr. Brennan Spiegel, published in The American Journal of Gastroenterology, suggests could be the unifying factor behind cases of irritable bowel syndrome (IBS).

First, what is IBS? According to Dr. Subhankar Chakraborty, an assistant professor in the division of gastroenterology, hepatology and nutrition at The Ohio State University Wexner Medical Center, IBS is a disorder of brain-gut interaction.

“IBS is characterized by a combination of persistent and repeated episodes of abdominal pain associated with a change in stool consistency,” he notes. “So patients with IBS either experience difficulty with constipation or diarrhea, or have abdominal pain that is typically brought on by eating and is relieved after a bowel movement.”

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[Jeffrey Roberts]

Q&A: Gravity’s role in IBS pathogenesis, symptoms: A new hypothesis

Irritable bowel syndrome may result from ineffective anatomical, physiological and neuropsychological gravity-management systems, a researcher theorized in an article published in The American Journal of Gastroenterology. 

“Our relationship to gravity is not unlike the relationship of a fish to water: We live our entire life in it, are shaped by it, yet hardly notice its ever-present influence on our body,” Brennan Spiegel, MD, MSHS,director of health services research and professor of medicine and public health at Cedars-Sinai Health System in Los Angeles, told Healio.

>> Read the full Q & A article