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What’s in a belly?

January 2, 2013

A microbiome, a world teeming with single-celled organisms, a.k.a. bacteria.

Consider yourself endowed with a newly-named organ. You’ve got heart, lungs, kidneys. Now add “microbiome” to the inventory.

The population of microbes in your gut is big. The 100 trillion bacteria in your gut represent ten times the number of cells in your body that pack your personal brand of DNA. Of all the cells you tote around, only 10% are genetically you. The rest are bacteria, as many as 1,000 different species flaunting 3.3 million unique genes. That’s 150 times the number of genes coded into your 46 chromosomes. That’s a lot of adjunct bio-programming power.

Although the number of microbes is huge, as individuals they’re tiny. Consequently, your gut microbiome comes in at 1 to 3 percent of your body’s mass. A 125-pound adult, for example, is toting between 1.25 and 3.75 pounds of bacteria.

Do not consider eliminating these bacteria for an easy four-pound weight loss. You need them. They’re essential to your physical health and mental sanity.

The roster of bacteria in your gut — which kinds are present in what proportions — depends on factors such as what you eat, which drugs you’ve taken, and how well your immune system is functioning. Depending on the diversity of and balance among your gut-based bacteria, the microbes are busy promoting digestion, making nutrients, secreting enzymes, eliminating infections, influencing mood and behavior.

Mood and behavior? In the summer 2007 issue of the Belly Bulletin, I featured an excerpt from Gut & Psychology Syndrome, the book in which British neurologist and nutritionist Dr. Natasha Campbell-McBride reveals the gut microbiome’s influence on the body-mind, especially in relation to childhood autism. She suggests ways to reestablish a healthy population of gut bacteria, largely through a set of food choices that regulate carbohydrates.

A few months after posting the excerpt, I received this news from a reader:

I bought Gut & Psychology Syndrome for a friend whose four-year-old had been diagnosed with autism. He wasn’t speaking.

Then, after being on the diet the book recommends for less than a month, he started speaking in complete sentences and making marked improvements in other areas.

Autism is only one of several body-mind disorders that scientists are considering in relation to what’s going on in the gut. The status of your belly-based bacteria may, for example, play a key role in obesity, irritable bowel syndrome, inflammatory bowel disease, autoimmune diseases, allergies, and metabolic syndrome — the collection of risk factors, including insulin resistance, that increase the likelihood of coronary artery disease, stroke, and diabetes.

The current epidemic of intestinal infection with Clostridium difficile, contributing to more than 110,000 deaths per year, has focused all the more attention on the gut microbiome. Because this pathogen forms drug-resistant spores, treatment with antibiotics is frequently ineffective. In fact, previous use of antibiotics has typically destroyed the beneficial bacteria that, if present, could eliminate the infection.

Fecal microbial transplantation, though, has demonstrated more than a 90% cure rate. A sample of bacteria from the gut of a healthy donor, introduced into the patient’s intestine, restores the patient’s microbiome and its ability to eliminate the Clostridium infection.

Fecal microbial transplantation figures in research regarding behavior as well as immunity. Dr. Mark Lyte’s experiments with mice, for example, show that patterns of anxiety and specific responses to stress can be introduced or eliminated depending on what microbes set up shop in the rodent’s gut. The ways in which the microbiome figures in gut-brain communication remain to be detailed.

Whatever the details may be, fecal microbial transplantation has a long history as a protocol for healing. Perhaps the first documentation in Western literature points to the 17th century Italian anatomist Fabricius Aquapendente and his application of fecal microbial transplantation in veterinary medicine.

According to Dr. Faming Zhang and his colleagues, the record of fecal microbial transplantation in China dates to the 4th century. Described in handbooks of emergency and traditional medicine, the practice “was considered a medical miracle that brought patients back from brink of death” due to food poisoning and severe diarrhea.

Venus of Lespuge

Venus of Lespugue

The Venus of Lespugue, a six-inch tall statuette discovered in 1922 in the foothills of the Pyrenees, was carved from tusk ivory at some point 26,000 to 24,000 years ago. Some investigators suggest the opening between the buttocks functioned as a vessel for microbial transplantation.

While fecal microbial transplantation may have a long history among traditional cultures in China and elsewhere, so do cuisines that enrich the gut microbiome with fermented foods in the form of pickled vegetables, sour milk beverages, soups, and breads. These foods from cultures on every continent — such as natto, miso, tempeh, kombucha, kimchi, sauerkraut, kefir, yogurt, buttermilk, borscht, and sourdough — restore and fortify the gut’s population of beneficial bacteria, a.k.a probiotics.

Breathing and movement exercises that compress and churn the gut also have a long history, in terms of traditional dance, healing ritual, and spiritual practice. For example, age-old yoga practices such as kapalabhati, agni sara, uddiyana bandha, and nauli (and the power-centering exercises in the Honoring Your Belly practice) mobilize the belly. Doing so, they have the potential to activate the gut microbiome and its healing properties.

Taking the perspective of the Asian healing arts, the body-mind functions according to the flow of life force concentrated in various energy centers and coursing through the body’s meridians. Applying this perspective to the gut microbiome, I wonder how the energetic field of all those bacteria interact with the belly-centered energy field called the hara in Japanese, the lower tan tien in Chinese. Likewise, how does the gut microbiome’s energy field interact with the Large Intestine and Small Intestine meridians? How does the Triple Warmer meridian, linking energy centers in hara, heart, and head, figure in gut-brain communication?

Whatever the details, both Western and Eastern perspectives are illuminating the intricate relationships between the belly and the body-mind. Both suggest that what we put into our bodies, and what comes out of our bodies, is sacred — pertinent to survival.


Angelica, A. Can taking probiotics improve your mental health?: Kurzweil

Borody, T. et. al. Fecal microbiota transplantation and emerging applications: Nature Reviews Gastroenterology and Hepatology

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Gordon, J. et. al. Extending Our View of Self: the Human Gut Microbiome Initiative (HGMI)

Hadhazy, A. Think Twice: How the Gut’s “Second Brain” Influences Mood and Well-Being: Scientific American

Hudson, W. Little-known fecal transplant cures woman’s bacterial infection: CNN

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Lyte, M. Probiotics function mechanistically as delivery vehicles for neuroactive compounds: Microbial endocrinology in the design and use of probiotics: BioEssays

MacDougall, R. NIH Human Microbiome Project defines normal bacterial makeup of the body: NIH News

McKenna, M. Swapping Germs: Should Fecal Transplants Become Routine for Debilitating Diarrhea?: Scientific American

Ortiz, E. Fecal transplant: Sounds gross but saves lives: NY Daily News

Shin, L. Fecal transplants hold promise, but face regulatory hurdles: Smart Planet

Tilg, H. et. al. Gut microbiome, obesity, and metabolic dysfunction: The Journal of Clinical Investigation

Wiley-Blackwell. A gut-full of probiotics for your neurological well-being: Science Daily

Williams, D. Traditional Fermented Foods: How They Aid Digestion: Dr. David Williams

Zhang, F. et. al. Should We Standardize the 1,700-Year-Old Fecal Microbiota Transplantation?: The American Journal of Gastroenterology

Zhu, B. et. al. Human gut microbiome: the second genome of human body: Protein & Cell

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