We stand on the threshold of a microbiotic renaissance, according to some physicians and microbiologists. As our understanding of this long-neglected field expands, so too will our treatment options.
As we mentioned, the place to start -- at least where fecal transplantation is concerned -- remains Clostridium difficile. According to the CDC, C. difficile infections kill 14,000 people in the United States annually, and its occurrence among hospitalized patients more than doubled from 2000 to 2009 [sources: Hudson; Zimmer]. One long-term follow-up study of 77 fecal transplant patients reported a 91 percent cure rate after just one fecal transplant, and a 98 percent cure rate with additional probiotics, antibiotics or fecal transplants [source: Brandt et al.].
Fecal microbiota might also hold answers for people with metabolic syndrome -- a collection of co-occurring risk factors, such as insulin resistance and extra weight around the middle, that increases the chance of coronary artery disease, stroke and type 2 diabetes [source: A.D.A.M.]. In some studies, fecal transplantation in metabolic syndrome patients reduced triglyceride levels and improved insulin sensitivity [source: Allen; Gewirtz].
Scientists have also tied obesity in rats to changes to the gut's microbiome. The intestines of obese persons contain a different set of microbes than those of non-obese persons, and clinical trial results suggest lean donors might help obese recipients lose weight by changing how they metabolize sugars [source: Zimmer].
"The composition and activity of gut microbiota is different in lean and obese individuals," says Dr. Alexander Khoruts, associate professor of medicine at University of Minnesota. "We know that animal energy metabolism can be changed by fecal microbiota transplantation. It is possible there will be something along these lines in humans."
"However, it is also clear that diet and lifestyle choices influence the composition of gut microbiota."
Indeed, we're only beginning to grasp the possibilities for fecal transplants and macrobiotics in general [source: Khoruts]. Don't confuse the two, however. Gut flora, though numerous, represent only a portion of total body microbes. Moreover, we do not yet fully understand the relationships between microbiota, health and disease, whether in the intestines or outside of them.
For example, a number of medical conditions may be linked to the intestine, including liver disease, migraines, chronic fatigue, rheumatoid arthritis, multiple sclerosis, Alzheimer's disease and Parkinson's disease, but how (or if) they relate to microbial therapy or fecal transplants remains unclear and will require substantial studies to answer [sources: Allen; Borody; Borody; Khoruts].
In the meantime, don't be too quick to "poo-poo" the idea of fecal transplantation. It's effective, fast and seems to have no side effects. But, as with any new therapy, we'll have to wait and see how it comes all out in the end.
Authors Note: How Fecal Transplants Work
No matter how long I report on science, it never ceases to surprise. Perhaps there is nothing new under the sun, but what about where the sun doesn't shine?
Vulgarities and terrible puns aside, few things are as fun for a science journalist as when scientists or doctors point to something we take for granted and say, "Hmm, maybe this is more important than we thought," or, "Perhaps our assumptions are completely out of whack and we need a paradigm that's less than a century old."
Such cycles are a natural part of science. Research, after all, runs hot and cold, and yesterday's apparent dead-end can later open up into today's road to discovery. All it takes is a pair of fresh eyes and the context provided by time and further research.
- Aagaard, Kjersti et al. "A Metagenomic Approach to Characterization of the Vaginal Microbiome Signature in Pregnancy." PLoS ONE. Vol. 7, no. 6. June 2012. (Oct. 30, 2012) http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0036466
- A.D.A.M. Medical Encyclopedia. "Metabolic syndrome." June 2, 2012. (Nov. 9, 2012) http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0004546/
- Allen, Jane. "Diarrhea, Debilitating Digestive Ills Relieved With DIY Fecal Transplants." ABC News. May 16, 2011. (Oct. 30, 2012) http://abcnews.go.com/Health/diarrhea-debilitating-digestive-ills-relieved-diy-fecal-transplants/story?id=13601702#.UIrv_8XA_ZA
- Bakken, Johan, et al. "Treating Clostridium difﬁcile Infection with Fecal Microbiota Transplantation." Clinical Gastroenterology and Hepatology. Vol. 9. Page 1044. December 2011. (Oct. 29, 2012) http://www.cdd.com.au/pdf/publications/All%20Publications/2011-Treating%20Clostridium%20difficile%20infection%20with%20fecal%20microbiota%20transplantation,%20Fecal%20microbiota%20transplantation%20Workgroup,%20Clin%20Gastroenterol%20and%20Hep.pdf
- BBC. "Dung-eater." (Nov. 1, 2012) http://www.bbc.co.uk/nature/adaptations/Coprophagia
- Biello, David. "The Origin of Oxygen in Earth's Atmosphere." Scientific American. Aug. 19, 2009. (Oct. 29, 2012) http://www.scientificamerican.com/article.cfm?id=origin-of-oxygen-in-atmosphere
- Borody, Thomas. Founder and Medical Director of the Centre for Digestive Diseases in Australia. Personal interview. Oct. 26, 2012.
- Borody, Thomas. "Treatment of Gastrointestinal Disorders with a Fecal Composition or a Composition of Bacteroides and E. coli." U.S. Patent Number 5,443,826. Aug. 22, 1995. (Oct. 29, 2012) http://www.google.com/patents/US5443826
- Borody, Thomas, et al. "Treatment of Ulcerative Colitis Using Fecal Bacteriotherapy." Journal of Clinical Gastroenterology. Vol. 37, no. 1. Page 42. 2003. (Nov. 1, 2012) http://prdupl02.ynet.co.il/ForumFiles_2/28701499.pdf
- Brandt, Lawrence. Professor, Department of Medicine (Gastroenterology & Liver Diseases), Albert Einstein College of Medicine. Personal interview. Oct. 28, 2012.
- Brandt, Lawrence, et al. "Long-Term Follow-Up of Colonoscopic Fecal Microbiota Transplant for Recurrent Clostridium difficile Infection." The American Journal of Gastroenterology. Vol. 107. Page 1079. July 2012. (Oct. 29, 2012) http://www.nature.com/ajg/journal/v107/n7/full/ajg201260a.html
- Centers for Disease Control and Prevention (CDC). "Deaths from gastroenteritis double." Press release. March 14, 2012. (Nov. 9, 2012) http://www.cdc.gov/media/releases/2012/p0314_gastroenteritis.html
- Centers for Disease Control and Prevention (CDC). "Inflammatory Bowel Disease (IBD)." July 15, 2011. (Oct. 30, 2012) http://www.cdc.gov/ibd/
- Centers for Disease Control and Prevention (CDC). "Methicillin-resistant Staphylococcus Aureus (MRSA) Infections." April 15, 2011. (Oct. 29, 2012) http://www.cdc.gov/mrsa/
- Eiseman, Ben, et al. "Fecal Enema as an Adjunct in the Treatment of Pseudomembranous Enterocolitis." Surgery. Vol. 44. Page 854. 1958.
- Encyclopedia Britannica. "Coprophagy." (Nov. 1, 2012) http://www.britannica.com/EBchecked/topic/136902/coprophagy
- Farquhar, James, Huiming Bao and Mark Thiemens. "Atmospheric Influence of Earth's Earliest Sulfur Cycle." Science. Vol. 289, no. 5480. Page. 756. Aug. 4, 2000.
- Floch, Martin. Assistant Clinical Professor of Medicine (Digestive Diseases) at the Yale School of Medicine. Personal correspondence. Oct. 26, 2012.
- Gewirtz, Andrew. Professor, Center for Inflammation, Immunity & Infection, Georgia State University. Personal correspondence. Oct. 29, 2012.
- Gewirtz, Andrew. "Fecal Transplant Helps Pre-Diabetics." ABC News. Sept. 22, 2010. (Oct. 29, 2012) http://abcnews.go.com/Health/video/fecal-transplant-helps-pre-diabetics-11698260
- Grady, Denise. "Gut Infections are Growing More Lethal." The New York Times. March 19, 2012. (Nov. 1, 2012) http://www.nytimes.com/2012/03/20/health/gut-infections-are-growing-much-more-lethal.html?pagewanted=all
- Hirakawa, Hirofumi. "Coprophagy in Leporids and Other Mammalian Herbivores." Mammal Review. Vol. 31, No. 1. Page 61. 2001. (Oct. 30, 2012) http://cse.ffpri.affrc.go.jp/hiroh/publications/coprophagyReview.pdf
- Hudson, William. "Little-known Fecal Transplant Cures Woman's Bacterial Infection." CNN. Sept. 27, 2012. (Oct. 30, 2012) http://www.cnn.com/2012/09/26/health/fecal-transplant/index.html
- Human Genome Project. "How Many Genes are in the Human Genome?" U.S. Department of Energy Genomic Science program. Biological and Environmental Research Information System (BERIS). Sept. 19, 2008. (Oct. 29, 2012) http://www.ornl.gov/sci/techresources/Human_Genome/faq/genenumber.shtml
- Human Microbiome Project. "Impacts on Health." NIH. (Oct. 29, 2012) http://www.hmpdacc.org/impacts_health/impact_health.php
- Human Microbiome Project Consortium. "A Framework for Human Microbiome Research." Nature. Vol. 486. Page 215. June 14, 2012. (Oct. 30, 2012) http://www.nature.com/nature/journal/v486/n7402/full/nature11209.html
- Hunt, Katherine, et al. "Characterization of the Diversity and Temporal Stability of Bacterial Communities in Human Milk." PLoS ONE. Vol. 6, no. 6. June 2011. (Oct. 29, 2012) http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0021313
- Ingham, Elaine. "Chapter 3: Bacteria." National Resource Conservation Service. (Nov. 1, 2012) http://urbanext.illinois.edu/soil/SoilBiology/bacteria.htm
- Khoruts, Alexander. Associate Professor of Medicine at University of Minnesota, Division of Gastroenterology. Personal correspondence. Oct. 26 - 27, 2012.
- Mayo Clinic. "C. difficile." Nov. 3, 2010. (Oct. 30, 2012) http://www.mayoclinic.com/health/c-difficile/DS00736
- McKenna, Maryn. "Fecal Transplants: They Work, the Regulations Don't." Wired. Dec. 9, 2011. (Nov. 1, 2012) http://www.wired.com/wiredscience/2011/12/fecal-transplants-work/
- Olszak, Torsten, et al. "Microbial Exposure During Early Life Has Persistent Effects on Natural Killer T Cell Function." Science. Vol. 336. Page 489. April 27, 2012. (Oct. 29, 2012) http://bms.ucsf.edu/sites/ucsf-bms.ixm.ca/files/20121004.bradford.emily_.pdf
- Reibman, Joan, et al. "Asthma is Inversely Associated with Helicobacter Pylori Status in an Urban Population." PLoS ONE. Vol. 3, no. 12. December 2008. (Oct. 30, 2012) http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0004060
- The Saylor Foundation. "Comparison of Digestive Systems." (Oct. 29, 2012) http://www.saylor.org/site/wp-content/uploads/2012/07/BIO309-OC-3.8.1-Comparison-of-Digestive-Systems-FINAL.pdf
- Silverman, Michael, Ian Davis and Dylan Pillai. "Success of Self-Administered Home Fecal Transplantation for Chronic Clostridium difﬁcile Infection." Clinical Gastroenterology and Hepatology. Vol. 8, no. 5. Page 471. 2010. (Nov. 1, 2012) http://crohnsend.com/documents/dr_silverman_home_transplants.pdf
- Stein, Rob. "'Gut Bug' Transplants Tested for Many Conditions." Washington Post. Sept. 24, 2011. (Oct. 30, 2012) http://www.washingtonpost.com/national/health-science/doctors-note-success-with-fecal-transplants/2011/09/24/gIQA55quYL_story.html
- Strachan, David. "Family Size, Infection and Atopy: The First Decade of the 'Hygiene Hypothesis.'" Thorax. Vol. 55, suppl. 1. Page S2. 2000. (Oct. 29, 2012) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1765943/pdf/v055p000S2.pdf
- Willyard, Cassandra. "Gut Infection Helped by Fecal Transplant." Los Angeles Times. Sept. 13, 2012. (Oct. 30, 2012) http://articles.latimes.com/2012/sep/13/health/la-he-gut-research-fecal-transplant-20120913
- Zimmer, Carl. "How Microbes Defend and Define Us." The New York Times. July 12, 2010. (Oct. 29, 2012) http://www.nytimes.com/2010/07/13/science/13micro.html?pagewanted=all
- Zimmer, Carl. "Our Microbiomes, Ourselves." The New York Times. Dec. 3, 2011. (Oct. 29, 2012) http://www.nytimes.com/2011/12/04/opinion/sunday/our-microbiomes-ourselves.html
- Zimmer, Carl. "Tending the Body's Microbial Garden." The New York Times. June 18, 2012. (Oct. 29, 2012) http://www.nytimes.com/2012/06/19/science/studies-of-human-microbiome-yield-new-insights.html?pagewanted=all&_r=0
- Zivkovic, Angela, et al. "Human Milk Glycobiome and its Impact on the Infant Gastrointestinal Microbiota." PNAS. Vol. 108, suppl. 1. Page 4653. March 15, 2011. (Nov. 1, 2012) http://stm.sciencemag.org/content/4/137/137rv5