I don’t mean to brag, but I’ve got irritable bowel syndrome, says a character of a sitcom, in the episode aired a few years ago. Irritable bowel syndrome, also known as IBS, used to be a rare condition, but - due to industrialization and urbanization - it is now one of the most common disorders in the world. The term is even used figuratively, in a derogatory sense. 

The numbers of new reported cases of irritable bowel syndrome (IBS) kept increasing into the 21st century when they reached almost epidemic proportions. As the amount of information available on the Internet exploded, so did the web searches about IBS.  But then the disorder "came out of the closet", and google searches for "irritable bowel syndrome" started to dwindle, reaching a quarter of what they used to be at the peak. This downtrend mirrored ambulatory data (National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey) showing that by 2010, the rate of IBS-related visits decreased roughly by 37%.

​Is IBS no longer a problem?

Online health communities, blogs and social networks have, over the years, changed the relationship between sufferers of IBS (and many other conditions) and their doctors. Clinical practice shifted from treatment to self-management and from medical specialists (secondary care) to primary care physicians and ‘expert patients’.

10-20 years ago, doctors were experimenting with many different medications to address IBS complaints (especially medicines used to alleviate depression and supplement fiber), but now they are more likely to prescribe non-medication therapies: diet/nutrition counseling, mental health counseling, and/or stress management. Among prescribed medications, there was increased use of gastrointestinal-specific antibiotics and probiotics, but also laxatives, proton pump inhibitors (for heartburn), antiemetics (against nausea), bile acid sequestrants (for diarrhea), opioid and non-opioid analgesics (p=0.001 for each). Prescription of fiber (p=0.001), antidepressants (p=0.002), antacids (p=0.010), and histamine-2 receptor antagonists (p=0.001) significantly decreased. 

Modern IBS patient is more informed. Modern doctors know more about IBS. They know it's not in your head and even started suggesting this is a disease, not a syndrome. But diagnostic tests confirming IBS are still lacking and so are answers to many questions.

As interest in ambulatory care for IBS was dropping, diets reducing IBS symptoms started to explode in popularity. So that sufferers of IBS-related symptoms have been even outpaced by the growing numbers of people following these trendy diets.

Gluten-free has been one of the biggest diet trends that made social events much less isolating for IBS sufferers with gluten and wheat sensitivities. Low sugar and Paleo were also helpful to many.  But low FODMAP diet seemed to be most beneficial for IBS. Yet, even this diet might not be a cure-all for IBS and can't be recommended in the longer term.

While there are dietary and stress management approaches along with a few drugs that can be used to treat IBS, what works best is when the sufferer can find a pattern of when their disease is at its worst, and can figure out ways to avoid these conditions. 

Social support is another important factor. Analyses indicated that it reduces severity of IBS symptoms, suggesting that the mechanism by which social support alleviates pain is through a reduction in stress levels.

And so IBS sufferers keep joining online support groups.  In the last 5 years, IBSgroup.org got 25 thousand more sign ups, growing from 41 to over 66 thousands. New IBS support groups on Facebook merged, some as large as 11 thousand members. Yet, as a new US survey reveals, IBS sufferers see healthcare providers and the public in general lacking in empathy and understanding. The condition is still difficult to diagnose and often even more difficult to treat.

Afraid no more, but still in search of empathy and cures.

REFERENCES

Mark Pimentel's Reddit Science AMA 2016
Health Union's “IBS in America” survey 2016

The downtown, aka our gut, is populated by microbes of many different classes with a wide variety of divergent roles. These microbes can manipulate our mind, making us hungry or full, regulating our glucose, hormones and metabolism, digesting our carbs into additional nutrients and synthesizing vitamins. 

Similarly to skilled immigrants able to strengthen economy of the city, transfer of gut microbes from lean to obese individuals could potentially transform the management of obesity. The devil is in the details, however, and we still have a lot to learn before developing such therapies, including the ability to match donors and recipients. 

Single-strain probiotics might work better than some multi-strain compositions. But developing microbiome-based remedies is more complicated than picking one type of bacteria or compiling a small list of "good microbes" and slightly tweaking it from person to person. Even for mice whose weight gain and loss patterns are much simpler than human, transfer of 39 types of microbes from lean to obese organisms did not help, but expanding it to 54 did the trick.

What are some of the microbes that make us fat and thin? ​

Four races - aka bacterial phyla Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria  - account for the majority of bacterial nations present in the human gut (Khanna and Tosh, 2014). Typically ~60% of the bacteria present in the human gut are either gram positive Bacteroidetes or gram negative Firmicutes (2005). Other major groups - Actinobacteria and Proteobacteria - can be substantially more abundant in cases like inflammatory bowel disease.  The gut microbial composition is distinctive in obese individuals and is associated with reduced numbers of Bacteroidetes and increased numbers of Firmicutes, in mice (2005) and in humans (2011, 2012). These changes have significant implications for energy homeostasis, as a 20% increase in Firmicutes and a corresponding 20% decrease in Bacteroidetes is estimated to provide an additional 150 kcal of energy per day to an adult human (2011). 

But losing weight is not as easy as nourishing Bacteroidetes and eradicating Firmicutes, as each of these groups contains thousands of species with different roles in the gut. 

If you put good people in bad neighborhoods and situations, they might actually turn bad. It takes more than a few good individuals to change culture - it won't happen if they do not win the hearts and minds of most people they work with. Microbiome transplantation may lead to beneficial metabolic changes, but it could also be imprecise and risky.
​
Microbes alone won't help us lose weight without exercising and eating right, but identifying the right species and enlisting their help might make a difference, paving the way to truly personalized nutrition and weight management. ​​

REFERENCES

Vanessa K. Ridaura, Jeremiah J. Faith, Federico E. Rey, Jiye Cheng, Alexis E. Duncan, Andrew L. Kau, Nicholas W. Griffin, Vincent Lombard, Bernard Henrissat, James R. Bain, Michael J. Muehlbauer, Olga Ilkayeva, Clay F. Semenkovich, Katsuhiko Funai, David K. Hayashi, Barbara J. Lyle, Margaret C. Martini, Luke K. Ursell, Jose C. Clemente, William Van Treuren, William A. Walters, Rob Knight, Christopher B. Newgard, Andrew C. Heath, Jeffrey I. Gordon  Cultured gut microbiota from twins discordant for obesity modulate adiposity and metabolic phenotypes in mice Science. 2013 September 6; 341(6150): 10.1126/science.1241214. doi: 10.1126/science.1241214 PMCID: PMC3829625

Thilini N. Jayasinghe, Valentina Chiavaroli, David J. Holland, Wayne S. Cutfield, Justin M. O'Sullivan
Front Cell Infect Microbiol. The New Era of Treatment for Obesity and Metabolic Disorders: Evidence and Expectations for Gut Microbiome Transplantation 2016; 6: 15. Published online 2016 February 19. doi: 10.3389/fcimb.2016.00015  PMCID: PMC4759265

Karimi, Golgis et al. The anti-obesity effects of Lactobacillus casei strain Shirota versus Orlistat on high fat diet-induced obese rats. Food & Nutrition Research 2015, 59: 29273 http://dx.doi.org/10.3402/fnr.v59.29273

Million M, Thuny F, Angelakis E, Casalta JP, Giorgi R, Habib G, Raoult D. Lactobacillus reuteri and Escherichia coli in the human gut microbiota may predict weight gain associated with vancomycin treatment.Nutr Diabetes. 2013;3:e87.

Armougom F, Henry M, Vialettes B, Raccah D, Raoult D. Monitoring bacterial community of human gut microbiota reveals an increase in Lactobacillus in obese patients and Methanogens in anorexic patients. PLoS One. 2009;4:e7125.

Million M, Angelakis E, Paul M, Armougom F, Leibovici L, Raoult D.​ Comparative meta-analysis of the effect of Lactobacillus species on weight gain in humans and animals. Microb Pathog. 2012 Aug;53(2):100-8. doi: 10.1016/j.micpath.2012.05.007. Epub 2012 May 24.

Jaclyn M. Omara, Yen-Ming Chana, Mitchell L. Jonesb, c, Satya Prakashb, c, Peter J.H. Jonesa
Lactobacillus fermentum and Lactobacillus amylovorus as probiotics alter body adiposity and gut microflora in healthy persons. Journal of Functional Foods Volume 5, Issue 1, January 2013, Pages 116–123

Sanchez et al. Effect of Lactobacillus rhamnosus CGMCC1.3724 supplementation on weight loss and maintenance in obese men and women. Br J Nutr. 2014 Apr 28;111(8):1507-19. doi: 10.1017/S0007114513003875. Epub 2013 Dec 3.

Conlon, M. A., Bird, A.R. The Impact of Diet and Lifestyle on Gut Microbiota and Human Health
Nutrients. 2015 Jan; 7(1): 17–44. Published online 2014 Dec 24. doi: 10.3390/nu7010017
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Alang, N., & Kelly, C. (2015) Weight Gain After Fecal Microbiota Transplantation. Open Forum Infectious Diseases, 2(1). DOI: 10.1093/ofid/ofv004