Monday, December 24, 2012

Molehills and Mountains

If you suffer from IBS, chances are you're very considerate of others and even possibly an anxious ''catastrophizer.'' It was repeatedly concluded based on magnetic resonance imaging of the brain and psychological questionnaires -  for students and non-students, Easterners and Westerners, right-handed and left-handed individuals. In fact, IBS sufferers' anxieties are somewhere in between those of people with Crohn's disease (similar to healthy persons) and panic patients. And many IBS sufferers are convinced that social and occupational implications of their gastrointestinal symptoms are a catastrophe.

As someone once said, catastrophizing is not just about watching slow German films or reading Russian literature and feeling as though life is an intolerable and senseless joke. If practiced properly, catastrophizing could make many things go wrong and create a reality around our worries and fears. Including fears focused on the gut. Because if you believe something will go wrong, you make it go wrong.

But is it the personality that makes us susceptible to IBS or is it IBS that changes our personality? The connection between the brain and the gut is definitely bidirectional. So this question might be a chicken-and-egg problem.

Animal studies suggest that perturbations of behavior, such as stress, can alter microbial communities in the gut. Experimental perturbation of the microbial communities, in its turn, can alter behavior. Getting rid of some microbes helped mice to reduce anxiety or even become bold and adventurous (after neomycin, bacitracin, and pimaricin antibiotics were administered to timid and shy BALB/c mice), while adding new species of bacteria such as Campylobacter jejuni  made mice more cautious.

Many recent studies indicate the possibility of discovering bacteria specific for different types of IBS. But you can make your own discoveries before science does. Such as the best diet, exercise and emotional attitude to cultivate the bacteria of success.

Your result will be the last one in the table below. It might take up to 24 hrs for it to appear so please come back to see it.
Your score is represented in three dimensions:
rumination (repetitiveness of focusing on the symptoms of distress), magnification (the degree to which you tend to magnify your symptoms) and hopelessness (the despair you feel when you have abandoned hope of comfort or success).


Hazlett-Stevens H, Craske MG, Mayer EA, et al. Prevalence of irritable bowel syndrome among university students: the roles of worry, neuroticism, anxiety sensitivity and visceral anxiety. J Psychosom Res 2003;55:501–505.

Ng SM, Chow KW. Symptoms catastrophizing versus social hypervigilance in irritable bowel syndrome patients. Soc Work Health Care. 2012;51(8):743-56. doi: 10.1080/00981389.2012.701001.

Hunt MG, Moshier S, Milonova M. Brief cognitive-behavioral internet therapy for irritable bowel syndrome. Behav Res Ther. 2009 Sep;47(9):797-802. Epub 2009 May 20.

Eric L. Garland, Susan A. Gaylord, Olafur Palsson, Keturah Faurot, J. Douglas Mann and William E. Whitehead Therapeutic mechanisms of a mindfulness-based treatment for IBS: effects on visceral sensitivity, catastrophizing, and affective processing of pain sensations. Journal of Behavioral Medicine, 2011, Dec. 8

Blankstein U, Chen J, Diamant NE, Davis KD. Altered brain structure in irritable bowel syndrome: potential contributions of pre-existing and disease-driven factors.
Gastroenterology. 2010 May;138(5):1783-9. doi: 10.1053/j.gastro.2009.12.043. Epub 2010 Jan 4.

Collins SM, Surette M, & Bercik P (2012). The interplay between the intestinal microbiota and the brain. Nature reviews. Microbiology, 10 (11), 735-42 PMID: 23000955

Neufeld KM, Kang N, Bienenstock J, Foster JA. Reduced anxiety-like behavior and central neurochemical change in germ-free mice. Neurogastroenterol Motil. 2011 Mar;23(3):255-64, e119. doi: 10.1111/j.1365-2982.2010.01620.x. Epub 2010 Nov 5.

Collins SM, Bercik P. The relationship between intestinal microbiota and the central nervous system in normal gastrointestinal function and disease. Gastroenterology. 2009 May;136(6):2003-14. doi: 10.1053/j.gastro.2009.01.075. Epub 2009 May 7.

Goehler LE, Park SM, Opitz N, Lyte M, Gaykema RP. Campylobacter jejuni infection increases anxiety-like behavior in the holeboard: possible anatomical substrates for viscerosensory modulation of exploratory behavior. Brain Behav Immun. 2008 Mar;22(3):354-66. Epub 2007 Oct 24.

Sullivan MJL, Bishop S, Pivik J. The Pain Catastrophizing scale: development and validation. Psychol Assess 1995;7:524–32. (the manual)

Sunday, August 5, 2012

Carbohydrates for your bacteria

Our bacteria are picky eaters. Some of them - like Prevotelia - prefer a high carbohydrate diet, while others - like Bacteroides - stick to unhealthy western lifestyle with lots of meat and fat. The most prevalent bacteria in the gut of horses, cows and goats prefer people consuming alcohol and polyunsaturated fats. Methanobrevibacter is most abundant in anorexic nervosa patients. Gram negative bacillus Bilophila wadsworthia loves people with gangrenous appendicitis or those whose diets are high in milk fat. The most widely promoted prebiotics inulin and fructooligosaccharides seem to attract Bifidobacteria. What about diets low in poorly absorbed fermentable carbohydrates aka FODMAPs that seem to aggravate irritable bowel syndrome (IBS) ? Which bacteria is responsible?

A recently completed clinical trial  looked at the effects of low-FODMAP dieting by analyzing Short Chain Fatty Acids (SCFA), pH and other qualities of stool.

The data show that with less FODMAPs in the diet, there seemed to be less water and fermentable substances in the proximal colon, and less gastrointestinal distress in patients with IBS. This randomized controlled trial also demonstrated a reduction in concentration and proportion of luminal bifidobacteria after 4 weeks of fermentable carbohydrate restriction.

Bifidobacteria? Isn't it one of the "friendliest" bacteria alleviating symptoms in IBS, by normalizing the ratio of an anti-inflammatory to proinflammatory cytokines? At least, as was shown for B.infanitis 35624 and B. animalis DN-173 010 in different studies. It looks like that the most effective species and the implications of diets on the gastrointestinal microbiota are still uncertain. After all, another study showed that even though IBS sufferers have lower amounts of Bifidobacteria than non-sufferers, those whose symptoms are less severe show even lower amounts of Bifidobacteria in their samples.

What can we say except that more studies are needed...


Staudacher HM, Lomer MC, Anderson JL, Barrett JS, Muir JG, Irving PM, & Whelan K (2012). Fermentable carbohydrate restriction reduces luminal bifidobacteria and gastrointestinal symptoms in patients with irritable bowel syndrome. The Journal of nutrition, 142 (8), 1510-8 PMID: 22739368

Suzanne Devkota, Yunwei Wang, Mark W. Musch, Vanessa Leone, Hannah Fehlner-Peach, Anuradha Nadimpalli, Dionysios A. Antonopoulos, Bana Jabri, Eugene B. Chang. Dietary-fat-induced taurocholic acid promotes pathobiont expansion and colitis in Il10−/− mice. Nature, 2012; DOI: 10.1038/nature11225

Cui S, & Hu Y (2012). Multistrain probiotic preparation significantly reduces symptoms of irritable bowel syndrome in a double-blind placebo-controlled study. International journal of clinical and experimental medicine, 5 (3), 238-44 PMID: 22837798

Wu GD, Chen J, Hoffmann C, Bittinger K, Chen YY, Keilbaugh SA, Bewtra M, Knights D, Walters WA, Knight R, Sinha R, Gilroy E, Gupta K, Baldassano R, Nessel L, Li H, Bushman FD, & Lewis JD (2011). Linking long-term dietary patterns with gut microbial enterotypes. Science (New York, N.Y.), 334 (6052), 105-8 PMID: 21885731

O'Mahony L, McCarthy J, Kelly P, Hurley G, Luo F, Chen K, O'Sullivan GC, Kiely B, Collins JK, Shanahan F, Quigley EM. Lactobacillus and bifidobacterium in irritable bowel syndrome: symptom responses and relationship to cytokine profiles. Gastroenterology. 2005 Mar;128(3):541-51.

Monday, May 7, 2012

Finding the Goldilocks Solution

A top story in today’s news is related to a recent scientific paper published in Current Biology concerning the dinosaurs. British scientists wanted to know, Could methane produced by sauropod dinosaurs have helped drive Mesozoic climate warmth?  By their estimates, some 520 million tons of methane (a “greenhouse gas” emission) were produced by the flatulent beasts every year.  This begs the question, do flatulent humans today also contribute to global warming?

Probably not enough to be concerned about. Even so, this doesn’t allay the anxieties people have about expulsing gas—anxieties that have more to do with interpersonal relationships in the workplace than with the implications of global warming.

As Dr. Wynne-Jones says in an article on diverticular disease, many bowel-related problems are in fact confined to modern urban communities affecting “the cultured, the refined, the considerate.” Folks go out of their way to avoid beans in their diet for fear of embarrassing themselves in a working environment where everyone is packed together in neighboring cubicles.

Happily, Winham  and  Hutchins discovered that over 50% of people can consume up to ½ cup of beans daily without any adverse effects. But how do you know how much beans to eat on your own?  How do you arrive at the Goldilocks amount—not too much, not too little—that’s just right for you?

Personal health analysis tools like Aurametrix are already making it possible to apply systematic measures to discover for ourselves our individual tolerance levels for a wide variety of foods. As Aurametrix founder Irene Gabashvili remarked in her Forbes article:  “A digital nurse can analyze hundreds of ‘health variables’ in search of patterns in the data. She could do this with far greater precision than a physician or nutritionist, due to her ability to quickly and tirelessly check all possible combinations. In a relatively short timeframe she could narrow down the factors that are positively and negatively influencing your health, while taking into consideration your pre-existing conditions and sensitivities.”

To see the digital nurse in action, see the video below. It shows how to pin-point the causes of a related, though potentially embarrassing, physiological process: frequent stomach growling.


  • Wilkinson, D., Nisbet, E., & Ruxton, G. (2012). Could methane produced by sauropod dinosaurs have helped drive Mesozoic climate warmth? Current Biology, 22 (9) DOI: 10.1016/j.cub.2012.03.042 
  • Winham DM, & Hutchins AM (2011). Perceptions of flatulence from bean consumption among adults in 3 feeding studies. Nutrition journal, 10 PMID: 22104320
  • Wynne-Jones, G. (1975) Flatus retention is the major factor in diverticular disease. The Lancet, 306 (7927), 211 - 212, doi:10.1016/S0140-6736(75)90677-7