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...

REFERENCES

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.






REFERENCES

  • 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




Saturday, November 12, 2011

Adding red to your diet

We are always happy receiving nice e-mails from users. Here is a recent letter:


Dear Aurametrix,

I would like to share with you some interesting results that really surprised me, even though they're a little embarrassing. 

I've been using Aurametrix now about 2 months but mostly on days when I experience a symptom (2 entries for diarrhea).  So about 20 entries in all, including food, a few feeling good plus these symptoms:

Diarrhea, experienced 1 bout around 2:30 PM PDT on September 18, 2011 

Diarrhea, experienced 1 bout around 3:30 PM PDT on October 30, 2011


I did an analysis on the second day: Diarrhea relative to Feeling Good, 12 hours 
These are the results copied from the tool:


Based on your Aura entries, the following may be contributing to "Diarrhea" in a 12 hour timeframe:
  • Lycopene (when consumed more than 5.9 micrograms, up to 2650.6)
  • Orange or Yellow fruits and veggies (when consumed more than 0.1 foods, up to 1.0)
I looked up lycopene and it's a chemical in orange-colored fruits. It so happens that I ate mango one day and a raw papaya on the other day I experienced the symptoms. I think I will avoid these fruits in the future (I haven't had any since I learned about it from Aurametrix)

You can post this if you want since I think it's worthwhile to let other people know that the tool really works and I don't have symptoms.
Regards,
Aurametrix User :)

Lycopene is a carotenoid, a pigment that gives fruits and vegetables a red color. It is found in some red, pink, orange and yellow fruits and vegetables such as tomatoes (especially skins), watermelons, grapefruits, apricots, papayas, and guavas.

Lycopene is an antioxidant, but in the human body it converts into lycopenoids with the help of carotenoid monooxygenase (CMO) enzymes. Lycopene metabolism depends on the person. It is more efficient in those with more active CMOs, higher testosteron and those not restricting dietary intake.

A number of studies have suggested that a higher intake of lycopene-containing foods decreases the risk of heart disease, prostate cancer, other cancers and infections, even cataracts and asthma. Lycopene is thought to prevent male infertility, osteoporosis, varicose veins and eye disease. Lycopene may also reduce or prevent the side effects of chemotherapy.

What are the potential side effects? In one Mayo Clinic study (Jatoi et al, 2007), the most common side effect for patients who took 15,000 micrograms of lycopene twice per day was diarrhea (41% of patients), followed by nausea (26%), abdominal distension (17%), and flatulence (4%).


The same effects were also observed by IBS sufferers - like this case of massive diarrhea from fresh tomato on a sandwich or this bad gut reaction to tomato sauce. Mangoes and Papayas are usually considered safe for IBS, yet occasional incidents are posted on the web.

So, should you limit your Lycopene intake if Aurametrix indicates it may cause your diarrhea? Take a note about it and keep analyzing your diet. Analyses that start from "Aura entries" examine food combinations and will tell you if there is something that negates the effect. Perhaps there was a day when you ate it and felt OK. You might not remember it, but Aurametrix will.


REFERENCES

Jatoi A, Burch P, Hillman D, Vanyo JM, Dakhil S, Nikcevich D, Rowland K, Morton R, Flynn PJ, Young C, Tan W, & North Central Cancer Treatment Group (2007). A tomato-based, lycopene-containing intervention for androgen-independent prostate cancer: results of a Phase II study from the North Central Cancer Treatment Group. Urology, 69 (2), 289-94 PMID: 17320666.

Kelkel M, Schumacher M, Dicato M, Diederich M. (2011) Antioxidant and anti-proliferative properties of lycopene. Free Radic Res. 2011 Aug;45(8):925-40. Epub 2011 May 26.

Brian L. Lindshield, Kirstie Canene-Adams, John W. Erdman Jr (2007) Lycopenoids: Are lycopene metabolites bioactive? Archives of Biochemistry and Biophysics. Volume 458, Issue 2, Pages 136-140.

Sunday, August 14, 2011

Hold the Starch?


Starch is that stuff that stiffens your shirts. It's also what most people eat for fuel. Wheat, rice, corn, oats, potatoes are all very starchy foods. Many popular diet plans call starch a second-rate food that should be avoided at all costs. No-starch and low starch diets are favored by irritable bowel communities, while former Weight Watchers, Jenny Craig and Atkins enthusiasts love the new Carb Lovers Diet praising starch. Yet, there may be something good about starch even for those with sensitive stomachs. 


Starch is a mixture of long and intermingled molecules digested with different rates and outcomes. Our bodies' response to eating starch depends on its amount and types along with our nature [1] and nurture, including intestinal microbes eating the leftovers [2].


Resistant Starch (RS), also called Functional Fiber, is a type of starch that may have beneficial physiological effects. It is further classified into four or five classes,  like RS2 in potatoes or RS3 (maltodextrin on food labels) formed when starchy foods are cooked and cooled. Resistant starch is not digested in the small intestine of healthy individuals. It is an effective prebiotic as it feeds and stimulates specific bacteria in the gut [3]. Bacteria consuming resistant starch raise levels of short-chain fatty acids (SCFA) and derivatives that can act as a source of energy [2,4] and provide other benefits like protection from inflammatory conditions of the bowel. 


Over 200 nutritional studies showed  that resistant starch increases satiety, reduces food consumption and can prevent weight regain, acting almost like exercise. It also lowered insulin levels and reduced the deposition of fat.

How much resistant starch do we need to eat?

Adults in most developed countries consume between 3-7 grams of resistant starch per day. The Carb lovers diet recommends 10-15 grams. According to an earlier Australian study [5], 20 grams per day may be even more beneficial. However, optimal levels of resistant starch in diet are very individual, depending on body weight, metabolism, microbial makeup and dietary preferences. Flatulence and belching are among potential side effects.

Resistant starch is like other types of fiber and prebiotics – everybody has their own individual threshold and every extra gram leads to production of excessive gas [6].
Fructooligosaccharides (FOS) and inulin, prebiotics selectively stimulating bacteria in the colon, usually lead to mild flatulence starting from about 10 grams per day. Isolated individuals experience discomfort even at 5 grams. 14-15 grams per day usually mark the threshold for significant increase in flatulence, stomach growling and cramping. Resistant starch may have slightly higher sensitivity thresholds [6].



Source
Total starch,  per 100 g
  Resistant starch, per 100 g
Lentils
53.3
25.4
Red kidney beans
42.6
24.6
Black-eyed peas
53.9
17.7
Potato chips
29.5
4.8
Long-grained rice, parboiled
25
3.7
Spaghetti, cooked for 9 mins
22
2.9
Mashed potatoes
8.5
2.4
Boiled potatoes
15
2
White bread
46.7
1.9
Rye crisps
67.4
1.4
Puffed wheat cereal
67
1.2
Medium-grained rice, boiled
25
0.6
Spaghetti, cooked for 12 mins
22
0.9
Oatmeal (Oat porridge)
9
0.3


Understanding what amounts are right for you takes careful analysis and evaluation  Don’t forget about the digestible starch that accompanies indigestible starch. Ideally, our enzymes can efficiently break down the digestible starch into glucose, but the process is so lengthy (5-7 hours) that overload could result in more starch leaking through pores in the small intestine before it has a chance to be digested. This leads to endotoxins and an excess of methane and carbon dioxide, in addition to other metabolic end products, in your system.  

So remember:  there are different types of starch and they usually come packaged with other food components for which you might have separate sensitivities. In other words, your mileage may vary.


REFERENCES


[1] Perry GH, Dominy NJ, Claw KG, Lee AS, Fiegler H, Redon R, Werner J, Villanea FA, Mountain JL, Misra R, Carter NP, Lee C, Stone AC.   Diet and the evolution of human amylase copy number variation. Nat Genet. 2007 Oct;39(10):1256-60. Epub 2007 Sep 9.


[2] Bird AR, Conlon MA, Christophersen CT, & Topping DL (2010). Resistant starch, large bowel fermentation and a broader perspective of prebiotics and probiotics. Beneficial microbes, 1 (4), 423-31 PMID: 21831780


[3] Gray, G. Dietary fibre – from definitions to public health messages (pages 159–161). Article first published online: 13 Aug 2008 | DOI: 10.1111/j.1467-3010.2008.00702

[4] Donohoe, DR, Garge, N, Zhang, X, Sun, W, O'Connell, TM, Bunger, MK, Bultman, SJ. (2011). The Microbiome and Butyrate Regulate Energy Metabolism and Autophagy in the Mammalian Colon. Cell Metabolism 13 (5): 517–26

[5] Baghurst PA, Baghurst KI, Record SJ, Dietary fibre, non-starch polysaccharides and resistant starch – a review. Food Australia, 1996 Vol 48, No. 3:S1-S35.

[6] Brighenti F, Pellegrini N, Casiraghi MC, Testolin G (1995) In vitro studies to predict physiological effects of dietary fibre. European Journal of Clinical Nutrition 49, Suppl. 3, S81±S88

[7] Elmståhl, L.H. Resistant starch content in a selection of starchy foods on the Swedish market. European journal of clinical nutrition: 2002 Jun;56(6):500-5.

Monday, May 30, 2011

Tryptophan in food: Will it make you happy, sleepy or smelly?

And the answer is ... either or all of the above. And this is not a complete list of all that can happen. In some rare conditions, for example, tryptophan could also make your pee purple.


Tryptophan supplements were used as a popular sleeping aid until
negative press in 1989. The FDA banned dietary tryptophan supplements from the market, just days before the arrival of Prozac rising as the new promise for chemical happiness. Further investigation showed that ill effects of tryptophan were actually due to a contaminant in the supplement not the amino acid itself.
Today you can find tryptophan at many supplement retailers. You can also get it from food - from chocolate or red meat, for example. What does it really do in our bodies?

Tryptophan is a complex aromatic amino acid  - one of eight "essential" amino acids that have to be taken with food as they cannot be created by the human body. Tryptophan metabolism is complex - KEGG pathway shows the multitude of reactions it participates in.
One of tryptophan metabolites - Kynurenic acid - is involved in the regulatory function of the gastrointestinal system and the modulation of the inflammatory response. Another metabolite is neurotransmitter Serotonin which has a calming and sleeping-inducing effect on the brain.
L-Tryptophan administration (2 g) as a single dose before a meal has been found to decrease subjective hunger ratings, food intake, and alertness in men (Hrboticky et al., 1985), but not women (Leiter et al., 1987).  Babies  were also found to get sleepier (20 mg supplementation, Yogman and Zeisel, 1983, 1985). Tryptophan can be used by the body to create 5-hydroxytryptophan (also known as 5-HTP and oxitriptan). 5-HTP is sold as a dietary supplement as an antidepressant and sleep aid. It is marketed under many different trade names such as Cincofarm, Levothym, Oxyfan and Triptum.  Studies showed that 5-HTP provides benefits with regard to depression, blood pressure and regular sleep patterns. So even though that fact that the Thanksgiving turkey is responsible for sleepiness is an urban legend, tryptophan could definitely contribute to calmness and happiness.

Yet, according to a study by British researchers, irritable bowel syndrome sufferers have an increase in gastrointestinal symptoms after ingestion of a large dose of tryptophan, in addition to having fewer symptoms of anxiety and depression. One of the reasons: tryptophan metabolism mostly happening along the kynurenine and not 5-HT pathway. Increased tryptophan catabolism was recently shown to be associated with depression, reduced motivation and pessimism in the elderly. According to earlier studies (like the referenced 1998 articles by Austrian scientists), people with fructose malabsorption have abnormal tryptophan metabolism too, leaving them with less available tryptophan, and it seems to be responsible for mental depression (Ledochowski et al., 1998).   Overdose of tryptophan  in healthy adults (5 g in a double-blind, placebo-controlled study) induced  severe nausea and headache and increased drowsiness soon after ingestion (Greenwood et al., 1975). 
What happens to tryptophan abnormally accumulated in intestines? Here come more bad news - it is utilized by intestinal bacteria (e.g. Lactobacillus) and converted into indole and skatole - metabolites responsible for strong fecal smell. The rate of production of these smelly compounds depends on the acidity  - it is greatest at pH 6.5 and less at pH 5.0 and 8.0. Food-food interaction could lessen or enhance the "smelly"effects. The suppression of tryptophan degradation by propolis, for example,  could contribute to beneficial health properties. Preliminary results were also reported for cocoa extracts, Fructooligosacharides (FOS) and resistant starch, but more studies are needed.

So, how much tryptophan do you really need?  Half a gram, 2 grams, even more? It depends on your metabolism, your life style and your diet. It may be a good idea to watch your wellbeing along with tryptophan intake, to find your own optimal daily value.
This post was chosen as an Editor's Selection for ResearchBlogging.org



REFERENCES

Capuron L, Schroecksnadel S, Féart C, Aubert A, Higueret D, Barberger-Gateau P, Layé S, & Fuchs D (2011). Chronic Low-Grade Inflammation in Elderly Persons Is Associated with Altered Tryptophan and Tyrosine Metabolism: Role in Neuropsychiatric Symptoms. Biological psychiatry PMID: 21277567

Christmas DM; Badawy AAB; Hince D; Davies SJC; Probert C; Creed T; Smithson J; Afzal M; et al. (Oct 2010). Increased serum free tryptophan in patients with diarrhea-predominant irritable bowel syndrome. NUTR RES. 30:678-688. DOI.

Hood SD; Hince DA; Davies SJC; Argyropoulos S; Robinson H; Potokar J; Nutt DJ. (Feb 2010). Effects of acute tryptophan depletion in serotonin reuptake inhibitor-remitted patients with generalized anxiety disorder. PSYCHOPHARMACOLOGY. 208:223-232. DOI.

Shufflebotham J; Hood S; Hendry J; Hince DA; Morris K; Nutt D; Probert C; Potokar J. (Nov 2006). Acute tryptophan depletion alters gastrointestinal and anxiety symptoms in irritable bowel syndrome. Am J Gastroenterol. 101:2582-2587. DOI.

Ledochowski M, Widner B, Murr C, Sperner-Unterweger B, Fuchs D. Fructose malabsorption is associated with decreased plasma tryptophan. Scand J Gastroenterol. 2001 Apr;36(4):367-71.

Ledochowski M, Sperner-Unterweger B, Widner B, Fuchs D. Fructose malabsorption is associated with early signs of mental depression. Eur J Med Res. 1998 Jun 17;3(6):295-8.

Xu ZR, Hu CH, Wang MQ. Effects of fructooligosaccharide on conversion of L-tryptophan to skatole and indole by mixed populations of pig fecal bacteria. J Gen Appl Microbiol. 2002 Apr;48(2):83-90.

Jones HE, Johnson RE, Bigelow GE, Silverman K, Mudric T, Strain EC. Safety and efficacy of L-tryptophan and behavioral incentives for treatment of cocaine dependence: a randomized clinical trial. Am J Addict. 2004 Oct-Dec;13(5):421-37. 

Jensen MT, Cox RP, Jensen BB. 3- Methylindole (skatole) and indole production by mixed population of pig fecal bacteria.  Appl Environ Microbiol. 1995 Aug;61(8):3180-4.


Celenza JL. Metabolism of tyrosine and tryptophan - new genes for old pathways. Curr Opin Plant Biol. 2001 Jun;4(3):234-40.