Talk:Helicobacter pylori

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Contents 1 Acid good or bad? 2 Honey treatment research 3 References 3.1 Organisms in the stomach 3.2 Weird ungrammaticality in "Infection and Diagnosis" 4 Microaerophilic 5 taxobox 6 Broccoli 7 MALT lymphoma 8 Barry Marshall on this page 9 Harvard referencing 10 Bacillus 11 Featured on biology portal 12 Version 0.5 nomination failed 13 Molecular hydrogen is the energy source 14 Thomas Borody 15 spontaneous elimination 16 Virulence factors 17 Conversion of urea into ammonia and bicarbonate 18 Role of pyrogenic (inflammatory) factors in invasion 19 Role in gastric cancer

[edit] Acid good or bad?

The article states that before ulcers were known to be caused by bacteria, they were treated by medications which reduced stomach acid. But it also states that the bacteria itself releases enzymes to reduce stomach acid, to make its environment more hospitable to it. So is stomach acid helpful or harmful to the bacteria? 66.81.100.52 20:27, 30 August 2005 (UTC)

The levels of acidity that can be produced in the human stomach can be harmful to bacteria such as Helicobacter pylori, but Helicobacter pylori has mechanisms that protect it fromthe harsh acidic environment of the stomach. Once the stomach has been damaged (ulcer), the damaged tissue is itself less well protected against stomach acid, reducing acid production can help the ulcer to heal. --JWSchmidt 21:49, 30 August 2005 (UTC)

But presumably, even in the presence of an ulcer, the stomach acid is serving a purpose: to keep the H pylori population in check (its limited tolerance for acidic conditions notwithstanding), and in doing so prevent further ulcers from forming, which would happen if H pylori were allowed to reproduce and attack the stomach lining more heavily. So I still don't understand why intervening to decrease stomach acid is a good idea. It sounds like there should be a more detailed explanation. A5 05:36, 6 September 2005 (UTC)

H. pylori is not a thrifty organism and does not prolifically reproduce under any known circumstances. Temporarily reducing production of stomach acid helps ulcers heal to a degree largely without affecting H. pylori growth, as far as I know. --Bk0 (Talk) 19:25, 25 December 2005 (UTC)

It is thought that immune cell infiltration below the stomach epithelia may play some part in ulcer formation; H. pylori is thought to enhance inflamatory vs. antibody immune response (at least in some strains). Immune cell infiltration is, in fact, noted in even asymptomatic infection. Also, H. pylori is not particularly acid tolerant (the gastric mucosa being near neutral pH), and prolifically is very relative (it's doubling time is much faster than M. tuberculosis for example), and compare thrifty to some sucessful obligate intracellular organisms.

The gastric mucosa protects the stomach from the harsh environment it generates. An ulcer is essentially a wound to the stomach in which the mucosa can not protect as effectivley. Thus, reducing stomach acid helps the wound to heal.

[edit] Honey treatment research

As for as I can tell, the external link to Honey Research Around the World leads to two relevant abstracts and this article: Causes of the antimicrobial activity of honey.

One of the two abstracts seems never to have led to a full publication. The other seems to have been followed up by: Osmotic effect of honey on growth and viability of Helicobacter pylori.

This is another reference for the action of honey on H. pylori: Susceptibility of Helicobacter pylori to the antibacterial activity of manuka honey.

It might be useful to have a section for research on non-antibiotic treatments for H. pylori. Unfortunately, this 2003 review indicates that no clinical trials for alternative therapies have shown positive results.

• Removed the external link on honey research as they are all 5-10 years old (1994-1999) and recent treatment guidelines do not mention them. The lastest link from Helicobacter journal Aug 2004 - The Year in Helicobacter pylori 2004 in the chapter Therapy of Helicobacter pylori under Novel agents does include this "Bee glue propolis, has antimicrobial and anti-inflammatory effects and in vitro studies have shown its effectiveness in inhibiting H. pylori." [1] Other novel agents are also listed in the journal article include ginger root and essential oils. Petersam 08:22, 22 Dec 2004 (UTC)

Important distinction, most alternative treatments including honey and gum are all in-vitro, which falls short of even Marshall's one man experiment. GraemeLeggett 11:32, 18 Feb 2005 (UTC)

[edit] References

The above linked site offers a wealth of information that could really help to solidify this article and make it more accurate and reliable. It is to available text of the journal Helicobacter pylori and has potentially better information than the 1994 NIH study. Specifically one of the articles has actual risk factor statistics for the increase in gastric cancer due to H. pylori. I am unfortunately not in the position to understand the details of the subject, so hopefully someone that is can make use of the articles from the above link to improve the article and its citation. - Taxman 23:43, Dec 22, 2004 (UTC)

As a side note, does anyone know about the prestige of the Helicobacter pylori journal or its peer review practices? - Taxman 23:43, Dec 22, 2004 (UTC)

I will do a Pubmed search and filter some useful references. The original discovery of the bug in the early 1980s will need to be refenced. As for the H. Pylori journal, this is a typical niche journal. The really relevant studies will have been published in the big core journals like The Lancet, NEJM, JAMA or the BMJ, or the core specialist journals (Am J Gastroenterol & Gut). JFW | T@lk 08:26, 23 Dec 2004 (UTC)

Go to GUT for that Journal GraemeLeggett 11:02, 18 Feb 2005 (UTC)

[edit] Organisms in the stomach

I have changed the text to show that Heicobacter thrives in the stomach rather than survives. Many organisism suvive a transit of the stomach including many bacteria and protozoan spores, Cryptospoidium, Giardia etc, many viruses, some parasitic platyhelminths, flukes, tape-worms, prions etc. I am also concerned about the authority for the statement that it "....can literally screw itself into the stomach lining." This implies some form of active burrowing activity which is not a characteristic of other helical bacteria. Is this referenced authoritatively somewhere ? It is probably also incorrect to refer to 'poor' people at being at highest risk. The epidemiology shows that affluent young Caucasions in the English speaking world are least at risk , but that doesn't equate to rich and poor. It is more a reflection of local customs and habits with the low incidence group adopting life-styles based on high standards of cleanliness and hygiene. Other life-styles may provide different but equally worth-while benefits not enjoyed by young white Americans.
Velela 13:27, 2 Mar 2005 (UTC)

Hp is a very active bacteria, those flagella do thrust it along. The stomach lining is question is the mucus layer rather than the flesh. GraemeLeggett 13:32, 2 Mar 2005 (UTC)

[edit] Weird ungrammaticality in "Infection and Diagnosis"

In er March 2nd edit, Velela deleted part of the sentence "Under poor sanitary conditions...", so that it is now ungrammatical; this change persisted subsequent edits. I about to edit it back, so that it is grammatical. I claim no knowledge of the subject material, and so hope that someone who is expert will audit this semi-reversion (semi- because this was not Velela's entire edit). --jholman 06:09, 26 Mar 2005 (UTC)

[edit] Microaerophilic

Does this term derive from aerophilism- an organism that can live in an enviroment that has extremly limited oxygen content? What is the format for adding in a term like this that doesn't quite deserve a full entry? Aerophilism doesn't exist in the Extremophile article, so one might add a new stub defining that. But what about microaerophilism- how could you make a stub of a stub? Would formating the article so that microaerophilic only has 'areophilic' linked?

I suggest a link through to aerobic organism GraemeLeggett 14:15, 28 Mar 2005 (UTC)

Microaerophilic is an accepted term in microbiology. The organism can *only* live in environments in which oxygen is limited (less than atmospheric), but present. Neither atmospheric nor anaerobic conditions are accepatable.

[edit] taxobox

beautiful table

[edit] Broccoli

Broccoli works long term better than any drug-based treatment, IMHO.

The problem is that your HO needs supportive evidence before this can be mentioned in this article. If you can cite studies that compare broccoli with triple therapy, you are completely in your right to add this to the article. Otherwise, it will qualify as original research, something that's discouraged on Wikipedia. JFW | T@lk 07:30, 6 October 2005 (UTC)

Broccoli as a treatment is properly referenced in the article. My interpretation of the paper is that long term Broccoli consumption supresses H pylori activity but does not eliminate. GraemeLeggett 08:17, 6 October 2005 (UTC)

[edit] MALT lymphoma

I felt like writing up MALT lymphoma. Comments there please :-) JFW | T@lk 09:18, 12 December 2005 (UTC)

[edit] Barry Marshall on this page

Just finished watching a roundtable discussion between this years Nobel prize laureates on the BBC, and during the discussion on information technology and the effects of the internet the subject of wikipedia came up. Dr. Marshall mentioned that he and Warren had been working on H. pylori for years and even they couldn't write a better article, and generally approved of the collaborative enterprise.

Do you have any idea of when that BBC discussion was recorded? --JWSchmidt 13:52, 18 December 2005 (UTC)

Ezeu just reported that this was on "Nobel Minds", a BBC/SVT produced forum discussion program. It was hosted by Nik Gowing, taped on 9 December ([2]) and aired on 17 December. I couldn't find an online video or transcript. AxelBoldt 22:58, 18 December 2005 (UTC)

That's awesome InvictaHOG 20:11, 18 December 2005 (UTC)

You can find the video here. "Interesting part" starts around 39:45. Barry Marshalls comment is around 43:00. --Avatar 09:13, 13 November 2006 (UTC)

[edit] Harvard referencing

The Wikipedia guideline for non-numbered reference lists seems to be that the Harvard referencing system be used. I think it would be useful for the current reference list to be put in alphabetical order. --JWSchmidt 20:54, 18 December 2005 (UTC)

I personally think that numbered lists should be used when possible, but following guidelines if not makes sense - InvictaHOG 21:26, 18 December 2005 (UTC)

I think numbered references are nice because the hypertext links between citations and references in the list make it easy to keep going back-and-forth between the main text and the reference list. --JWSchmidt 02:05, 19 December 2005 (UTC)

I prefer numbered references.--FloNight 22:49, 19 December 2005 (UTC)

[edit] Bacillus

I turned the characterization as "bacillus" back into "bacterium", because we already discuss the shape of the organism, and "bacillus" unfortunately has two meanings. To call it a "bacillus" seems to confuse more than it clarifies. AxelBoldt 19:07, 25 December 2005 (UTC)

I agree. It is classified as a spirochete in some publications, and as a "spiral bacillus" in others. --DocJohnny 17:41, 26 December 2005 (UTC)

[edit] Featured on biology portal

Congratulations! This article is the current Featured article on the Biology Portal. If you would like to help with the Biology Portal the best place to start is the portal talk page. --Cyde Weys _vote^talk 00:47, 29 December 2005 (UTC)

[edit] Version 0.5 nomination failed

This article is considered to fall outside the scope of the Version 0.5 test release, since this version only includes a limited number of articles. It is now held ready for a later version such as Version 1.0 nomination. Walkerma 04:07, 5 June 2006 (UTC)

[edit] Molecular hydrogen is the energy source

Molecular hydrogen is the energy source, not hydrogen methanogenesis. H. pylori is not a methanogen. For further reference, check this article in Science about metabolism. I've corrected it to reflect that.Antorjal 23:06, 21 August 2006 (UTC)

Does it use oxygen as electron acceptor? AxelBoldt 22:30, 9 September 2006 (UTC)

[edit] Thomas Borody

Dr. Borody certainly was one of the early pioneers of Helicobacter treatment, but was he the first to eradicate Helicobacter with triple therapy? I've always been taught that it was the Amsterdam group (PMID 1971318). -- Samir धर्म 03:32, 15 September 2006 (UTC)

[edit] spontaneous elimination

Recently, a colleague of mine, Dr. Karen Goodman, one of the leading epidemiologists studying H.pylori infection, changed this entry to correct the dogma that H.p is never spontaneously eliminated. Her research, among others, provides evidence that strongly suggests there is spontaneous elimination, and it might be quite frequent, at least among children. In any case, it is clear that there is no evidence that suggests H.p infection always persists. MarcoTolo (I don't know who s/he really is) deleted Dr. Goodman's correction, without explanation. MarcoTolo also added a reference that was presumably meant to support the dogmatic claim, but actually turned out to be a non sequitur (referencing the statement "It is widely believed...." with an article from 1992 obviously does not make sense, since the statement is about contemporary beliefs and the article is not contemporary and did not address beliefs). More important, on the issue of whether there is spontaneous elimination, a 1992 paper is of interest only for historical purposes since most (arguably, all) of the relevant research has taken place since then. Thus, when I added the accurate current information back, I removed the reference.

Dr. Goodman expressed skeptism about the value of trying to improve Wikipedia when I suggested she do so, and guessed that it would never keep up with the latest research, and thus her change would be replaced with the original dogma the very next day. Since her prediction of her contribution being trashed in a day was born out, I doubt she will bother to try to correct the mistake that was reintroduced or otherwise contribute to Wikipedia again. I am going to try to prove her wrong about the potential of Wikipedia by putting the correct information back into the article, and I hope it will not again be changed by someone who is not expert on the current literature. Carlvphillips 03:28, 22 September 2006 (UTC)

• Please, by all means, update the article if you have newer information - that's what Wikipedia is all about. But (and this is an important caveat), if you're an "expert in the literature", cite the literature when you update the article rather than making blanket, unreferenced statements. In general, the "because I said so" argument plays about as well in Wikipedia as it does elsewhere in science.

A quick read through the Goodman et al paper (I'm assuming you're referring to "Dynamics of Helicobacter pylori infection in a US-Mexico cohort during the first two years of life." (Goodman et al. Int J Epidemiol. 2005 Dec;34(6):1348-55. Epub 2005 Aug 2. (PMID 16076858)) looks promising, though I'd personally caution against claiming that Goodman 2005 has completely disproven the endemic and persistent nature of H. pylori infections with a study of children birth-to-24 months. As good as the study may be, the commentary by Perry & Parsonnet (Int J Epidemiol. 2005 Dec;34(6):1356-8. Epub 2005 Nov 22.) does have some good points. -- MarcoTolo 04:00, 22 September 2006 (UTC)

Ok, I get it. Thanks. I am going to guess that Dr. Goodman's original change was deleted because she did not cite references (though I will note that most of the rest of that entire section lacks references) and (if I am understanding how this works correctly) she did not sign in, so was not identifiable. Having reread what I wrote above, I wanted to apologize for it sounding so rude -- I should have been more careful about what I was writing "sounded" and I appreciate you responding more politely than I must have seemed to you. (I will also note that I am very impressed by how quickly you found the references and digested them -- it took you less time to do that than it took me to figure out how to format them). I have added two references -- the one you cite (which I am a coauthor on) and another Goodman reference. Those are the ones I happen to know off hand, but I can probably get her to add more when she sees this and realized that she can have an impact. FWIW, I have paper under review that shows that the Perry & Parsonnet commentary, while it looks convincing on its face, is actually mathematically completely wrong (based on some errors in their model, as well as further Bayesian analysis of the competing claims in light of the evidence). I suspect that that level of detail and debate is beyond the preferred scope for this forum. To clarify one point: The only thing that is 100% clear on this point is that no one should be confident that there is not widespread spontaneous elimination because we simply do not have enough data about enough populations (the belief comes from case-report-type observations of lack of spontaneous elimination in adults who are being treated for clinical symptoms, but such people are quite likely different from the average case). The actual evidence goes a step further (though is not necessary to make that point): There are several studies by several resarch teams that show what looks like spontaneous elimination, particularly in children. Thus, while there is no definitive proof (as is the case with a lot of things) there is actually more evidence to support the claim that there *is* spontaneous elimination (some evidence) rather than the historical dogma (very little generalisable evidence). I can make that more clear in the article if such expositions are appropriate -- I think Dr. Goodman had some of that point in her original entry. Carlvphillips 04:31, 22 September 2006 (UTC)

• Outstanding - thanks for adding the references. And don't worry about "sounding rude"; as you noted, electronic written communication has limitations in conveying tone and intent - I took no offense. I made some small, technical changes to the formatting of your references for continuity, but otherwise they were great.

The issue of "what level is appropriate on a given topic" is a tricky one on Wikipedia - and one for which there isn't likely to be a single answer. Some of the WP style guides (Wikipedia:Guide_to_writing_better_articles#Think_of_the_reader might be a good place to start) have some generally useful ideas to keep in mind.

Again, thanks for the excellent addition; I hope you'll continue editing at WP for a long time to come. -- MarcoTolo 20:46, 22 September 2006 (UTC)

[edit] Virulence factors

This is a great article but some of the major virulence factors of H. pylori are not mentioned in this acticle, e.g. VacA and HP-NAP. Would anyone mind if I fill in the gaps? Dabalk 14:30, 23 January 2007 (UTC)Dabalk

[edit] Conversion of urea into ammonia and bicarbonate

I've went through Image:H pylori ulcer diagram en.png and the main article about urease itself. Apparently, both show that the products are ammonia and carbon dioxide, which is different from what is written here (bicarbonate?) From what I understand, bicarbonate and carbon dioxide differs much. Is there by any chance that the urease in H.pylori converts urea into different products? Nevermind, I figured that out myself. — Yurei-eggtart 07:59, 1 February 2007 (UTC)

[edit] Role of pyrogenic (inflammatory) factors in invasion

Under the heading 'Structure of the Bacterium', a previous revision stated that 'It remains unknown how this mechanism is advantageous to the bacterium'. I reviewed the reference tag, and the discussion of the published article reads:

"Epithelial cells recognize and respond to an array of bacterial products, such as LPS, peptidoglycan and flagellin. These products are highly conserved among both pathogenic and commensal microorganisms. The precise 'cues' that are used by epithelial cells to discriminate between these different classes of microorganisms have yet to be clearly elucidated. One possibility is that pathogenic bacteria, by virtue of their virulence properties, are more likely to present such products to their cognate recognition molecules in target cells. For enteric pathogens, this is most likely to occur as a consequence of epithelial cell invasion by bacteria. Indeed, invasive enteropathogens, Shigella flexneri and enteroinvasive Escherichia coli trigger proinflammatory responses in epithelial cells via signaling by the intracellular host defense molecule, Nod1 (refs. 18,31). Here we have described a previously unknown mechanism by which an essentially noninvasive pathogen, H. pylori, is able to mediate proinflammatory responses from the outside of epithelial cells."

Which seems to indicate that the inflammatory response is beneficial to invasion. (This makes sense, as inflammation is often a factor in pathogenicity.) I have left the edit open-ended, so as not to be misleading in case it is incorrect.

For your point of view, this sentence (p.1172) would be better reference.

"The fact that the cagPAI has been retained by a proportion of H. pylori strains suggests that it is likely to be of benefit to the bacterium. Thus, the induction of Nod1-dependent signaling in host cells may actually facilitate bacterial survival and replication within the host. Alternatively, it is possible that the inflammatory responses triggered by the cagPAI represent one facet of a 'double-edged sword', the other of which is to promote host colonization via a mechanism independent of Nod1 signaling."

The author actually suggests that Nod1 induction (by peptidoglycan injection) may facilitate the bacterial survival in the host (though not "invade host tissue"). However previous revision is better yet, though your revision may be also acceptable later, I think. Because first principle of cellular Nod1 induction is the host defense, as described repetitively in the paper, it is natural to consider that most part of the inflammation act as host-defense response than as bacterial benefit. The beneficial role for the bacteria of "peptidoglycan injection", not whole cagPAI, seems to be rather speculative yet. --Y tambe 03:16, 6 February 2007 (UTC)

[edit] Role in gastric cancer

According to DOI:10.1111/j.1572-0241.2006.01109.x, Helicobacter is necessary for carcinogenesis of gastric cancer & lymphoma. They suggest long-term follow up for previous H pylori carriers. JFW | T@lk 14:31, 1 April 2007 (UTC)