IBS as an autoimmune condition: CDT-B & molecular mimicryVinculin bacterial toxin CDT-B SIBO post infectious IBS Dr Pimentel molecular mimicry gut pathogens autoimmune disease gram negative bacteria
Posted 07 March 2015 - 07:50 PM
I recently posted in the DIET section about the link between starch, molecular mimicry and gut pathogens. Basically a particular pathogen called Klebsiella feeds on non-fibre dietary starch. The bacteria makes a carbohydrate degrading enzyme called HLA-B27 that mimics proteins in our body. In an autoimmune disease called Ankylosing Spondylitis the immune system recognises the Klebsiella as a foreign invader but HLA-B27 also mimics the body's collagen protein, which the immune system also attacks, causing arthritis.
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Posted 09 March 2015 - 09:43 PM
I have wondered about the post-infectious possibility. I do remember having two instances of illness with diarrhea at ages 11 and 12. Prior to that I don't remember ever having diarrhea. Growing up, my mother, siblings and I would get sick once every fall with a bug where we would throw up for about 24 hours, but we didn't get diarrhea. I have read that having only vomiting from a bug is much less likely to lead to post-infectious IBS which makes sense. If you get diarrhea then the effect of the bug obviously has an effect on a larger portion of the gastrointestinal system.
And it was around that same time that I began having constipation problems- age 11-12. My older sister said that she had had the same problem at that age so we just assumed it had to do with going through puberty and it would go away. Of course it never did- it just changed through the decades.
Will be interested to hear if the blood test for the vinculin antibodies becomes available. Awhile back I heard it might even be available this year. Though I doubt if it would be widely available for quite some time as there still don't seem to be many gastroenterologists who even want to talk about SIBO, which we have known about for several years now. We'd likely have to be willing to travel to Los Angeles where Dr Pimentel works to get it. Although Dr Siebecker does offer phone and Skype appointments and can order tests through the mail if there were a lab to send it to for evaluation. She just can't write any prescriptions without seeing a patient in person. But she often has non-prescription alternative ideas to try as well.
This is from a couple of years ago, but gives a brief view into the anti-vinculin antibody research by Dr Pimentel.
Posted 10 March 2015 - 03:19 PM
Thanks so much Airplane. I'll copy & paste the info from that link you sent me down the bottom for those who haven't read it.
Have you seen this?
(the following is quoted from this website)
Future Directions for Possible Cure
FDA approval of Rifaximin • Remove the antibody to vinculin from the blood • Immunize against ever developing IBS • Turn on vinculin – New drug development • Stop methane production • Measure Hydrogen Sulfide • A new blood test for IBS
Why hasn't he suggested dietary change? Does he leave that side of things to Dr Allison Siebecker? So people just continue with their bad diets and the Rifaximin makes IBS go away? I've seen in other studies of his where he claims a high success rate with Rifaximin but most posts I've read say the IBS/SIBO returns after a few weeks. It was interesting that they don't view it as molecular mimicry or they're not sure about this. It makes it sound as though the bacteria is deliberating targeting vinculin(?). It sounds like the pathogens are doing this to protect themselves. Very interesting anyway. Please update if you find out any more news about this.
(the following text is quoted from this link)
"Irritable bowel syndrome has been a diagnosis of exclusion, where we first have to rule out all sorts of other diseases and then apply the Rome criteria. But those criteria aren't specific, and in one study we found that only 67% of IBS patients met those criteria," he said.
There has not been a valid biomarker of the disorder, so most patients undergo extensive and expensive testing.
To address this diagnostic gap, he and his colleagues have been exploring the pathophysiology of IBS, and have found that in many cases, the condition arises after an episode of gastroenteritis, with bacterial overgrowth in the small intestine resulting from neuromuscular damage.
Animal models showed that a specific toxin produced by gastroenteritis-causing bacteria such as Campylobacter jejuni known as cytolethal distending toxin B (CdtB) can precipitate IBS.
So Pimentel's group developed an antibody to the CdtB toxin and applied it to full thickness biopsies of rat intestine, and found that the antibody bound strongly to all the neuromuscular elements, but in both exposed and control animals.
"So the antibodies to CdtB were reacting to something that was part of the host, not to the presence of the toxin," he explained.
Then, through a series of experiments, they considered if this was molecular mimicry, but eventually with immunoprecipitation testing determined that the antibody was targeting the human protein vinculin, which is important for nerve cell migration.
They also considered the possibility that exposure to the toxin led to the development of antibodies that could react to CdtB epitopes, and whether through homology perhaps one epitope produced an autoantibody to the protein.
"Our hypothesis was that in humans, some people never had gastroenteritis, never developed antibodies to CdtB or vinculin, and never developed IBS. Or they did have gastroenteritis, produced the antibodies, and then developed IBS," he said.
Posted 10 March 2015 - 08:18 PM
Dr Pimentel said that it was his career goal to have IBS viewed as a disease rather than the syndrome like it has been for the past 20 or more years, like supposedly being caused by lifestyle choices. Which makes sense- as we have discussed here, why can some people eat a food with little or no problems, while some of us suffer big-time from the same food. And why didn't these foods bother us before we got the so-called IBS? Yes, there can be things like heredity (like Asians reacting worse than others to dairy because it hasn't been part of their culture so they lack the digestive enzymes for it) but that would be one of the exceptions, I would think.
When you mentioned the part where it sounds like maybe pathogens are protecting themselves, it reminded me of the biofilm train of thought. I have never heard of Dr Pimentel mentioning biofilms, but so far that is the only idea I have heard that might explain antibiotic-resistance, and why some people initially do great with Rifaximin or other antibiotics, but if the SIBO returns and they try it again, it may not work again. And this can happen with other health issues as well. Had I known more about antibiotic-resistance- and the possible negative effects on my microbiome- sooner, I never would have taken repeated courses of Tetracycline for acne in my early 20s which never helped the acne for long anyway. Every time I finished taking the Tetracycline, the acne came back worse. I finally got on Accutane which is what I wanted in the first place but the Dr was stubborn about giving it to me because it was controversial due to possibly causing birth defects if used during pregnancy. I told him that wouldn't be an issue for me but he still refused. Many in the medical field are now recommending the development of newer, 'Narrow Spectrum' antibiotics that only target what needs to be treated, and to stop using the current wide-spectrum ones so much. But that still doesn't sound like it would be the total answer either. Seems like the more we learn about bacteria, the more we are realizing just how strong and intelligent they can be when their survival is threatened.
Dr Pimentel did give dietary guidelines in his book. It isn't as strict as most of the other diets. I remember he said absolutely no artificial sweeteners, no dairy or high-residue foods. Mostly to eat foods that are easy to digest and are absorbed higher up in the GI tract. He said that sugar was bacteria's favorite food so we should limit that. I don't think that things like FODmaps were being talked about at the time. When I tried the low-carb diet a couple of years ago, I had read William Davis's book 'Wheat Belly'. I still have the book-maybe I should read it again. It is difficult though. I gave up eating meat and poultry in my teens and have no desire to eat them. I do eat seafood but it can be difficult because you hear so much about antibiotic-laden, sometimes mislabeled contaminated fish raised in filthy conditions, besides the mercury. It is easier to figure out what NOT to eat than it is figuring out what TO eat!
Posted 11 March 2015 - 07:39 AM
Dr Pimentel’s diet is the exact opposite of what I've been doing the last week - and my diet has been working very well (when I don’t overdo the nuts). Everyone with IBS tells doctors that fibre causes worse symptoms and I used to say this too. I guess after a while the doctors believe it and tell IBS sufferers to go easy on the fibre and that a low residue diet is best but this is where it gets tricky.
Posted 11 March 2015 - 10:05 PM
When I get a chance I will have to read the entire interview with Dr Siebecker in the link you gave as I see it mentions resistant starch. I agree that Dr Pimentel probably isn't as knowledgeable about diet as Dr Siebecker. I am familiar with low-carb but am not quite sure how that differs from low or resistant starch. I do try to eat only whole foods and avoid packaged convenience, 'just add water' junk. I do have a piece of gluten-free toast with almond butter and a small serving of organic, gluten-free granola in the morning with one cup of black tea. Dr Davis doesn't approve of most gluten-free products because they contain a lot of junk ingredients so I pretty much only have the one piece of toast a day.If I had the time (and a bigger kitchen which is shared by others) I would try making my own bread with nut flour as he suggests. One thing I disagree with is that he thinks Xylitol is a safe sugar substitute- which I heard Norm Robillard does too. I think Stevia leaf is the only safe alternative sweetener, and even then there are only a few brands that don't have added ingredients or alcohols.
Using lettuce for a bread substitute is a good idea. There is a gourmet submarine sandwich shop that offers that. I also sometimes just put what I normally would have had as a sandwich in a salad- tuna, olives, tomato, etc. I am reading your diet diary and hope you continue to have good results. I imagine it is a bit of a balancing act. The meat could be constipating, but the fat and some of the vegetables should help. I hear about a lot of people consuming coconut oil lately. I did buy a jar of it awhile back but wasn't sure what to do with it so ended up throwing it away. But I see it more and more in the grocery stores lately so it must be popular. Also it seems like juicing is pretty popular but not sure if it would make some of the vegetables-like kale- more tolerable. I do think I react badly to high-sulfur foods- both vegetable ones and eggs. The gas they give me is very crampy, hot and foul so must avoid. Eggs are OK as an ingredient but I can't eat them whole which is too bad. I loved them as a child, plus they are a good source of nutrients for a healthy head of hair.
Posted 12 March 2015 - 05:10 AM
Posted 12 March 2015 - 06:49 AM
I can't find my copy of Dr Pimentel's book, but from what I remember, I think he would agree that resistant starch (what I call high-fiber or high-residue foods like whole grains) is not good for SIBO because while we don't digest them, the bacteria will. While that is supposedly good for the health of the large intestine (I would assume that is if you don't have dysbiosis there in which case they could cause a flare-up) it is not good for the small intestine if SIBO is present. I do remember that he said if you did eat bread, then white bread was preferable to whole grain because it didn't have so much residue to feed the bacterial overgrowth.
Like you, I try to do whatever it takes to avoid having symptoms in public. And that can mean doing things that some experts would strongly disagree with. When I start having cramps and gas in public, I do take a pain med called Tramadol which seems to calm things down. I know that Dr Siebecker does not like pain meds because they interfere with the MMC and even blames them for the development of SIBO in some people. But when you have to go to a job or somewhere else, you just have to do what is necessary for the short-term while continuing to try other things to prevent symptoms in the first place. That is why, even if I could find a good alternative practitioner to help me figure this out, many of them don't get it that we may have to do things they don't approve of just to function. But that shouldn't mean that we still can't continue working on improving our condition.
Good luck with the stool test. If I wanted one done I would have to do it though the mail since gastroenterologists in my area don't offer them except for checking for blood. I have read of one called the Comprehensive Digestive Stool Analysis being a good one. However, even then I think you can only find out so much. I remember reading of another patient who was seeing an alternative practitioner and had a stool test done. The test results showed a lack of some good bacteria and the practitioner recommended a specific brand of probiotics. The patient said that they were already taking that probiotic. Which makes you wonder just how effective they are, as we discussed previously.
Posted 13 March 2015 - 02:59 AM
Posted 13 March 2015 - 09:34 PM
What I'm not sure about regarding the new pill cam is whether it will help diagnose gas in the entire digestive system or only the large intestine. Would hope it would also include the small intestine but it is hard to tell. There are several news articles about it, including in the IBS News Reporter Section where I think there are 12 or more write-ups on it. Since the current SIBO tests don't seem too reliable it would be nice to have an alternative. Sounds like there will be clinical trials for it. If they had one near me I would sign up assuming I met the criteria.
I haven't found my copy of Dr Pimentel's book to look at the sample diet he gave. Have you read his book? It likely is a bit outdated by now. I do think that most Drs aren't big on investigating diets- most of them want you to go to a dietitian if they think you need help with that. Or yes, they give you really bad dietary advice. I had thought that Dr Siebecker's book would be out by now but maybe it got delayed due to how fast information comes out or changes, so then no book about SIBO would be current for very long.
Posted 14 March 2015 - 02:35 AM
I think really it all comes down to just experimenting with diet until you find something that gives you the least symptoms. No-one really can ever give you dietary advice for you. You have to figure this out yourself. One person here might have a problem with starches but they’re OK with fibre. Others might be the opposite. A healing diet for IBS-C or Leaky Gas might be totally different to one for IBS-D. Most of us don’t even know what’s wrong with us. That’s why all these diets are doomed to failure because it’s such a personal thing and we’re all still trying to figure things out. I do believe though that certain foods are naturally toxic for everyone with IBS - refined starch and sugar for example, and I wouldn’t support any doctor with my cash if they were pushing foods like this, which is why I didn’t buy the low FODMAP cookbook. I’m pretty sure grain starches are toxic for everyone with IBS but it’s so hard to prove and nothing’s conclusive with testing. I don’t think fibre is naturally toxic, but it can be inflammatory for an already inflamed colon simply because the natural drive of fibre is to push through. If you’ve got stodgy stuff in there that’s sure to create a lot of gas. In my case, I know what I have to do but this involves a certain level of hunger and I really have to force myself not to overeat because for me this is the biggest trigger.
Posted 14 March 2015 - 11:15 AM
I think it does come down to finding out what causes the least symptoms. As long as we have to eat I think that most of us will always have symptoms. I haven't tried a fast so for all I know I might still have a lot of symptoms even then. I have looked at the proposed pre-digested supplements for fasting, like Vivonex, but they are expensive and contain questionable ingredients. I think Dr Siebecker has a recipe for making your own but don't remember what is in it- I do not consume anything to do with meat or poultry as a personal preference, not for IBS reasons. But even then, that can mess with your metabolism, especially if you gain weight easily, and I imagine that it would be tricky when you started eating again. I remember that in the 1970's there was a fad of using only liquid protein for weight loss but it obviously was short-lived.
Posted 14 March 2015 - 03:43 PM
Posted 15 March 2015 - 02:12 PM
This article also mentions a third gas, hydrogen sulfide in addition to the hydrogen and methane. I have heard about this third type of gas before but not read much information on it. It says that it should be treated the same as methane.
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Posted 15 March 2015 - 04:32 PM
thanks, Airplane, for that link.
that's the diet i've been following for quite a while.i found it on another website..i don't eat pasta, rice or bread though. like it says, you need to experiment to find what works for you..
these are just my own thoughts. for expert medical advice please contact a health care professional.
Posted 15 March 2015 - 08:54 PM
One thing that I noticed in the Dr Siebecker link was the mention of a probiotic that provided symptom improvement in 82% of the patients that took it. It looks like it was called Bioflora. I tried searching for it. There was one on Amazon with that name but it wasn't the same one- totally different ingredients. What I gathered about probiotics is that you definitely don't want one with prebiotics, and also no Lactobacillus Acidophilus which apparently is found in high amounts in SIBO patients, but I notice that it is a common ingredient in many brands. I looked up one of the strains in the probiotic she mentioned, streptococcus faecalis which I don't think I have seen in any brands, and it sounded like a questionable strain. Still, 82% sounds promising, even though the trial didn't have that many participants. If I could find it I would give it a try.
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Posted 16 March 2015 - 04:35 AM
Posted 16 March 2015 - 04:58 AM
Airplane--thanks for the pub med link and the information on bioflora. yes, if i could find it, i'd give it a try, too.
i'm scheduled for the HBT on friday IF i get insurance approval in time which is a big "if" because the hospital always drags it's feet in starting the insurance approval process. i've had tests there fall through in the past because of this problem. no insurance approval = no test.
i just wish my gastro would let me try antibiotic treatment without the test like i've read some gastros do since the test is so inaccurate. i think there's a very good chance i have SIBO because i had open abdominal surgery in 2013 -a right hemicolectomy--during which about 4 inches of distal ileum was also removed. ever since then, my gas and bloating have been so much worse.
these are just my own thoughts. for expert medical advice please contact a health care professional.