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Discussion Starter · #1 ·
I am posting this here since it is off topic for the other thread . It is about methanogenic and sulfate reducing bacteria Title: Interrelations between populations of methanogenic archaea and sulfate-reducing bacteria in the human colon. Author: Pochart P , Doré J , Lémann F , Goderel I , Rambaud JC Source FEMS Microbiol Lett, 77(1-3): 225-8 1992 Abstract: In humans, CH4 is produced in the colon by methanogenic archaea and is detected in breath samples from approximately 50% of healthy adults, identified as CH4-excretors. Methanogenesis and sulfate reduction have been described as two mutually exclusive processes, potentially regulated by sulfate availability. To determine whether microbial population balances reflected these apparently co-regulated activities, we compared sulfate-reducing bacteria, methanogenic archaea, sulfate and sulfide concentrations in faeces of 10 CH4-excretors (CH4+) and 9 non-CH4-excretors (CH4-). The mean +/- SE of the logarithm of methanogenic archaea per gram wet weight were 9.0 +/- 0.2 and 4.0 +/- 0.7 for CH4+ and CH4-, respectively (P < 0.001). Sulfate-reducing bacterial counts were 6.5 +/- 0.1 and 7.3 +/- 0.2, respectively (P < 0.001). Fecal sulfate and sulfide concentrations did not differ between groups. These results suggest that a competitive interrelation between methanogenic archaea and sulfate-reducing bacteria occurs in the human colon. However, it does not lead to a complete exclusion of the two populations The paper seems to differentiate between the process and the population. It seems to say the populations are not mutually exclusiveAnd am repeating a question from the last thread bcos maybe you missed it - Do you know the names of malodorous gases made by non sulfate reducing bacteria?
 

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I tend to think you may have a few lurkers hanging out of one species or the other just waiting for an opportunity to turn the balance over so one type doesn't kill off the other type completely, but the dominant species supresses the other.And lots of bacteria can hang out in a dormant state for long periods of time waiting for the right moment.Don't know of malodorous gasses produced by non-sulphide reducing bacteria but odors can come from foods like onions and garlic or be the breakdown products of fatty acids which may be volitile enough to exist as a gas.Altering diet can significantly alter the odor of pig poop, so I expect the same could be for humans as well.Chlorophyll tablets can reduce odors in some people.K.------------------I have no financial, academic, or any other stake in any commercial product mentioned by me.My story and what worked for me in greatly easing my IBS: http://www.ibsgroup.org/ubb/Forum17/HTML/000015.html
 

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Discussion Starter · #3 ·
I too tend to think that those vile sulfate-reducing bacteria are always lurking around. I'll try to see what kind of a role diet plays but I do love onions. And thanks, chlorophyll indeed helps.
 

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You might try lowering the percentage of proteins in the diet as amino acids are one of the sources of sulfur in the diet and most of us get more protein than we really need.K.------------------I have no financial, academic, or any other stake in any commercial product mentioned by me.My story and what worked for me in greatly easing my IBS: http://www.ibsgroup.org/ubb/Forum17/HTML/000015.html
 

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Discussion Starter · #5 ·
Malodor is not really a problem for me anymore since gas is no longer a problem. I am curious about the science of it, though. It's great having access to people with scientific knowledge like you and flux. So much better than encyclopedias! By the way , thanks for telling me about infotrieve.com, I am like a kid in a candy store with itOn another note-for gas I have to eliminate fructose (i.e veggies and fruits and wheat) and anyway carbohydrates tend to be bad for gas and now if I eliminate protein for malodor , what am I going to eat!!! You see the G people have it the worst.
 

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That can be a problem... and often times mucking with one part of the diet mucks up other things so it's a balancing act.Chicken was in one list of potential bad odors.... not sure why that in particular. It can be something to play with, trying different protein sources see if one is better than another.Some people find odor the biggest problem not volume. But if you have odor and volume (or farts/day) reducing the volume can help alot as small amounts of smell are better than large amounts of smell and a couple of smelly farts a day may be better tolerated than farting often.One other factors is to increase your absorbance of gas from the GI tract into the bloodstream and exercise is the way to do that. If you can tolerate exercise. Aerobic things like walking/running or exercises like Taijiquan (T'ai Chi) or yoga that twist the waist may be helpful for that.K.------------------I have no financial, academic, or any other stake in any commercial product mentioned by me.My story and what worked for me in greatly easing my IBS: http://www.ibsgroup.org/ubb/Forum17/HTML/000015.html
 

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Discussion Starter · #7 ·
That is such a novel concept to me- gases being absorbed by the body. Heard it first here on this BB recently. I always thought if gas was produced it had to find its way out. Anyway thanks for all the suggestions. I think we should compile a gas thread with excessive gas list of Ugh's, Participate-foods that cause gas- and all the info about malodor. BTW the list where you read that chicken causes malodor is not available on the internet, is it? If it is, could you give me the URL for it please?
 

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It was from the Participate newsletter article I posted awhile ago Here is the odor list from thatOdorAlcohol, asparagus, beans, cabbage, chicken, coffee, cucumbers, dairy, eggs, fish, garlic, nuts, onions, prunes, radishes, highly seasoned food)I believe the article can be ordered from www.iffgd.org, but it isn't posted there.K.------------------I have no financial, academic, or any other stake in any commercial product mentioned by me.My story and what worked for me in greatly easing my IBS: http://www.ibsgroup.org/ubb/Forum17/HTML/000015.html
 

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Discussion Starter · #10 ·
quote:One other factors is to increase your absorbance of gas from the GI tract into the bloodstream
Exercise increase the absorbance.K. , Can you please tell me why? The pressure of the gases in the blood and the gut cavity dictate whether they are absorbed or not, right? So how does exercise change the pressure of gases assuming there is a simple explanation. Please excuse my ignorance of biology. Can some organic problem or some thing other than exercise affect absorbance? Thanks in advance. I tried to do a search on infotrieve but I guess I wasn'tusing the right phrase or something- the results were too unwieldy to be of any use
 

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Trying to remember where I was reading about it... what I think (my supposition could be wrong) is that it is normal for the gasses to be absorbed into the blood stream and exhaled. This is why the hydrogen and methane breath tests work. The gas leaves the intestines goes into the blood stream and it is filtered out into the exhaled air. And everyone probably has a different efficiency of doing this which is why some people tend to be gassier than others even when you look at normal people. I think what may be working with the exercise is a couple of things. When you move more blood around and breath harder you could simply be upping the transport because more blood is flowing past the intestines and the lungs (heart rate and breathing rates are up). The other thing that could be going on is that the stuff inside the intestines is getting sloshed or moved around by the bodies movement and that gets more gas in the right position to be absorbed. (has to be by the cell membranes--stuff in the middle of the intestine is out of reach).That's what makes sense to me. I'll see if I can find anything else.K.------------------I have no financial, academic, or any other stake in any commercial product mentioned by me.My story and what worked for me in greatly easing my IBS: http://www.ibsgroup.org/ubb/Forum17/HTML/000015.html
 

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This is from www.merck.com seaching for flatulence. Doesn't explain why exercise may help (but lots of sites mention exercise as helping and one article on medline mentioned that in triathletes farting and bloating were more bothersome at rest then while exercising)
quote:Gas diffuses between the lumen and the blood in a direction dependent on the difference in partial pressure. The production of H2, CO2, and CH4 may reduce the partial pressure of N in the lumen to far below that in the blood, which may account for much of the N in the lumen.Gas is eliminated by belching, diffusion from the lumen into the blood with ultimate excretion by the lungs, bacterial catabolism, and passage through the anus (flatus, farting).
K.------------------I have no financial, academic, or any other stake in any commercial product mentioned by me.My story and what worked for me in greatly easing my IBS: http://www.ibsgroup.org/ubb/Forum17/HTML/000015.html
 

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Discussion Starter · #13 ·
I see. So the absorbance just has to do with the amount of blood presenting itself to the gases rather than pressure of gases changing between the blood and gut cavity. Thanks.
 

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It seems like the partial pressures (how much is in the blood and how much is in the gut) plays a role, but the faster your blood is moving I would think you may be clearing it out faster. There is a two part equation. How much gas goes from the gut into the blood and how much gas goes from the blood into the air. So how much is more blood is going past the gut, and how much is blood going through the lungs and "outgassing" I'm not sure. Usually when you exercise you breath more often and more deeply (more air in lungs/breath) and your blood flows more, and I dunno if you could pull the two apart experimentally or not.K.------------------I have no financial, academic, or any other stake in any commercial product mentioned by me.My story and what worked for me in greatly easing my IBS: http://www.ibsgroup.org/ubb/Forum17/HTML/000015.html
 

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Discussion Starter · #15 ·
I missed the article you posted from merck bcos you and I posted around the same time. It doesn't mention oxygen(O2). Seems if O2 is used up during exercise it would create a vacuum in the blood for O2 to be sucked out of the lumen into the blood. I would prefer H2S or methanethiol to be absorbed though. But I suppose that lesser the volume of any kind of gas in the lumen the better. [This message has been edited by bonniei (edited 06-05-2001).]
 

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quote:eek: the absorbance just has to do with the amount of blood presenting itself to the gases rather than pressure of gases changing between the blood and gut cavity.
I know you love math bonniei so, the rate of absorption is governed by Fick's law of diffusion which saysJ = DA * deltaC / delta x.This says that diffusion rate J is proportional to the diffusion coefficient of the gas (D) tmes the area of the gut membrane (A) times the difference in gas partial pressure (deltaC) divided by the thickness of the membrane (delta x).I don't think blood flow makes that much difference for say hydrogen in the sense that it is always going to be fast enough that that pressure gradient is always maintained: hydrogen concentration in the blood never changes significantly enough to slow down the rate of diffusion. However, carbon dioxide because it is a neuromodulator, it can cause vasodilation resulting in increased blood flow. On top of that, CO2 is converted to carbonic acid, lowering CO2 partial pressure.The partial pressure difference is largely governed by the pressure in the blood, arterial having similar pressures to the air and venous having much less O2 and more CO2. Nitrogen is essentially the same throughout the whole body and thus there is probably no movement of nitrogen in any direction, so swallowed air goes out the way it came in, except for oxygen which is consumed by bacteria.------------------I am not a doctor, nor do I work for profit in the medical/pharmacological field, but I have read scientific and medical texts, and have access to numerous sources of medical information that are not readily available to others. One should always consult a medical professional regarding advice received.[This message has been edited by flux (edited 06-06-2001).]
 

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Discussion Starter · #17 ·
quote:I know you love math bonniei so
. And now you know Math and physics too? Anything you don't know flux?
Thanks for the formula.That helped a lot. I wish I knew more physics though .Intuitively,it would seem like the diffusion rate would need to have a factor like the rate of blood flow to the surface of the diffusion(more fresh blood -less saturated it is with some of those terrible non fresh gases -more the diffusion) but if I am to understand you correctly the difference in partial pressure and the diffusion coefficient (probably a constant containing the unit of time) factors that inAnd sounds like you are saying gases are absorbed by both the arteries and veins depending on delta C. So I guess since exercise changes the amount of O2 and CO2 and other gases in both the arteries and the veins, delta C would change and there'd some exchange of gases. One would think since there is never any H2S in the arteries( as it isn't there in the atmosphere), it would be absorbed rapidly and out of the gut. This is probably true of veins too.But probably the absorption is just not fast enough. Then there is this fact about H2S that I've read -that the absorption depends on where the H2S is formed, the distal part of the colon or the proximal part. Don't see why that should make a difference unless deltax is different in different parts of the colon. Well i am kind of just thinking out loud. Anyway, thanks as usual flux and k for helping me understand biological processes better and your input is always appreciated
[This message has been edited by bonniei (edited 06-06-2001).][This message has been edited by bonniei (edited 06-06-2001).]
 

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quote:would need to have a factor like the rate of blood flow to the surface of the diffusion
Yes, that would be the mucosal blood flow. The surface area is the surface area of the gut mucosa.
quote: saying gases are absorbed by both the arteries and veins depending on delta C.
I'd say it's a capillary bed where the blood is in between arterial and venous pressures. I think blood flow is probably normally sufficient that it can maintain a relatively constant partial pressure gradient for gases that are not in the blood such as H2S.That may not apply to CO2 because CO2 can increase blood flow and CO2 can also be converted to carbonic acid and CO2 is transported via hemoglobin so CO2 transport is complex.
quote:absorbed rapidly
If the blood is pulling out H2S faster than H2S diffusion, the rate should strictly be a function of Fick's law. We have to know the diffusion coefficient (and the solubility) of H2S in the blood to know how fast the blood can remove it and of course the rate of blood flow.------------------I am not a doctor, nor do I work for profit in the medical/pharmacological field, but I have read scientific and medical texts, and have access to numerous sources of medical information that are not readily available to others. One should always consult a medical professional regarding advice received.
 

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Discussion Starter · #19 ·
I'd say gut mucosal surface area is not sufficient to capture the entire dimension of rate. There should be a time element. That's why I thought maybe the diffusion coefficient captures the time element. Are the units of the diffusion coefficient somethin/sec?
 

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Discussion Starter · #20 ·
Actually I have thought more about it and it seems that if the rate of blood flow is increased to the gut, it probably affects the pressure gradient. The increased blood flow keeps the pressure difference high enough to bring about a higher diffusion rate than if the flow was not increased. Sorry if I am going around in circles but it is difficult to grasp that the units of presssure difference don't include time and yet it is dependent on the blood flow rate which has to do with time. Is there a formula connecting pressure difference to blood flow rate? This is getting to be a physics education for me. I won't ask any more questions on this thread.
 
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