Joanna wrote:So this transference would be from eating beef?
I have to agree with Sara - since meat in general, (and beef in particular), isn't classified as a high-histamine food, and since those bacteria are confined to the intestinal tract of cattle, we probably don't get any of these bacteria from eating beef, (unless we eat the contents of the rumen). Of course, the possibility of contamination is always present, since it's not uncommon for the rumen or other parts of the GI tract to be breached during the evisceration process, and the contents of the rumen to be spilled on parts of the carcass, during slaughtering, and then washed off, either with water, or a disinfectant wash. With poultry processing, for example, that's almost guaranteed to happen. With beef and pork, it's much less common.
However, noting that the bacteria are also found in horses, suggests that they may be found in other species, but apparently only in animals with significant fermentation capacity. With cattle, for example, most of the fermentation takes place in the rumen, prior to gastric digestion. By contrast, even though horses are monogastric, (humans are obviously monogastric, also), horses have extensive fermentation capacity downstream of the stomach, which allows them to digest both forages and concentrates, (grains).
Since the bacteria are found in the cecum of horses, (downstream of the small intestine, and presumably nowhere else), and in the rumen of cattle, (upstream of the stomach), that suggests that the bacteria are very adaptable, (presumably the environment in a bovine rumen would be significantly different than the environment in the equine cecum, but I don't know that for a fact), which implies that they may well have the capacity to survive in the digestive systems of other species.
OK, lets analyze the problem. The rumen in cattle normally maintains a pH in the range of 6.7 to 6.9, when hay is being utilized as feed. However, when grain is fed, the pH typically declines to as low as 5.5, (an acidic state which can result in a dangerous condition known as acidosis, if it goes too far). Normally, in a healthy rumen, lactic acid production is balanced by equal lactic acid utilization. As a result, lactic acid is typically maintained at below detectable levels, in a healthy rumen.
http://www.dfrc.ars.usda.gov/Research_S ... S96-40.pdf
http://ag.udel.edu/anfs/faculty/kung/ar ... cattle.htm
Likewise, the pH of the cecum of a horse, is typically near neutral, (7.0 is neutral), but if too much grain is fed, the pH can drop, (resulting in adverse systemic health effects, including liminitis). Since the digestive system of a horse is more similar to the human digestive system than the digestive system of a cow, lets consider equine digestive system anatomy. The article at the following link shows a sketch of the equine distestive system:
http://microbewiki.kenyon.edu/index.php/Equine_cecum
Not that the cecum is roughly 4 feet long, and is utilized as a fermentation chamber. You can read the discussion of the studies mentioned there, to see the link between the presence of gram positive, lactic acid producing bacteria in the cecum and downstream GI tract, and the appearance of potentially serious systemic symptoms in horses, (including laminitis). Apparently, research is ongoing, to determine whether probiotics may be effectively used to prevent laminitis in horses. Remember, laminitis is the condition involving inflammation of the laminae within the hoof, which has been connected with A. histaminiformans, an intestinal bacteria that is known to decarboxylate histidine, and produce histamine.
http://www.reeis.usda.gov/web/crisproje ... 16798.html
OK, looking at all this, what can we infer from it? Well, obviously, the fermentation of forage is fine, (in digestive systems specifically designed to handle it), but the fermentation of grains often leads to serious problems, even in digestive systems that are much more adaptable to alternate forms of feedstock than the human digestive system. Also, remember that the human digestive system is not designed to handle any significant amount of fermentation - anything more than minor levels of fermentation in the human digestive system leads to gas, bloating, cramps, D, etc. If cattle and horses can't handle large amounts of grain without risking serious adverse consequences, why should we expect to handle grain, with our inferior digestive system?
Since the issue that apparently leads to acidosis, (and the subsequent adverse systemic effects), is the presence of gram positive bacteria with a propensity for producing lactic acid, it would appear that probiotics might be beneficial for combating this imbalance. However, note that the Allisonella histaminiformans strain is gram negative, (even though they seem to be most closely related to certain gram positive bacterial strains, (Dialister pneumonsintes, Megasphaera elsdenii and Selenomonas ruminantium). That doesn't mean that any given probiotic that might be helpful for combating a lactic acid imbalance wouldn't also be effective at limiting A. histaminiformans populations, but it might open the door for the possibility that other strains, (or even a unique probiotic strain), might be needed.
Also, note that the researchers involved with the project linked to above, apparently aren't even aware of the A. histaminiformans connection with laminitis - they are only seeking a way to control lactic acid imbalance. It will be interesting to see whether they are successful in discovering any beneficial probiotics, since they don't even have the problem defined properly, (the first rule in solving a scientific problem is to properly describe the problem.) Of course, they may still be successful, by accident.
Anyway, IMO, the common link here is fermentation. A. histaminiformans only exists, (normally), in cattle and horses, in digestive system zones where fermentation is the primary mechanism of digestion. Human digestive systems are very poorly adapted for fermentation processes, and IMO, if we allow them to take place, we open the door to the possibility of encouraging undesirable bacterial populations, (such as A. histaminiformans, or some mutated relative of them). Eliminating grains from the diet greatly reduces that risk, IMO.
Love,
Tex
Visit the Microscopic Colitis Foundation Website
I'm glad you noticed it because I'm so used to being told, "it's because you're getting older", I didn't thick twice about it.
