E. coli is in the news a lot for its role in causing “food poisoning”, which kills and sickens huge numbers of people every year. In this post I will briefly review the most comprehensive study (2008) to date on the use of a remarkable probiotic with the potential to both treat and prevent E. coli infections. If you choose to follow the link at the end of the post to read the whole study, you’ll also find links to hundreds of related studies, many of them more current.
(Some readers may wonder why I post so much on the subject of gut bacteria when this blog is nominally about the Coca plant and its medical potential. The two subjects are closely related, and although it may be years before we see open access to pure, natural Coca Leaf and its healing potential, research into the role of gut bacteria in mediating the balance between whole body health and disease is exploding. I have received strong messages of encouragement from readers of this blog to continue to point out information resources that may be relevant and helpful for those who are struggling with gut disease.)
According to the website http://www.about-ecoli.com/ : “The E. coli that are responsible for the numerous reports of contaminated foods and beverages are those that produce Shiga toxin, so called because the toxin is virtually identical to that produced by Shigella dysenteria type 1. The best-known and also most notorious E. coli bacteria that produce Shiga toxin is E. coli O157:H7. Shiga toxin–producing E. coli (STEC) cause approximately 100,000 illnesses, 3,000 hospitalizations, and 90 deaths annually in the United States. Most reported STEC infections in the United States are caused by E. coli O157:H7, with an estimated 73,000 cases occurring each year. A study published in 2005 estimated the annual cost of E. coli O157:H7 illnesses to be $405 million (in 2003 dollars), which included $370 million for premature deaths, $30 million for medical care, and $5 million for lost productivity.”
Perhaps it is needless to point this out, but this data is only on the US – the toll taken by E. coli worldwide is in the millions of people, disproportionately the very young and very old.
Because antibiotics are not effective against E. coli there is no treatment for this potentially deadly infection – doctors are limited to hydrating and nourishing the patient while their immune system attempts to overcome this tenacious invader. Meanwhile, E. coli is busy attacking the victim’s gut using multiple strategies. The bug’s primary weapon is its ability to attach itself to the lining of the gut and produce lesions. These lesions break down the tightly-bound specialized cells of the gut lining, which are designed to keep large molecular structures from passing through the gut wall, producing a condition known as “leaky gut”, which can trigger a range of dangerous immune system reactions. An E. coli infection also produces acute diarrhea, hemorrhagic colitis, and hemolytic-uremic syndrome among other potentially life-threatening outcomes.
The study that is the subject of this post, published in the journal “Infection and Immunity”, is entitled “Lactobacillus rhamnosus Strain GG Prevents Enterohemorrhagic Escherichia coli O157:H7-Induced Changes in Epithelial Barrier Function”.
While this is a lengthy and complex paper, here is how the authors “bottom line” their findings:
“Taken together, the results of this study indicate that L. rhamnosus GG has the ability to protect against E. coli O157:H7-induced damage of the epithelial monolayer barrier function by preventing changes in host cell morphology, A/E lesion formation, monolayer resistance, and macromolecular permeability. In addition, L. rhamnosus GG pretreatment prevents E. coli O157:H7-induced morphological redistribution of intercellular tight junction proteins and a decrease in the expression of ZO-1.”
“We expanded findings of previous investigators by demonstrating that L. rhamnosus GG pretreatment interrupts the infectious processes of E. coli O157:H7, without bactericidal activity. By demonstrating the mode of action of this probiotic strain in attenuating E. coli O157:H7 infection, we expanded our knowledge regarding the unique protective contributions of this specific probiotic bacterium when it is cultured with epithelial cells. It is increasingly recognized that the effects of probiotics are both species and strain specific. Accordingly, it is important to better define how individual probiotics elicit their beneficial effects as biotherapeutic agents against pathogen-induced disorders of the gastrointestinal tract”
Perhaps the most important thing to keep in mind when reviewing this research is that it was performed “in vitro” – literally in petri dishes, and not “in vivo”- in living organisms such as mice or humans. So we can’t take the findings of this research and conclude that the probiotic Lactobacillus rhamnosus Strain GG will definitely prevent E. coli infections in the human gut and/or prevent or limit damage from E. coli infections in humans once they have occurred.
However, while we can’t draw those conclusions based on this research, after reading this research carefully we can legitimately conclude that there seems to be a very high likelihood that Lactobacillus rhamnosus Strain GG will do just that.
When you follow this link you will land on the full article in the journal “Infection and Immunity”. The article is long and detailed and requires a certain amount of scientific and medical vocabulary to gain a full understanding of what the cited research does, and does not show. However, as long as you are not intimidated by technical language, if you follow the link you’ll find an even greater treasure trove of informatio on this article’s National Institutes of Health webpage.
Just to the right of the Title & Authors you’ll see a feature entitled “Similar Articles in PubMed”. As you look down the short list of articles you’ll see a link that says “See All”. If you click that link you’ll get to a page that shows you the first 20 of 198 similar articles. They are displayed 20 to a page by default, but you can change that by looking at the very top of the page and clicking the down arrow next to “20 per page”. That down arrow will then give you a drop-down menu that will let you choose to display up to 200 citations at one time. If you choose this option you will have all 198 citations on a single page, making it much easier to save the whole list for your leisurely inspection.
Here is the main article link: