I was unsure what to do with the figure "60% of the dry weight", because I didn't readily know how much the dry weight is (turns out about 30% of a healthy persons average 4oz moist stool - much less % for those of with high moisture content from blood, mucous, water). But more important, I don't know how to assign any signifigance to "60%" - other than to underscore that we all have lots of gut flora. Since the dry mass is only the nutrients we could not absorb (e.g., insoluble fiber), and those minerals we constantly excrete (e.g., chrominum, nitrogen), it is good that most of our food is absorbed. So, it is not surprising that about half of the dry mass comes from the many many bacteria floating in the luminal (i.e., cavity) gut. After all, they are just floating and don't swim upstream or anything. I think we need to be careful about letting the odd or suprising sounding statistic lead our attention, and instead keep the focus on what/how/when probiotics are theraputic. I was glad the OP stressed selecting strains that had evidence to recommend their use.
Overall, I am in general agreement with the OP. I just want to caution against premature or excessive zeal.
From postings here and medical literature I have been reading, I am convinced that some probiotics have a role to play in managing UC. Possibly a role in the etiology of UC. I do note that they may play different roles (or not have a role) in the cause, treatment, and management of remission - each phase of UC may be different, and there is just not enough research yet. I am in the process of increasing the role of probiotics in my daily medications. But, I do want to raise a few cautions and clarify a few points, since this discussion has been pitched by the OP as scientific in nature.
My GI will readily recommend Align brand OTC probiotics to UC and other GI patients, and is wiling to write me a prescription for VSL#3 (I need to compare prices for OTC VSL#3 and prescription VSL#3 DS and get back to him.) I think that when docs are more ambivalent about probiotics it may be for several logical reasons: 1) some positive research is very recent, 2) there are conflicting research reports, 3) exactly how they work is still largely unknown, 4) the benefit seems to depend on which particular (out of hundreds) of strains is used, 5) probiotics are IMPLICATED, but are certainly not the ONLY important factor. 6) without more clinical evidence, GIs who advocate anything other than FDA approved drugs, are at risk of being sued in our litigious society by any patient that does not have a good outcome.
As for "profit motive" discussions, while there is no big profit motive for pharmaceutical companies to research and develop the types of probiotics that would not qualify for patent protection, there is plenty of profit for the supplement industry to do this research, as well as potential genetically modified strains of probiotics that would merit patent protection.
I say this because I largely reject assertions that doctors and pharmaceutical companies have a conspiracy to keep us sick. That kind of talk is silly in my opinion, although I agree that for-profit medicine does create certain conditions (without needing a conspiracy) that might be less than ideal. The review articles below (which in turn reference numerous individual studies) attest to the active research in this area. The problem is just a lot more complicated and the process is just a lot more slow and ponderous than most laypersons realize.
I am easily overwhelmed by the complexity of leading edge medical research reports. The immune system is so complex and the language is so difficult. But I can manage to get a bit more out of review articles, or at least the abstracts of review articles. I am listing 6 encouraging reviews below, but I am not saying everyone has to go and read them unless you want to. They generally relate 4 basic points:
- beneficial gut flora do seem to play a role in immunological response of the mucosal lining
- the exact mechanism is largely unknown, but seems to include regulation of Treg as well as Th17 elements of the immune system
- molecules on the surface of certain probiotics seem to be at the root of this regulation process
- other benefits more specific to helping the mucosal lining keep toxins out of the body (as opposed to inflammation response benefits) seem related to some probiotics adhering to the mucosal lining and preventing undesirable bacteria from adhering, and may also more generally displace (e.g.,"starve out") some of the bad biotics.
Even while probiotics gets more necessary research, it does make sense for those of us searching for better management of UC, to try things like probiotics. There does seem to be some benefit from some probiotics for some patients. Also, there does not seem to be much downside or toxic side effects. But we should also keep an ear out for the newest research, and not be crazy as to broadly endorse any and all kinds of probiotics at any dosage administered from either end - and especially not to promote probiotics to the exclusion of other therapies. I was very glad the OP stressed also taking the medications.
Being implicated as having "a role" does not mean other factors may not have an even greater role. Also, until more is known about how they work, it is not gauranteed that the way they atually work might not undermine the way some other treatment works. It would sure suck if it turned out that the exact way probiotics worked greaty undercut the effectivness of 5-asa drugs. Also, there is almost no research on potential harm from overdosing on probiotics, or even what would constitute an overdose. Rectal administration of probiotics has hardly had any study.
I think it is also wise to stick with name brands (or trusted companies) that have been used in actual medical trials. Remember that the supplement industry is not well regulated and they can change formulas, or manafacture methods, and/or make claims that are not evaluated by the FDA. The consistientcy and potency and shelf-life of supplements is generaly not well studied. Generic versions of supplements often vary greatly in propotion of active ingredients form pill to pill and bottle to bottle. It is just not regulated. This may be the best reason for selecting VSL#3, because the DS prescription version is at least regulated by the FDA.
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1. Ann Ital Chir. 2011 Sep-Oct;82(5):361-8.
From gut microflora imbalance to mycobacteria infection: is there a relationship with chronic intestinal inflammatory diseases?
Tomasello G, Bellavia M, Palumbo VD, Gioviale MC, Damiani P, Lo Monte AI.
Facoltà di Medicina e Chirurgia, Università degli Studi di Palermo, Palermo, Italy.
The gut of a healthy adult harbours a myriad of different microbial species. It is estimated that approximately 10 14 are present in total bacterial colony forming units (CFU). Each colony colonizes a specific intestinal tract. In healthy adult, the main control of intestinal bacterial colonization occurs through gastric acidity but also other factors can influence the intestinal microenvironment such as pH, temperature, competition among different bacterial strains, peristalsis, drugs, radiotherapy and much more. Impaired microbial homeostasis leads to an alteration of the permeability of tissue, together with the activation of the intestinal immune system MALT (mucosal associated lymphoid tissue). In this regard we discuss the increasing experimental evidences of the role of commensal microbiota in the activation of specific intestinal immunocompetent cells. The aforementioned micro-environmental changes provide the substrate for the etiopathogenetic outbreak of numerous pathologies of gastro-intestinal tract, such as intestinal chronic inflammation (Crohn's disease and Ulcerative Colitis), together with a miscellany of extra intestinal disorders. This article is an overview of the latest scientific findings about the close causal relationship between intestinal microbial flora and inflammatory bowel diseases or other extra-intestinal diseases; it is also mentioned the possible relationship between mycobacteria and Chron's disease. Finally we analyse the beneficial role of probiotics.
PMID: 21988043 [PubMed - indexed for MEDLINE]
2. Trop Gastroenterol. 2009 Apr-Jun;30(2):76-85.
Probiotic-induced changes in the intestinal epithelium: implications in gastrointestinal disease.
Ramakrishna BS.
Department of Gastrointestinal Sciences, Christian Medical College, Vellore 632004, India. [email protected]
There is resurgent interest in the use of probiotics to maintain gastrointestinal and systemic health, driven by recent advances in knowledge of bacterial interactions with the epithelium and innate immune system of the intestine. The effects of probiotic bacteria on the intestinal epithelium and their downstream consequences are reviewed. Probiotics prevent pathogen adherence and invasion of the epithelium, partly by blocking adherence sites but also by upregulating gene expression of MUC2 and of antimicrobial peptides. Metabolic effects of probiotics on the intestinal epithelium include production of short chain fatty acids which influence epithelial cell metabolism, turnover and apoptosis. Bacterial metabolism of unabsorbed dietary constituents with production of free radicals and phenolic metabolites can lead to DNA damage and cancer; probiotics restore eubiosis and potentially prevent this. Probiotics alter expression and redistribution of tight junction proteins and reduce intestinal permeability limiting absorption of noxious molecules from the gut lumen. Most studied are the effects of probiotics on epithelial cells which are the first line of innate immune-capable cells that encounter luminal flora. Probiotics, through secreted molecules, influence the innate inflammatory response of epithelial cells to stimuli from the gut lumen, and reduce mucosal inflammation. Through effects on dendritic, and possibly epithelial, cells they influence naïve T cells in the lamina propria of the gut and thus influence adaptive immunity. These varied effects of probiotics have implications for the treatment of several gastrointestinal diseases including antibiotic-associated colitis, acute gastroenteritis, inflammatory bowel disease, colon cancer, and irritable bowel syndrome.
PMID: 19760989 [PubMed - indexed for MEDLINE]
3. Inflamm Bowel Dis. 2009 Feb;15(2):300-10.
Mechanisms of action of probiotics: recent advances.
Ng SC, Hart AL, Kamm MA, Stagg AJ, Knight SC.
Antigen Presentation Research Group, Imperial College London, London, UK.
The intestinal microbiota plays a fundamental role in maintaining immune homeostasis. In controlled clinical trials probiotic bacteria have demonstrated a benefit in treating gastrointestinal diseases, including infectious diarrhea in children, recurrent Clostridium difficile-induced infection, and some inflammatory bowel diseases. This evidence has led to the proof of principle that probiotic bacteria can be used as a therapeutic strategy to ameliorate human diseases. The precise mechanisms influencing the crosstalk between the microbe and the host remain unclear but there is growing evidence to suggest that the functioning of the immune system at both a systemic and a mucosal level can be modulated by bacteria in the gut. Recent compelling evidence has demonstrated that manipulating the microbiota can influence the host. Several new mechanisms by which probiotics exert their beneficial effects have been identified and it is now clear that significant differences exist between different probiotic bacterial species and strains; organisms need to be selected in a more rational manner to treat disease. Mechanisms contributing to altered immune function in vivo induced by probiotic bacteria may include modulation of the microbiota itself, improved barrier function with consequent reduction in immune exposure to microbiota, and direct effects of bacteria on different epithelial and immune cell types. These effects are discussed with an emphasis on those organisms that have been used to treat human inflammatory bowel diseases in controlled clinical trials.
PMID: 18626975 [PubMed - indexed for MEDLINE]
4. J Pediatr Gastroenterol Nutr. 2009 Feb;48(2):126-41.
Clinical evidence for immunomodulatory effects of probiotic bacteria.
Ruemmele FM, Bier D, Marteau P, Rechkemmer G, Bourdet-Sicard R, Walker WA, Goulet O.
Department of Pediatrics, Hôpital Necker-Enfants Malades, Paris, France. [email protected]
Close, tightly orchestrated interactions between the intestinal epithelium and the mucosa-associated immune system are critical for normal intestinal absorptive and immunological functions. Recent data indicate that commensal intestinal microbiota represents a major modulator of intestinal homeostasis. This review analyzes the process of intestinal colonization and the interaction of microbiota with the intestinal epithelium and mucosal immune system, with special reference to the first years of extrauterine life. Dysregulation of the symbiotic interaction between intestinal microbiota and the mucosa may result in a pathological condition with potential clinical repercussions. Based on the concept that there is a beneficial and symbiotic relation between the host and endogenous microbiota, strategies aimed at directly modulating intestinal microbiota with regard to disease prevention or treatment have been developed. One strategy involves administering viable probiotic bacteria. Clinical evidence for the beneficial effect of probiotics in the prevention and/or treatment of necrotizing enterocolitis, infectious and antibiotic-associated diarrhea, allergic diseases, and inflammatory bowel disorders is reviewed herein.
PMID: 19179874 [PubMed - indexed for MEDLINE]
5. Crit Rev Clin Lab Sci. 2009;46(1):25-54.
Intestinal bacteria and inflammatory bowel disease.
Macfarlane S, Steed H, Macfarlane GT.
Microbiology and Gut Biology Group, University of Dundee, Dundee, UK. [email protected]
Crohn's disease (CD) and ulcerative colitis (UC) are the two principal forms of inflammatory bowel disease (IBD). Animal studies show that bacteria are involved in the etiology of IBD, and much is now known about the inflammatory processes associated with CD and UC, as well as the underlying genetic, environmental, and lifestyle issues that can affect an individual's predisposition to these diseases. However, while a number of candidate microorganisms have been put forward as causative factors in IBD, the primary etiologic agents are unknown. This review discusses the potential role of luminal and mucosal microbial communities in the etiology of IBD, and outlines studies that have been made using a variety of biotherapeutic therapies, involving the use of antibiotics, probiotics, prebiotics, and synbiotics.
PMID: 19107650 [PubMed - indexed for MEDLINE]
6. Curr Pharm Des. 2009;15(18):2074-86.
The therapeutic impact of manipulating microbiota in inflammatory bowel disease.
Kanauchi O, Mitsuyama K, Andoh A.
Central Laboratories for Frontier Technology, Kirin Holdings Co. Ltd, 1-13-5, ***uura, Kanazawa-ku, Yokohama, 236-0004, Japan. [email protected]
It is well established that intestinal microbiota play an important role in the pathogenesis of inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease. Various methods of altering the composition of intestinal microbiota have been examined. Recent evidence suggests that the administration of select prebiotics, probiotics and synbiotics may improve the clinical outcome of patients with IBD. In addition, IBD patients are well known to carry a higher risk of developing colorectal cancer due to chronic inflammation. Therefore, probiotics and/or prebiotics may be appropriate treatments for prophylactic use due to their physiologic characteristics and lack of obvious toxicity. This review summarizes the current experimental and clinical knowledge about the role of intestinal microbiota in IBD, the prevention of carcinogenesis related to IBD, and its importance as a target for new forms of neutraceutical therapy.
PMID: 19519445 [PubMed - indexed for MEDLINE]
Post Edited (DBwithUC) : 1/4/2012 12:11:07 PM (GMT-7)