Scant evidence for claims on the benefits of probiotics and prebiotics

Scant evidence for claims on the benefits of probiotics and prebiotics

That your gut bacteria are critical in maintaining your health is well established. But we don’t know which bacteria are helpful and how they act. Until these questions are answered, probiotics and by extension prebiotics will struggle to fulfil their claimed promises." Paul Bertrand, Senior Lecturer in School of Medical Sciences, Andrew Ball, Professor of Environmental Microbiology and Kate Polglaze, Associate Lecturer in Pharmaceutical Science, all at RMIT University, Melbourne, Australia, explain how probiotics and prebiotics are supposed to work and why claims of their benefits are falling foul of product labelling law in the European Union and Australia:

Given CLL patients are likely to require antibiotic treatment more frequently than average (and which is known to disrupt our gut bacteria) , it would be good to see more research identifying what probiotics and prebiotics are indeed helpful and to what extent.


Photo: Sprouting barley head after summer rain

Last edited by

8 Replies

  • There are thousands of papers on probiotics on PubMed now, most of them recent. An explosion. The science of it all is pretty young, though.

    I took a MOOC (Massively Open Online Class) given by the University of Colorado through last autumn - Gut Check: Exploring Your Microbiome:

    It doesn't seem to be scheduled yet for a 2nd session. That university seems to be the center of the whole (I won't say it) movement. The course was not very technical.

    I also participated in the American Gut Project 2 years ago, and have a nice little chart showing rough proportions of a few families of bacteria and archaea, which tells me very little. But I like crowd sourced science, and I'd do it again.

    Trials take time, and the ones that have been done have been hasty, I think. It's impossible to do in vitro studies (petri dish). Studies based on mice may not apply - different diet, different immune system, different biome. But principles may be similar. Studies have to monitor not only the biome (and is poop a good enough proxy for the whole digestive system?), but also diet.

    I just found this YouTube playlist from the NIH from an online course on Probiotics and the Microbiome given in 2013 by Patricia Hibberd, M.D., Ph.D., professor of pediatrics at Harvard Medical School, and chief of the Division of Global Health at Massachusetts General Hospital for Children, as well as professor of global health at Harvard School of Public Health. But she's a Brit, and I found her delivery entertaining - though she may not have intended that.

    FDA is indeed concerned about immunocompromised people, and even the elderly. Some probiotics are helpful, or at least not harmful for antibiotic induced diarrhea in otherwise healthy people. Quality control and regulation in America is lacking.


  • Thanks for that informative reply on what's happening in the USA Seymour. I neglected to mention in my original post that because we have compromised immune systems, while probiotic bacteria may be proven safe for the general public, they may not be safe for us - particularly if our immune compromise is significant. Thanks Chris, for referring to your earlier post on the potential dangers probiotics may pose for us.


  • Probiotic sepsis, certainly in end stage CLL can be fatal... there is very little research on this...

    It amazes me CLL patients go around wearing face masks in public, wiping themselves continuously with alcohol hand cleansers, then pop a handful of pre and probiotics, chassed with a yogurt drink...

    Bacteria is bacteria... and sometimes 'good' bacteria goes bad... and you get sick and maybe die... friends of mine have... bacteremia sepsis is extremely serious but very hard to prove probiotic causality... the body simply is overtaken with bacteria...

    I researched this 6 months are some links

  • I use to take the probiotic drinks, one reason was because some of them included Vit D, but was advised by my nurse that I shouldn't be taking them. Again the reason given was the same as above, with a compromised immune system adding a bacteria could cause extra problems.

    It's always so hard to know what is best to do, but for me, anything I can do to lower my risk of any infection /problem sounds like a good idea.

    Louise :)

  • Hi Neil,

    The fact is that we can't help but have bacteria of many strains living with us, for good or ill. I have always taken pro/pre-biotics in the form of yogurt, kefir, cheese and in capsule form. I suspended capsule concentrated probiotics during and for awhile after Chemo/mAb therapy which left me very vulnerable to infections. I would rather be introducing what are generally thought to be beneficial bacteria into my system than to chance the proliferation of bad bacteria. Much of maintaining a "good" microbiome is dependent on our choices of nutrient intake. A heavy meat diet for example will maintain a different bacterial makeup to one's microbiome than a vegetarian diet. The question is "Am I being stupid for doing so?" My answer is that we are all different and for those patients with IBS Irritable Bowel Syndrome, colitis, or any evidence of severe immune dysfunction on a level of requiring IVIG the taking of probiotics would be very much more risky and maybe better managed through the type of nutrient intake. It is well to recognize the irony in the fact that healthy immune function for CLLers may well in part be dependent on the right kind of gut bacteria. It is not a black and white argument as to whether or not we or a knowledgeable doctor could improve our health by attempts at improving our microbiome. I will concede that we do not have sufficient knowledge to insure the success at any attempts to do so.

    Seymour is correct that there is now scientific recognition and efforts to better get a handle on the role of the microbiome not only for physical but mental health as well. I will look into the Univ. of Colorado's number 2 :) if they have another. (you started it Seymour) I have been interested in this subject for quite some time now. Every time we take antibiotics and especially broad-spectrum antibiotics we are wiping out much gut fauna. At these times I am more careful to eat even less sugar and fats than I usually do in hopes of providing a more favorable ambient gut habitat for good bacteria. This is far from an exact science and more about what I have read on what "good" or "bad" bacteria like to eat.

    Here are a few related links:

    Progress in the mapping dept.

    mechanistic interest. and this one on inflammation though the context of parasitic worms is not very relevant to western world CLL.

    In my personal way of evaluating a subject like pro/pre-biotics is to size up your own individual situation with as much evidence as you can then go with your gut.


  • Wayne, I too feel that there is much to be gained by better understanding our relationship with that part of our body that is 10 times larger in number than cells with our DNA. And that's from the perspective of someone with IBS who nearly died (well before CLL days) from bad, penicillin resistant bacteria running amok after protective good bacteria were wiped out by a dose or two of amoxycillin for an ear infection. (High strength IV antibiotic treatment a year earlier for peritonitis from a burst appendix left me with gut flora that included antibiotic resistant bad bacteria that gave me near fatal pseudo membraneous colitis). So while antibiotics save my life years ago, I'm now in the unenviable situation of living with a severely compromised immune system thanks to CLL and with a limited range of antibiotics that I can take to deal with infections I can no longer fight.

    Despite living with neutropenia oscillating between stage 3 and stage 4, I seem to be able to tolerate yoghurt containing probiotic bacteria (though I don't eat it if I know my neutropenia is particularly bad).

    I'd definitely advise caution to any later stage CLL patient tempted to try probiotics, particularly if they are neutropenic, at least until the science is in, and given our heterogeneity, even then.


  • Totally unrelated to probiotics and CLL, there's exciting promise that a specific probiotic treatment can help children with peanut allergy overcome that allergy in the majority of cases:

  • The Microbiome and Stress: Relevance to Irritable Bowel Syndrome:

    'Gut microbiota profiles are distinct between individuals and evolve over one's lifetime, particularly during periods of high stress. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, ensuing in the subsequent release of corticotropin-releasing hormone, adrenocorticotopic hormone and cortisol.

    HPA axis activation allows for an adaptive response alerting the organism of noxious stimuli. Its chronic activation, however, results in maladaptive changes at the cellular, structural, functional, and microbial levels, the latter resulting in microbial dysbacteriosis - the imbalance and/or impairment of gut microbiota – and thus affecting the gut-brain axis.':

    There's more interesting discussion on Irritable Bowel Syndrome here:


You may also like...