The Sensitive Gut

Understanding IBS

The unproven case for probiotics in IBS; so could you do it yourself?

Kefir_in_a_glassProbiotics and IBS: it just seems to make so much sense. There are reputedly about 12 trillion bugs in the gut. They are not just there to break down dietary fibre and other unabsorbed sugars and proteins that enter the colon; they interact with the immune system, and the enteric nerves to alter the function of the gut and other organs, even the brain. Not all of them are beneficial; but the harmful bacteria are often kept under control by beneficial species. The population of bacteria in the colon of patients with IBS, the colonic microbiome, is often depleted and unstable, so that harmful bacteria may gain more of a hold and cause the gut to become more permeable and stimulate inflammation.

‘Take the good bugs to get rid of the bad.’ That has been the message of probiotics over the years. It’s a no-brainer, or so it seems. No wonder so many companies have been falling over each other to produce the most effective probiotic. So many clinical trials have been published using different strains of probiotics in different mediums in patients with different symptoms, you would think we would have an clear cut answer, but no; although as a whole, the data seem to support the role of probiotics as a treatment concept, there is no clear winner. Although there is some evidence, often a single double blind randomised control trial, to support most probiotics, there is not the weight of evidence to favour one product over another. Recently Elon Musk,  entrepreneur, who developed the Tesla electric car, suggested that the companies competing to develop electric cars should pool their resources and design the perfect car and support system. This would then establish the concept which they would all benefit from. I recently suggested something similar for probiotics to a leading manufacturer. Needless to say, this suggestion was not treated with enthusiasm.

On theoretical grounds, it seems self evident that a combination of beneficial bacteria with the greatest number of colony forming units, delivered in a nutrient medium, will enable the bacteria to survive passage through the acid medium of the stomach, colonise the large intestine and suppress symptoms, but consistent clinical data are lacking. Many types of probiotics have shown some efficacy and scientists are not entirely certain whether survival is important. Some studies have shown that even denatured or dead bacteria can have a beneficial effect on the immune system, reducing permeability and damping down inflammation.

So the jury is still out. NICE has hedged its bets, advising doctors and dietitians to tell their patients that if they want to try probiotics, they should take it at the recommended dose regime for a month before stopping – early a ringing endorsement.  It seems a near impossible task to find an effective combination of bacteria out of hundreds of different species for the symptoms of a disease as diverse as IBS. IBS is, as I have suggested many times in this blog, an individual illness. What works for one person will not necessarily work for another. The combinations of social and psychological circumstances and physiological and microbiological conditions of IBS are infinitely variable.

The discovery of a more useful probiotic requires more research not a little serendipity. Scientists may need to think ‘out of the box’. Perhaps there is a key anti-inflammatory bacterial species that works in IBS like Faecalobacter Prausnitzii in Crohn’s Disease, perhaps there is a better way of delivering strictly anaerobic species to the gut, perhaps more work needs to be done to investigate the little known micro-environment, adjacent to the colonic mucosa, perhaps highly specific immune or nutritional conditions will favour the growth of certain, as yet unknown, pathogenic species keynote species. It might be that faecal microbial transplant will hold the key. On the other hand, we might achieve some insights by going back to the future.


While listening to BBC Radio 4 recently, my attention was drawn to a programme in which Dr Michael Mosely reported the results of a study in which he compared the effect of a commercially available probiotic, the prebiotic compound inulin, and the natural fermented yoghurt on faecal bacterial diversity. The probiotic had no effect, inulin showed a significant increase in bacteria and the winner was kefir . Now Mosely’s study could hardly be said to be of sufficient quality to count as scientific evidence, but we could do worse that test the efficacy of natural products.

Kefir is an ancient remedy made of milk inoculated with intestinal bacteria originally derived from the intestines of sheep. It is a mixture of yeasts, lactobacilli and other bacteria and forms colonies that resemble small florets of cauliflower and are called kefir grains. To make the drink, leave kefir in milk for 24 hours, by which time, the milk has become viscous rather like yoghurt, then remove the culture and strain to use again in the next batch. That way a new yoghurt can be made every day for about a fortnight or until the culture begins to ‘wear out’. Left for 48 hours of more, the milk may separate into curds and whey, but it is still effective and some people prefer it. The Russians leave the culture in the milk for a shorter time, remove it and top up the milk with fresh milk, whereupon it continues to ferment. Perhaps it was kefir or similar natural products that gave Dr Shirota and others the idea of manufacturing and marketing ‘probiotics’. Essentially, kefir is a multi strain probiotic, now called a polybiotic, suspended in a prebiotic nutrient medium, a polysaccharide called kefiran. The fact that the organisms grow in acid medium, may facilitate their survival during passage through the stomach and their ability to colonise the large intestine.

Was it the consumption of kefir or something like it by people living in the Caucasus mountains in Georgia that enabled them to live to an very advanced age? This was the story that promoted the health giving properties of natural yoghurts until some suggested that the farmers in the Caucasus lied about their age and even faked their birth certificates to avoid being drafted into the army.

Kefir is so easy to make up yourself. It costs just a few dollars or pounds to get a starter pack of Kefir grains, which may last up to a month. You do not need to take Kefir all the time; it can be made up when you need it.  Kefir can be adapted by adding other ingredients such as flax seeds and can be used in a variety of recipes, allowing you to customise your probiotics to suit yourself. Treatments often work better when you feel you can identify with it and feel in control.


Hungin, A. P. S., Mulligan, C., Pot, B., Whorwell, P., Agréus, L., Fracasso, P., … & Winchester, C. (2013). Systematic review: probiotics in the management of lower gastrointestinal symptoms in clinical practice–an evidence‐based international guide. Alimentary pharmacology & therapeutics, 38(8), 864-886.

McKenzie, Y. A., Thompson, J., Gulia, P., & Lomer, M. C. E. (2016). British Dietetic Association systematic review of systematic reviews and evidence‐based practice guidelines for the use of probiotics in the management of irritable bowel syndrome in adults (2016 update). Journal of Human Nutrition and Dietetics, 29(5), 576-592.



One comment on “The unproven case for probiotics in IBS; so could you do it yourself?

  1. Pingback: From High Fibre to Nutritional and Microbial Diversity: Back to the Future | The Sensitive Gut

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This entry was posted on May 28, 2017 by in Probiotics, Uncategorized and tagged , .

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