Part 8 – Probiotics and prebiotics



Probiotics are beneficial live microorganisms that we can eat to improve our health. As far as we know, they don’t necessarily take up residence in our gut but can give us benefits as they pass through.

There are two ways to consume probiotics, either from fermented foods or from probiotic supplements. We don’t yet know if probiotics in food (albeit much cheaper) are better than probiotic supplements, or vice versa.

Current objective opinion is that for healthy people, probiotic supplements don’t significantly change the microbiome, but in ill health or disease they can help restore a healthier microbiome.

Summary analyses of hundreds of trials has showed substantial evidence for the benefit of probiotics for treating diarrhoea; constipation; acute upper respiratory tract infections; eczema and dermatitis in children, improving metabolism; lowering cholesterol; reducing infection rates; and lowering markers of inflammation, like C-reactive protein. Promising research is underway regarding benefit for neurological, mood and brain disorders.

The business of probiotic supplements is currently exploding.  Companies are now making targeted probiotics with specific species and strains of bacteria for a specific problem (like a urinary tract infection), or a specific symptom (like diarrhoea) or specific groups of people (women, children, or elderly). We are beginning to understand which combinations of species of microorganisms are most helpful for specific conditions, but much more independent research is still needed (that is, research not funded by the companies selling the supplements).

Here are some of the species you may see and some of the symptoms or conditions they have already been found to be beneficial for. Don’t be put off by the long names, they are quite phonetically pronounced!

  • Lactobacillus Rhamnosus for eczema, diarrhoea and stress
  • Lactobacillus Plantarum for immunity, lowering gut inflammation and IBS
  • Lactobacillus Casei for diarrhoea, constipation, anxiety and depression
  • Lactobacillus acidophilus for reducing gut inflammation
  • Bifidobacteria Lactis – for abdominal symptoms, supporting immunity, weight control and constipation
  • Bifidobacteria Longum – for constipation, lowering stress and improving memory
  • Bifidobacteria Bifidum – is anti-bacterial and helps the symptoms of IBS and ulcerative colitis
  • Bifidobacteria Breve – for constipation in children, improving skin youthfulness
  • Streptococcus Thermophilus – is anti-bacterial and improves skin youthfulness
  • Saccharyomyces boulardii – This is a beneficial yeast. It out-competes unbeneficial yeasts. It can be taken alongside antibiotics to protect against loss of beneficial microbes. It supports good overall immune function

Supplements should list the quantity of colony forming units (CFU’s) on the packet. Start with 5 billion CFU’s (or lower if you need to) and build up to 50 billion or more, monitoring progress as you go. Stop at the level that works for you. If you experience gas, bloating, constipation or loose stool, reduce your intake and then build up more slowly. Generally speaking, the more severe your gut symptoms the higher the dose you will need to take. For example, VSL#3 is the brand containing the most CFU’s with 450 billion in a single dose! It is available online, but you should seek professional opinion if you think you may need this one! Probiotics are safe but seek advice if you are immuno-compromised.

Be prepared to change brands regularly to maximise the number of different species you are taking. Take probiotics with small meals, for better survival rates. You may need them at every meal. Morning is best to improve your digestion for the day, evening would be better for improving relaxation for sleep. Check expiration dates and storage instructions, some need refrigeration, others don’t. Check for other ingredients like lactose, binders and fillers, like corn starch. Check that the product hasn’t been cooked or heated above 40 degrees because this would kill the bacteria.

Not all probiotics bought online, or in supermarkets are rigorously tested to ensure that they survive transit through the gut. Many brands haven’t undergone strict quality control measures. Look carefully at your packaging and any company research available. You get what you pay for, don’t be tempted to buy low cost.

If you are taking antibiotics and want to take probiotics, take the probiotics as far apart in time from the antibiotics as you can, for example take the antibiotics in the morning and the probiotics in the evening. Continue to take the probiotics after you have stopped the antibiotics. Do not take both at the same time, as both will likely negate the benefits of each other! Probiotics are not a magic bullet that simply wipe out the collateral damage caused by antibiotics. Microbiome rebuilding takes time, there is no quick fix. Bringing the right species to the right area of the body is key to improvement.

If you are unsure, seek professional advice when choosing probiotics, as nutritional professionals have a far wider availability of professional brands available to them, than can be bought over the counter. Similarly, as new research becomes available, professionals are able to match probiotic strains more accurately with a person’s problem. Naturally, as a trained and qualified, practising Nutritional Therapist, I can help you with this, so give me a shout if you have any questions or need any advice.



Prebiotics are carbohydrates from plant fibres. We can’t digest these fibre, but our gut microbes can, so in essence prebiotics are “food for the microbes”.

Prebiotic fibre helps the beneficial microbes to grow; provides food for our intestinal cells; helps digestion; reduces inflammation; reduces insulin; reduces cholesterol and reduces the risk of colon cancer.

Foods high in prebiotics are beans, lentils, legumes, dandelion greens, oats, green bananas, Jerusalem artichokes, asparagus, garlic, leeks, onions, nuts, barley, apples, cocoa, flaxseeds, Burdock root (looks like long brown carrots), Yacon root (looks like a long sweet potato), Jicama root (looks like a potato), and seaweeds.

You can also buy prebiotics fibre supplements such as inulin, Fructooligosaccharides (FOS) chicory root, psyllium husk and fructans. Remember to “start low and go slow” – build up gradually.

Have you heard of resistant starch? This is another type of prebiotic food. It is found in potatoes, rice and pasta when you eat it after it has been cooked and then cooled. So enjoy a little of your cold left-over potato, rice or gluten-free pasta.

Coming tomorrow, Part 9 of this series, looking at optimising your own personal microbiome. Keep an eye on your inbox, and see you tomorrow!

3 thoughts on “Part 8 – Probiotics and prebiotics

  1. Reblogged this on Mother Nature's Diet and commented:
    Continuing in our 10-part mini-series looking at the human microbiome and gut health, today Dawn explains the difference between PRObiotics and PREbiotics, and the role of both in your health.
    With diet tips and some guidance on supplements, read on to learn what you need to know…

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