This is a long post and this content is also available as accessible audio free on Spotify on the Facts Not Fears podcast: https://podcasters.spotify.com/pod/show/dr-kate-mccann/episodes/Gut-Health-Lets-talk-probiotics–prebiotics–and-antibiotics-e2iarhn

What is gut health?

“Gut health” refers to a healthy, functioning gut that works without pain or symptoms such as diarrhoea or constipation.  However, increasingly this term is [mis]used, especially in wellness marketing, just to refer to the “gut microbiome” or the 50 trillion bacteria (yes, that’s more bacteria in your gut than there are stars in our galaxy!) living in your large intestine, or colon (the part that is near the end of your digestive tract.)  You have around 300-1,000 different types.  Lots of different bacteria is healthy and we call that “microbial diversity”. The bacteria in our gut have important roles to play in our bodies. Some we understand, but lots we don’t.  One important way is absorption and making of some hormones and vitamins.  We know there is a difference in the gut bacteria in men and women.  And the gut bacteria in people with certain diseases and people who are healthy.  And while people with some chronic diseases may have different bacteria or a loss of diversity, it’s still not clear which happened first: did the disease cause the change in bacteria, or does a change in bacteria have a role to play in causing the disease?  This is an area of interesting research.  Other areas of interesting research that “gut-brain axis”, or the communication between the nervous system in our gut and our brain.  Most people are already aware of it, even if they don’t call it that:  Just think of that upset or nervous tummy.  We even say things like “gut feeling”  or “butterflies in your tummy.”   Some of the most interesting research is being done at APC  Microbiome Research based at UCC. Scientists are exploring things like diet-microbe-host interactions, or how the diet and the host(that’s you!) and the microbes (that’s your gut bacteria) all interact.

This week I picked up antibiotics for DH that the dentist had prescribed for him.  Stamped on the bag was a message telling me that the pharmacist recommends probiotics. Are we really doing this now?  I would think that stamps on pharmacy bags should be to remind patient of the really critical stuff:  “contains penicillin” or “avoid alcohol”  or “take with food”.  It’s interesting because there are no approved health claims for probiotics! Got questions?  So did I.  Here’s the Food Safety Authority information. 

Last year, then-preschooler C. had been ill. When I went to the chemist  to pick up C.’s prescription, the assistant asked me if I wanted the chemist to recommend a probiotic.

Now, I was fascinated.  First time I’d even been asked that.

Had there not been a queue of people behind me, I would indeed have loved to ask the chemist the following questions:

1. Is this based on the current various international guidelines for paediatrics that have found some/modest benefit for probiotics for children in certain cases?

2. Is this the result of the large chain pharmacy’s upselling policy –and based more on popular marketing trends then actual science?

   Probiotics and €€€€

   Probiotic market is worth billions, and continuing to grow. The global market is valued at over US$100 billion. Did you know that one-third of the clinical trials done on probiotics are industry-funded?

3. What actual probiotic supplements (dose and species) are being suggested?

As there was a queue of people, I simply collected my child’s prescription. (I have a Blog for musing. I don’t need to be that person in a crowded shop!)

But if money is tight in your house and this is just too much to afford, should you worry?The short answer is no – your child’s (and your) gut microbiome will likely be fine! Especially when we are talking about more commonly prescribed antibiotics used in the community. 

Let’s give you some more information.

The current overall evidence from meta-analysis (meaning when they combine the data from several good quality studies) suggests that there is moderate effect of probiotics for preventing diarrhoea from antibiotics.  The studies found that the benefit from high dose (> 5 billion CFUs per day).  It found that it could reduce the duration of antibiotic-associated diarrhea by almost one day. The benefit was found in particular with 2 species:  Lactobacillus rhamnosus or Saccharomyces boulardii.   How many days is it best to take them for?  Well, studies ranged from days to weeks – so, experts aren’t sure yet. Experts agree while it probably has benefit, it does needs to be confirmed by a large well-designed multi-centered randomized trial.  Those aren’t done yet.  Gut health is a fascinating area of emerging research – and while marketing is jumping in, we certainly don’t have all the answers!

So, while many international guidelines do support use of probiotics, don’t lose sleep if this isn’t something you can afford at the moment.  

What else to know?

If the supplements are a bit pricy (and some are), you can also consider foods that naturally have probiotics, even though most are unlikely to have the dose (measured as CFUs) or species recommended by current research:  Yogurt, Kefir, Sauerkraut, Kimchi, tempeh, miso, buttermilk, cottage cheese, and sourdough! You can choose to start it with the antibiotic, or on the last day of the antibiotic (experts aren’t sure which is best yet!)

Most of the important things that help a happy gut don’t come in a bottle, anyway!  Physical activity, getting outdoors, getting enough sleep, and a healthy diet rich in veggies may help support a healthy gut more than a supplement.  Many veggies are “pre-biotics” or foods that support good gut health and microbiome (think of them as fertiliser for the gut) and include veggies like asparagus, peas, whole grains, bananas, onions, soya, and garlic.

What else to know?  Probiotic and prebiotic supplements are not yet regulated by the HPRA (they aren’t medications). Also, antibiotic-associated diarrhoea is common (and, in studies, was found that it can still happen even if you use probiotics!).  Whether or not diarrhoea does happen, your child’s gut microbiome will usually recover on its own – over 2-4 weeks – on a healthy diet. Antibiotic-associated diarrhoea is one of the important reasons docs recommend avoiding antibiotics unless they are really needed.

Read more from The Lancet editorial on probiotic emerging research.