So, you’ve come around to the idea that “All health starts in the gut” and have decided to take the plunge and invest in gut health supplements. But where to begin? You’ve likely heard of probiotics, but what about prebiotics? Which one is the better choice, or should you go for both? Let’s break this down…
Prebiotics are defined as “a substrate that is selectively utilised by host microorganisms conferring a health benefit.”  What they’re saying here is that prebiotics (the substrate) are used by probiotics (the microorganisms) to make you healthier.
A classic example of this is prebiotic fibre. People usually imagine that fibre goes in the mouth, sweeps its way through your intestines, and then launches out the other side in the form of a bowel movement torpedo. And this is true for some types of fibre, specifically insoluble fibre.
But there’s this other form of fibre called soluble, because it dissolves in liquid, that is totally different. Soluble fibre is actually consumed by the healthy bacteria that live in your colon. This is their food! When you feed them, they’re happy, and they reward you by transforming this fibre into my favorite thing in all of nutrition – short chain fatty acids.
Short chain fatty acids are quite remarkable, particularly when you consider the 21st century epidemics we face. They heal the gut lining, correct “leaky gut” (or increased intestinal permeability), promote the growth of the good bacteria and suppress the bad bacteria, and have an anti-inflammatory effect. And that’s just in the gut. They also optimize our immune system, lower cholesterol, prevent type 2 diabetes… I could keep going. They communicate far beyond the walls of our gut, even crossing the blood brain barrier. The bottom line is that short chain fatty acids are healing, and we get them from prebiotic fibre. 
The beautiful thing about prebiotics is that they take your innate gut microbes and make them stronger. So, no matter who you are, you can benefit from prebiotics provided you follow this one and only rule. Start low and go slow. If you take too much too fast, your gut isn’t given enough time to adapt and you can develop digestive distress. So, whether you’re getting your prebiotics from a wholefood source (ideal) or a supplement (still helpful), you want to ease your gut into it.
What About Probiotics?
Probiotics are live microorganisms – generally bacteria and/or yeast. But they’re not just any old live microorganisms. By definition, probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.  The theory with probiotics is that they mimic the effects of our intact microbiota. In other words, just like our healthy gut microbes these probiotics should optimize our immune system, reduce inflammation, inhibit the growth of pathogenic bacteria, correct leaky gut and restore gut barrier integrity, reestablish intestinal motility, even improve mood. 
So, let me get this out of the way right off the bat. The hype of probiotics is outpacing the science big time. You have to understand, probiotics are all the hotness because it’s (sadly) what everyone wants – a new pill that’s cutting edge, ideally natural, that’ll require zero effort and fix all your problems. Well I hate to burst your bubble, but you can’t fix a bad diet with a probiotic.
But now that I have that out of the way, let me say that there is a role for probiotics, and I’ve had hundreds if not thousands of patients that I’ve treated with probiotics and seen them improve. Some specific conditions that I’ve had success include diarrhea, constipation, irritable bowel syndrome, gas and bloating, ulcerative colitis, pouchitis. There’s a long list of other conditions that have been studied with probiotics, many outside the gut, that’s beyond the scope of this article. Just know that the results are never consistently strong and positive with probiotics.
Often times some people benefit from them while others will not. Why? It likely has to do with the unique nature of your personal gut microbiome. You see, your gut has a mix of bacteria that’s entirely unique to you. As unique as your fingerprint. So, when you introduce a new group of bacteria, you’re crossing your fingers and hoping they’ll fit in with your clique. If they do, and they help your gut to function better, then you will see a health benefit. But if it’s not a fit, then the probiotic accomplishes nothing for you. And this is why our use of probiotics at this point in time is about trial and error. Just because one failed doesn’t mean they all fail. But finding the right one for you is the real challenge.
So How Should We Use Prebiotics and Probiotics?
Diet comes first… always. A couple milligrams of medicine will never overcome the 35 tonnes of food you eat during your lifetime. And neither will a couple trillion bacteria or a supplement! The best supplement is always to get it from your diet. But when we’re looking to restore gut health that’s when you consider adding in prebiotics and probiotics to get things (like short chain fatty acids) working in your favour. Interesting enough, when you combine prebiotics with probiotics, we have a new word for it – synbiotics. Yes, that’s really what we call it and not just me trying to be nerdy cool.
So, in my mind there’s a hierarchy. Diet and lifestyle should come first. Then you consider adding in a prebiotic, starting low and going slow. If needed, you may find synergy by adding in a probiotic as well (getting those synbiotics going). The probiotic should be used to address a specific health goal, and if you aren’t finding improvement in that health goal you may want to try a different probiotic because at the end of the day it’s about finding the one that works best with your unique gut microbiome!
Featured Image Source: www.justinfantl.com
 Nature Reviews Gastroenterology & Hepatology volume 14, pages 491–502 (2017)
 Front Microbiol. 2016; 7: 185
 Nature Reviews Gastroenterology & Hepatology volume 11, pages 506–514 (2014)
 Clin Gastro Hep January 2019Volume 17, Issue 2, Pages 333–344