Aidan:
Hello and welcome to the Ideal Nutrition Podcast. My name is Aidan Muir and I’m here with my co-host Leah Heigl and this is episode 83 where we are talking about whether you should take a probiotic. And obviously this is an interesting topic because there’s so many people talking about it in terms of potential benefits from probiotics and stuff like that. But it is still an area that is a little bit hit and miss, whereas like sometimes they might help, sometimes they might not. It’s hard to know when you should personally be taking a probiotic. So we’re going to go through a little bit of the research and go through some relevant points on when or when you might not want to take a probiotic.
Leah:
Starting off super broad, like how can probiotics potentially help us? It’s such a broad topic because there are so many aspects that probiotics may assist with, but it’s also like that may is very strong. So we’ll get into like the evidence behind some of these, but generally looking at things like IBS symptoms, they may be helpful for specific IBS flare-ups or symptoms. So like when you’re on antibiotics, potentially taking a probiotic alongside it, or when you’re travelling and there is some kind of gut infection potentially.
Mental health is another big one that’s come up recently a lot, potentially body composition, immune function is a big one, but also things like heart health and other conditions such as allergies or eczema and then other bowel conditions so like inflammatory bowel disease they may have some kind of role there as well.
Aidan:
Yeah and we’re going to talk through a lot of those individually because a lot of that list is like stuff where you can see how it could help. But it may or may not help in all of them.
Leah:
Whether the outcomes are there is like to be seen for some of them.
Aidan:
Yeah. As a starting point, firstly, we’re to be talking mostly about probiotics in terms of supplements. Obviously they’re still in food form and stuff like that, but just keeping it simple for this podcast, we’ll be talking about the supplements for probiotics and going down that route, not all probiotics are the same. Keeping it broad as well, starting off with different strains have different functions in the body and different products obviously have different amounts of these strains. In a perfect world, you theoretically should be choosing the ideal strain for your specific situation in terms of condition, what is in your microbiome, all of these things.
But how do you know what is the ideal one for you specifically is a really tough question. Something that I thought about for a long time early in my dietitian career was why is it that not many experts give specific recommendations? Like why aren’t they saying this is what you should look for in a probiotic? As we go through this podcast, you’ll kind of understand why that is the case. But how do know which one you should choose?
One of the biggest challenge on that that I can kind of see is that the research isn’t really at the point where anything is super clear. Don’t misinterpret that to say that we don’t know anything because we do know a decent amount of stuff. But it’s just like we aren’t really at a point that we can be like, this is exactly what you should do. Some studies show benefits, others don’t. But even amongst the studies showing benefits, they’re often using different strains and different dosages.
An example I like to use, unrelated to probiotics, is whey protein, right? Why is it that pretty much all manufacturers call 30 grams of whey protein a serve? And there’s so much research that’s gone into it. Like some of it has been like, okay, let’s get a bunch of people to work out and then give them 10 grams, 20 grams, 30 grams, 40 grams, 50 grams, 60 grams, et cetera, and see what happens. And it seems like muscle protein synthesis peaks roughly after about 30 grams.
And then there’s also the commercial side of things where they’re like, well, what would people actually want to do anyway? Like if 90 grams is the ideal dosage, that would be a hard sell. Yeah. So it’s like a combination of all these things. Yeah. But if we have like, I don’t know, 10 studies on a subject for probiotics and they’re all using varying strains and dosages and stuff like that, how do we know what the optimal protocol is? Because even if we found a strain that shows benefit how do we know that if you didn’t double the dosage, it would be even more effective? So we know a little bit, but there’s still a lot more questions and answers.
Leah:
Yeah. And there’s so many strains of probiotics. Like we’re going to have to have a really big breadth of research to have that understanding. So it’s going to be, I think it’s going to be a little while away before we have any kind of hard outcomes. But the kind of area of research that we know the most about when it comes to probiotics would be looking at IBS symptoms. So it is definitely the most studied area of probiotic research. A 2016 review on probiotics and IBS found that 29 studies that were assessed, like only 14 showed improvements. So only 14 out of 29 in this review showed kind of a positive result. So already we’re down to like a 50% success rate there. It’s a really mixed bag.
And the ones not showing improvement did not show it to be detrimental. So like at the end of the day, like you can take a probiotic and if it helps, awesome. But if it doesn’t, you’re also not losing anything.
Aidan:
It’s just the money and time.
Leah:
Just the money and time. I mean, probiotics are kind of expensive. So I always factor that in when I am talking to clients. like, you are looking at like potentially like $40 a month. Like I think that’s pretty expensive for most probiotics. So, but outside of that safety wise, you know, they’re safe, they don’t have many side effects. So it’s like one of those things like try it. If it doesn’t work after a few months, then you can probably stop it. But looking within those positive results, the improvements were also not like super consistent. So one of the most promising studies found that 78% of participants reported that the probiotic improved symptoms. But that means that 22% literally noticed no difference. So almost like a quarter of that study, the people taking those probiotics had no positive effect from it.
Another study found that 47% of patients in the intervention group reported adequate symptom relief, whereas only 11% in the placebo group reported that. So that’s enough to suggest that it works, but it still means that there’s quite a large amount of that intervention group that didn’t experience a positive benefit or reduction in IBS symptoms from that supplementation. And out of like those 14 studies that did show positive improvements, 10 noticeably different probiotics were used. So I think that’s key in like 10 different kinds of probiotics were used within that. So like how could we possibly know like specific strains, dosages and everything based on that?
Aidan:
Yeah, I remember reading that and being like that’s why people aren’t giving specific recommendations.
Leah:
You’re like, is why we don’t have like clear cut like protocols for probiotics because we’re using so many different probiotics, dosages, et cetera.
Aidan:
Yeah. And like often people might give like stuff like look for products that contain lactobacillus and stuff like that. Like they might say like a kind of strain and they might say a number of colony forming units, like over a billion colony forming units is a pretty common recommendation but they won’t go much more specific than that.
Leah:
Totally.
Aidan:
So yeah, from the negative perspective, it’s hard to determine what the optimal protocol is, but looking at it from a really optimistic perspective, it’s kind of like, if we’re getting some good results from this, like it’s hitting this with some good results, imagine in 20 years, like if more research comes out, which it will. Surely we can get even better results than we’re currently getting.
Leah:
I think there’s something there for sure, especially when it comes to IBS symptoms or particular reasons why IBS symptoms are occurring. That could probably play a role, but I think there’s something there. just like not at a point where we can give specifics.
Aidan:
The next topic we’re talking about is mental health. So we know that diet and gut health play a huge role in mental health. We’ve seen this through dietary interventions. I’ve talked about it on here before, I assume, but the SMILES trial, for example, and there’s quite a few other protocols that we see huge benefits from. They raise a lot of questions though, because it’s kind of like, although the authors might speculate that the improvements are due to changes in gut health and bacteria in the large intestine and stuff like that, what if it’s due to other reasons? What if, for example, they’re changing your diet and then changing your habits and everything like that has a carryover effect to all these things. Quite complex obviously, there’s a lot of variables but that’s one proposed kind of mechanism.
But we still know that there is something going on in the gut brain access and it makes sense to look at probiotics as well. A 27 systematic review looked at this question. It looked on whether probiotics helped with depression, anxiety or cognition. And it found 10 relevant studies on depression and anxiety and identified positive results in all three of those areas. So it’s pretty compelling, but going through that systematic review all those studies were pretty small, none of them were overly like overly game-changing super convincing studies individually. It’s just because you put them together it looks a little bit better and they once again fit that same theme of using a variety of different strains as well.
Leah:
Another aspect of probiotic research would be looking at immune function. So probiotics can probably or maybe help immune function through a variety of mechanisms. I think like this is quite complex. So in terms of simplifying it, ways that it could help include interactions with immune cells, improving intestinal barriers through tight junctions in the intestinal wall. So this kind of refers to that leaky gut concept, which is probably a whole other topic for a whole other podcast, but there’s potentially something there. Suppressing pathogenic bacteria and improving T cell activation.
It’s pretty complex in how probiotics could potentially have a flow-on effect to immune function. And the list of mechanisms is like, it’s pretty extensive. It’s like very like complex. So we won’t take you down that route too much. Cause at the end of the day, what we really care about is the outcomes anyway.
Aidan:
I think the mechanisms just useful for understanding. like I remember reading research showing that it improved upper respiratory tract infections. reduces the frequency and duration of that in athletes who are over training. I’m like, that’s so interesting.
Leah:
How does it do?
Aidan:
How does it do it? And it’s just like the mechanism kind of makes sense once you go down that rabbit hole.
Leah:
Totally. So it’s definitely worth knowing. But like, again, outcomes is kind of what we want to focus on. There are a bunch of studies showing small reductions in the frequency, like you said, of the upper respiratory tract infections. But that predominantly is in athletes who were intentionally over training.
So in that context, if you’re an athlete who is over training, taking this and then potentially reducing the risk of you getting sick can just lead to you not having to take time off. So I think as an athlete, that could be worth your time in looking into if that’s something you’re experiencing. But there was also some research in children in daycares. reducing, again, the risk of catching a cold or flu and other things like that where it could potentially be beneficial.
Aidan:
Yeah, it seems to be like those higher-risk cases, and I wonder if it’s just because it’s more sensitive, it’s easier to pick it up because, like, at daycare, you’re more likely to get sick, athletes, you’re more likely to get sick. Looking like when you’re with a high training volume, something that I noticed that I didn’t see many other people talking about, but like the studies that were done in winter, it seemed to notice a larger effect. Interesting. I’m just wondering if it’s just because people are more likely to get sick, so it’s easier to pick up the difference.
The next topic we’ll go through is inflammatory bowel disease. This is interesting to me because it’s kind of an area where it’s clear diet plays a role and stuff like that. It’s clear there’s heaps of things we can do to help. But like there’s also a lot of cases that even with the best dietary interventions that we have available, it’s still going to be pretty horrific. Like it’s kind of a, it’s kind of a difficult situation. And it seems like an area where there is a lot of potential, potential wins, but it’s hard to go through.
So looking at Crohn’s and ulcerative colitis, there are clearly changes in the bacteria in the large intestine. In particular, there are decreases in bifidobacterium and lactobacillus, as well as increases in pathogenic bacteria. That sounds really promising because it’s kind of like, well, couldn’t we just supplement Bifidobacterium and Lactobacillus and improve it? Like the mechanism makes sense, but I’ll talk to that a little bit more as well. Another thing that makes it look even more promising is that intestinal lesions in inflammatory bowel disease typically occur in areas with the highest pathogenic bacterial concentration. We know that when you supplement with probiotics, often it reduces the pathogenic bacteria as well. So once again, that sounds really promising.
And it is also proposed that that abnormal interaction between the intestinal immune system and that pathogenic bacteria triggers inflammatory response as well. And a final thing that kind of makes it look even more promising is that when people are in remission, their levels of good bacteria are typically higher than when the disease is active too. So like mechanistically, it looks like there’s huge potential there. You could say that simply using a probiotic high in those two strains, like Bifidobacterium or Lactobacillus, would make sense.
The research is a little bit underwhelming even though the mechanism seems so strong. Going straight to another systematic review, but there was a systematic review just on probiotics and inflammatory bowel disease. And the conclusion was just that available evidence supports the role for probiotics in mild to moderate ulcerative colitis, but not in Crohn’s. That makes a little bit of sense because it’s kind of like what ulcerative colitis involves the large intestine. Crohn’s may or may not involve that.
If something’s in the large intestine, that’s where the probiotics are really doing their job because their highest concentration is in the large intestine. I wouldn’t really 100% rule out any potential benefits in Crohn’s. It seems promising for ulcerative colitis in mild to moderate cases. It’s not something that is like a saviour. It’s not something that’s 100% gonna solve it or anything like that. It’s something that’s worth looking into, but it’s still a bit hit and miss as well.
Leah:
So going through a couple of like just some ones where the research really isn’t as, I guess, exciting or enticing and just kind of going through those pretty briefly. So the first thing would be body composition. So although there are clearly changes in the gut microbiome between those who are lean and those who are obese, it’s kind of like the chicken or the egg scenario for me. It’s like, we know that there are gut health changes between people who are lean and people who are overweight, but whether or not like taking a probiotic would then lead to better body composition outcomes, I’d say like based on kind of what we know so far, I’d say probably not.
On average, there is a small improvement in fat loss in comparison to placebo when we’re looking at the bit of research we have looking at probiotic supplementation in the area of weight loss, but it does seem to be less than 1% in terms of body fat percentage. So, I’d say it’s pretty much irrelevant. And I think there’s probably more of a link between having a healthy body fat percentage and that having a flow and impact to gut health rather than having some kind of role of probiotics in body composition changes and outcomes.
Second one would be heart health. So probiotics have consistent evidence that they can reduce cholesterol and blood pressure by a little bit. I’d say, again, there’s generally other stuff you can do that is going to have way more of an effect in that regard, but there is some evidence. But there’s also not a lot of direct evidence suggesting that probiotic supplementation is going to reduce your risk of cardiovascular disease.
But it kind of makes sense that there might be some flow on effect if you’re reducing your cholesterol and your blood pressure through that. And final thing would be looking at eczema and allergies. I think like in practice, I get asked about probiotics and eczema a lot. I don’t know if that’s something that comes up for you much. No, I feel like, I don’t know, maybe it’s the area that I work in, but I feel like I get that question all the time. And I, my general kind of go to is just like, look, the research is pretty mixed at best. It probably isn’t going to help, but like if you want to try it, go ahead.
Aidan:
Yeah, because it hasn’t come up a lot for me when I was like doing stuff in prep for this podcast. I was looking at that and I went into a very open-minded, maybe, like maybe you can.
Leah:
Yeah, yeah, same.
Aidan:
And then, yeah, it just didn’t seem that interesting when I went down there. It looks super mixed.
Leah:
It’s super mixed. there was like, I had looked at it a couple of times for certain clients and I’m like, look, there just doesn’t seem to be much there going on that looks enticing.
Aidan:
Yeah. So as a bit of a summary, Probiotics, as you can tell, can have some benefits. They are still a hit-and-miss, as we’ve kind of said. In my opinion, they’re worthwhile if you have spare money, interest in taking them and have a condition that could potentially benefit from them. I think that last one is a relevant point because if you’re healthy, feeling good, no issues, I probably wouldn’t add a probiotic in, but if had a condition that might benefit from it, then based on those other criteria of having money, interest, et cetera, it might be worth looking at it.
And a gold standard kind of approach I’ve seen other people talk about, which I kind of agree with a little bit in terms of how to take them, is simply to pick one, ideally, pick one that has some strains in it that the research has shown could be beneficial for that kind of condition and has a decent amount of colony forming units. If you look at probiotics, they’re pretty much all gonna meet that criteria in terms of having enough colony-forming units. But you pick one and take it for about 12 weeks. If it helps, continue. If it doesn’t, either discontinue or try a different one.
The only reason why I’m like, kind of agree with this and not 100% agree with this is because of how I look at other supplements. For example, creatine. I recommend creatine to a lot of people. I’ve personally taken creatine. I could never tell you if I’m on creatine or not. Not on creatine. Like I don’t notice a difference in my strength or whatever, but the research is so good on creatine that I’m gonna take it regardless.
And I kind of see that a little bit of probiotics as well being like, yes, I do agree with that, try for 12 weeks to see if it helps, et cetera. But there is still a little bit of me being like, well, if I had heaps of money, heaps of interest, whatever, even if I didn’t notice a huge difference, I’d probably still consider taking it.
Leah:
This has been episode 83 of the Ideal Nutrition Podcast. If you could leave a rating or review, that would be always greatly appreciated. But other than that, thanks for tuning in.