This is a subject which I find very interesting as well, and have done a lot of thinking/reading about
. It's very hard to find quality information, as you can read through 3 different websites, all of which will say the exact opposite of the other two. I think most of the information out there w/ respect to this subject is garbage.
But before we talk about
prebiotics, I wanted to mention a couple things first.
Most drs will tell you SIBO and dysbiosis are two separate things. I had one MD tell me they were "two functionally separate" ideas that both cause stomach issues, but other than that, not related. This is wrong. From what I can tell, in most cases, dysbiosis = sibo. This should be obvious to your gastroenterologist, based on their own guidelines, but unfortuantely they are devoid of critical thinking skills. What is the first thing your GI will tell you if you have SIBO? Try following a low-fodmap diet. Fodmaps, by their very definition, are fermentable, and therefore will bypass the small intestine to be fermented in the colon. This in and of itself should tell you that many, if not most, cases of SIBO are driven by large bowel dysbiosis.
A second thing which most people underappreciate is that its often not simple carbs which are the problem. The argument is that simple carbohydrates are what drive sibo. Most simple carbohydres like glucose and sucrose are absorbed immediately in the small intestine. They never make it to the colon to ferment. The exception, is that lactose and fructose, are two simple carbohydrates that many people have trouble breaking down due to low enzyme activity. This is why they are considered FODMAPs as well, even though in theory they should not be "fermentable" but absorbable. Therefore, if you have SIBO, it's possible over-consumption of high fructose corn syrup and/or dairy intolerance (low lactase) are two causes. I'm not saying everyone can absorb every other simple carb, or that table sugar is the best thing for you, just that those other two I mentioned tend more often to be the culprits.
In addition to this, there are certain types of fiber which can cause problems, as these will be fermented in the colon for sure. I know resistant starches like potatoes, oats and rice, or beta glucans in beans and wheat, which are normally touted as healthy for the microbiome, are some of the biggest offenders. These are NOT healthy for someone with SIBO. They will feed both good and bad bacteria, and you likely have a lot of bad guys.
As an aside to this, imho, most digestive enzymes you buy online are garbage. They'll have 30 different enzymes, most of them helping you digest things like protein or fat which most people have no problem with. But you see them an feel cozy. An ideal digestive enzyme for a wide swath of the population, off the top of my head, would contain lactase for lactose, DPP-IV for trace gluten, xylose isomerase for fructose, casein specific endoproteases for casein, and beta glucanase for beta glucans, in addition to maybe a couple other things I'm probably missing. This is generally speaking, of course, as there are smaller portions of the population who have trouble with other things, like fatty stools because of fat intolerance for example.
Now with regards to prebiotics, they are fibers by definition. Fiber is a sugar (or sugar alcohol under some definitions) that is fermentable, which means its not able to be broken down by enzymatic activity, and must be digested by bacteria. Since pre-biotics make it to the colon, they are fiber. But the difference is that to be a pre-biotic, it has to be supported by substantial evidence that it feeds mainly the good bacteria. FODMAPs are sugars (fibers and simple carbs that a person may be lacking an enzyme for) that are digested more rapidly than other types of fiber in the colon. I think that a reasonable rule of thumb is to assume any FODMAP or fiber that is not a pre-biotic will/may feed bad bacteria too. This isn’t to say that fiber is bad, only that it depends on who (and therefore what bacteria) is eating it.
Now as Garzie pointed out, there are conflicting opinions, but I would start here with this podcast. He puts out a lot of good stuff. He's a PhD microbiome researcher who has been doing this research for over 20 years.https://feedmephoebe.com/prebiotics-probiotics-sibo-treatment-jason-hawrelak/
In this podcast he starts off by talking about
the data that shows that an overwhelming percentage of the population deemed to have IBS actually have SIBO (if i remember correctly the data is something like 85%). He then goes to show the data which proves how both pre and pro biotics are overwhelmingly positive for IBS, and therefore SIBO. He then talks about
which types of probiotics are beneficial. As he says, its strain specific, and you want one that does something specific youre trying to accomplish (motility, antimicrobial. William Davis puts out some good info on this as well). He then goes on to talk about
the data on SIBO and pre-biotics. He did a meta-analysis of every study that exists on SIBO and prebiotics, and found, I think, that every single one of them showed pre-biotics as being BENEFICIAL, not harmful, for SIBO sufferers. All of this flies in the face of what we are generally told, if you have SIBO, pro/pre-biotics are like throwing fuel on the fire.
Now for my own experience. Dr Hawrelak loves PHGG. That's his preferred prebiotic. I decided to give it a go when I was off ketosis, and noticed that is had a benefecial effect on my diarrhea even not being in ketosis. So much so that I even recommended it to my father, who has dysbiosis issues as well, and he noted a benefit. He still uses it.
On Hawrelak's recommendation i started making my own L Retueri yogurt as well. It definitely helps and is tasty, but I no longer use it as I'm concerned about
dairy. I need to figure that out first, if it is an issue for me or not.
Now, my nutrionist Mary R seems to be of the same camp. Her theory is that pretty much everyone w/ a central nevous system disease has developed food intolerances and most likely SIBO. She believes that by correcting the microbiome and removing food toxicities, you give the immune and CNS systems a chance to calm down and reset. She likes to start people out on a month of only soup and meat broth to heal the gut lining, and then move to a ketogenic high fat diet to starve the bad guys out. The idea is to keep as inert a diet as possible. She says that the research indicates that bad gut bacteria can go dormant for up to 6m (i was able to verify this), so it takes 6m to permanently change the microbiome. That means ultra strict diet for 9m-1y to be safe. She believes that many types of fiber can feed the bad guys. For example, I cheated about
3m into my diet last time with some starch in the form of oatmeal. She basically told me I had undone 3m of hard work. The bad guys were fed, and I had to start over. I think she is correct.
But in addition to this idea, she does like to use certain prebiotics to feed the good guys. I go by her clinical experience, which is overwhelmingly positive wrt the use of prebiotics, in addition to the data I cited above. Inulin is her preferred pre-biotic. I havent asked her about
PHGG, but she loves loves loves inulin. From what I've read, its more powerful than PHGG. Some people will get loose stools and farting for a few days after starting it, but it will settle down. I've had no problems, and I actually credit prebiotics (im rotating between the inulin/phgg) with being the reason why my stools have completely solidified this time in ketosis vs last time, as I wasnt on either last time.
One word of caution. Every gut is different. Some people really can have an overgrowth of good guys, or they just react differently. As garzie pointed out, the science isnt 100% there, these are only guidelines.
So thats my thinking, and all I got. I hope it was helpful.
Post Edited (dcd2103) : 8/11/2021 1:54:33 PM (GMT-6)