There are gut bacteria in the SI as well as the colon. They do different jobs. I signed up for the ZOE thing recently, knowing that it might not work out for me with an ileostomy. Part of this involves giving a pooh sample and they smash it down and identify by DNA all the gut bacteria in your sample. I have zero/ negligible of some (whole) gut bacteria. But I also have some gut bacteria that are normally found in the colon - even though all of mine has gone. I've sent questions about this to the support mentors and nutritionists in ZOE and not had clear answers back. I think they were mainly expecting to be asked questions about recipes making good use of the foods identified as best for me.
It seems it's complex. There will be individual reactions in our bodies.
The ZOE program tests your body's ability to process fats and sugar and looks at the health of your gut bacteria. It puts this together with information you provide like age, BMI, exercise level. It then rates foods into 4 categories which relates to how frequently you should include this food in your diet. Putting meals together you can add foods that take an ‘eat very occasionally food' into a meal that you can have several times a week. So the foods are assessed as to whether they are Ultra Processed Foods - which will not feed the gut bacteria and will probably not be good for people who don't process sugar and/or fat well.
I'm going into all this detail because ZOE is very complex in how it assesses foods against your data. I think that the lack of colon bacteria probably puts a bias on how the App assesses individual foods so that it isn't as useful as it could be. I'm only partway through understanding it.
But - Professor Tim Spector has a book out that covers all the findings that go into ZOE - ‘Food for Life' and I think that might help in understanding gut bacteria, overall. And the book is much much much cheaper than the ZOE program. Generally, Prof Spector's research has found better effects from food sources than from supplements. Recommended are things like live yoghurt and fermented foods like sauerkraut, kimchi, kefir.
As to probiotics, I have BioKult Cyan if my bladder is feeling irritated and that seems to calm things down. Probiotics have different bacteria in them. If they mainly contain bacteria that work in the colon then I don't think that this is going to be useful unless your SI has started to take over some of the functions of the colon. I've read that this can happen - but I don't know if it's true, don't see how that can work and don't know what kind of functions would be included.
I think that the best approach is to look at the end results. Is your SI absorbing nutrition properly. Blood tests can give some information on nutrient levels. Vitamin B12 is the one to watch. And Vitamin K2. I go for liquid forms of supplements, absorbed straight into the bloodstream. Try different brands. How do you feel ? See what affects your energy levels.
The most useful thing for me doing ZOE is that it included me wearing a continuous blood glucose monitor for 2 weeks. I recorded everything I ate and drank on the ZOE app and the glucose monitor came with an app that showed the effect on my blood sugar of eating that food. For me, being able to see a graph of my blood sugar and at the same time notice how the food I'd just eaten made me feel has changed my ability to improve my energy levels. I learn by doing and by seeing - so this is probably why this made such a difference for me. Any of us can buy a continuous blood sugar monitor and pay for a month's subscription to find out about how we respond to carbs and sugars. It's cheaper than ZOE. But ZOE would give a complete reading of what's gut bacteria you have and what is negligible or missing. If you try ZOE I recommend that you take a pooh sample before you eat the test muffins. ZOE is not available for people with Crohns or who have sensitive reactions to certain foods. (There are different reasons for people ending up with a stoma)
This is a long answer - veering off from the original simple question. The reason for this is: why do you think probiotics would help you ? Is there something about how you are feeling, how your body is reacting that has brought this up for you ? Start there and then look into what the solution is to that particular issue. If it's just general anxiety then do something to fix the anxiety. Which might be counselling or it might be gaining knowledge. If you are tired, explore what can cause this. I found that making sure I don''t get dehydrated made a big difference. And then, dealing with sugar spikes. Also, resting when I need to rest.
I hope something here is useful. I don't have any financial link with ZOE. Personally, I'm glad I did it, I'm sorry I spent so much money on it and I am not continuing with it because I can't trust the app to give me accurate assessments. I learned stuff I didn't know before but the information is probably in the book and my blood tests couldn't be processed so my results weren't as individual as they could have been.
If anyone on here has done ZOE I'd be interested to hear how you got on.