Danger in probiotic boosted home made yogurt ? - (Feb/20/2012 )

Hello dear members,

I hope I am not intruding into your field of study with this question coming from a microbiology neophyte. I'm actually a photographer/photo journalist wanna be.

That being said, I'll go ahead with my question anyway, in all its non-scientific glory.

I have been making fermented products (for myself, family and occasionnaly friends) for a while now : miso, shoyu, sauerkraut, yogurt, pickles, etc. Recently, I've been wondering if i could not "boost" my yogurt with more beneficial cultures that you find in the probiotic pills and drinks available in pharmacy and grocery stores. I've been wondering first, if they would survive (i've done the research and i think 6/7 strains would), if they would grow happily during my 8h incubation at 42C, and, mostly, if they would over grow and maybe be harmful to my regular yogurt strains and mostly to myself. Is there a point where too much of those probiotic strains could be harmful to me ? how much can those trains actually multiply during a 8h fermentation at 40-42C ?

To be more specific, i would be using Probaclac, Adults. It has the following strains : Bifidobacterium bifidum, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus rhamnosus, Streptococcus thermophilus.

I was thinking of mixing one pill with my 1 tablespoon of yogurt to innoculate my 1 quart of milk (and some added powdered milk protein).

Does anyone expect a problem ? should i not even try it ? should i try and see if it screws with my digestive tracks ? Can i get my yogurt tested somewhere to see whats in my yogurt after the incubation period ? Should I not post here anymore ?


Thank you very much for your time.

Simon

Lactobacillus rhamnosus==> used in youghurt allready
Streptococcus thermophilus ==> allready being used in yoghurt... so no problem there.
Lactobacillus casei, ==> used in yakult and some yoghurt
Lactobacillus bulgaricus ==> used for yoghurt
Lactobacillus acidophilus, ==> used in yoghurt
Bifidobacterium longum ===> bacteria commenly found in humans, dont think they really use it , maybe as a probiotic?
Bifidobacterium bifidum ==> as as Bifidobacterium longum


So you see.. its nothng "special" ...

I dont know if they will all "work" together to produce "good" yoghurt (and by good I mean taste.., its not that it will make you sick normally.. maybe just some extra "stimumation" or something).

Wether they will survive your proces? I think most of them will, but cant tell for sure. It sounds you have been making yoghurt yourself a while.. so I suppose you know how to make yoghurt and I dont expect big problems.
Its a proces of trail and error and the most important thing is that you make sure you use bacteria that are harmless.. but since you can buy them as probiotics/and they are used to make yoghurt its save to use them.

Maybe you can just try to make yoghurt with 1 or 2 combinations (in stead of buyng this pill?) and make different combinations and select the best one? Or if they are all good, just make different combinations each week... then you can change your yoghurt/bacteria each week.. thats healty too! (no need to put 555555 bacteria in your yoghurt each time, its good to just use 5 this week, 5 others the week after taht, 5 othetrs the week after that etc...

About your specific questions: they survive at 42°C, they multiply etc.. I cant tell really... most will.. but to get more specific/detailed information you need to check the literature or hope that someone here on the forum is specialised in making yoghurt. Its not my area of expertise anyway.

Anyway, the worst that can happen is that they dont survive your yoghurt making process.. but then you just wasted some money buying the pil.. to big problem I guess.

Thanks for the answer.

I got the pills for free from my mother who bought them for a trip in south america and stoped taking it. My usual yogurt starter had 3 strains : bifidobacterium lactis, lactobacillus acidophilus and lactobacillus casei, so from what those probiotic adds, it would add 5 new ones. My thinking is that since i use a tablespoon of my previous batch to start a new one, i would be pretty much growing those 8 strains found in the probiotic into my homemade yogurt.

is that a logical assessment ? if they all survive the incubation (which from reading on them, just as tempereture is concerned, they should), will they multiply and stay alive from batch to batch ? is there a certain point where i would have too much of them in the yogurt, and that it could get me sick ? could they, if there is too many of them in the yogurt, take over all the other beneficial bacterias in my digestive track ?

Thanks alot for your thoughts...i know this aint that much of a yogurt forums, but it seemed a good place to ask.

Simon

All of those species are non-pathogenic, indeed many of them are part of your normal gut flora, and in many instances beneficial for digestion of substances that you can't digest yourself. In theory at least, you could make a culture that has overgrown, but this is unlikely to be harmful to you. You are much more likely to get sick from a yeast or other bacterium contaminant that has grown in your yoghurt.

They should propagate fairly well in your yoghurt, though I am not sure about the bifidobacteria.

You can give it a try, because if the bacteria are still alive they will grow in your yoghurt. Howver I am not fond of all the probiotic stuff etc, because the "special strains" are usually owned by big companies who use their special, not proven health benefits over the usual strains to sell their products with a higher profit. So I think if you use high quality milk your previous protocol to make yoghurt will be as healthy than adding more strains to your protocol.

good to watch: www.bbc.co.uk/worldservice/documentaries/2010/12/101215_food_that_makes_billions.shtml

Yes, i see what you mean and I dont like encouraging big pharmaceutical companies on such products, and i'm fervently against all the patenting linked to natural products and GMO alikes that ends up owning most of the seeds of the world; I think that is the most absurd, twisted and nasty form of capitalism the world has ever seen.
As i said, i took that probiotic free of charge from my mother, and looking at the strains it contains, they looked natural enough for my taste. I use organic whole milk for my yogurt from a local farm, and making my own yogurt weekly has pretty much given me the healthy probiotics most people feel the need to buy off the shelves.

about them being alive...the company claims that they are alive and well, at room temperature, until at least jan 2013.

The whole thought process behind this was to see if i could have a yogurt starter (you use a tablespoon of the previous yogurt batch into the next one you are making) with more strains than usual, taken from probiotic products, and to "cultivate" them from batch to batch. My concerns were to know if indeed they would keep from batch to batch, and also if they might take over and be present in so many billions that it would become harmful for my existing flora.

I made a batch last night using one tablet (says it contains "6 billion active cells"), incubated over night. i'll try the results tonight. Wish i could test it easily see how many are now active in my yogurt, and which strains did survive the ordeal.

Thanks for the info, as always, and thanks for the link. gonna listen to that right now.

Simon

yes I see what you mean. What you did should work - although I expect that one or two strains will dominate your yoghurt anyway, also in your old starter, so it is not granted that the strains you started with are still all in there.
However the fermentation of milk is a process which is very stable and if you have a well working strain and the yoghurt tastes good you are usually on the save side microbiolgically. Also your organic milk might contain some additional cultures that add to the caracter of your product. However good luck, and probably you let us know if your experiment was tastey

so, technically speaking, if a strain or two start to dominate, could it kill the other ones, or would they just be there in larger numbers, and the dominated ones in smaller numbers ?

i know this is getting pretty specific and would require testing, but lets just say generally, how would that work.

Is there a way to get yogurt tested somewhere ?

olothstar on Tue Feb 21 16:47:03 2012 said:

As others allready mentioned: its not so much about "how dangerous" the combination will be (there is no danger), its more about: how will the 6 (or more) strains behave themself all in 1 jar of yoghurt...
Its possible that 1 or 2 or 4 strains will dominate and that after a while you will be left with only 3 strains of the original 6+ you started with.
(and yes, the others will just die or be present in very very low amounts.. its hard to tell, it depends..)

But then again, maybe they are all "fine" being together.. Nobody can tell...

It comes down to this: its safe to do, but if they will all survive? Dont know... Will it taste ok? No idea... Will it be better then the regular yoghurt you make? Dont think so... Might it be intersting to test other combinations? Yeah...
If I was you, I would start making all kinds of yoghurt.. just to see whats the best and to have a mixture of bacteria..
For example: make the yoghurt you allready make, but add the probiotic tablet.. or dont use the yoghurt you have and start all over with the priobiotic itself .. see what the difference is..
Or buy other strains (like the ones in the priobiotic tablet) and try them out in different combinations..

Anyway, thats what I would do if I liked making yoghurt and trying out different things.

There is only one thing to keep in mind: buy the strains in the pharmacy or companies so that you know you are working with the right, save , strains.
Perhaps you can even ask your local dietery farm, where they produce yoghurt, for a strain? Or if they dont want to give the strain, ask them for some yoghurt and ask them what strains they use...
If you really want to.. you can really have fun making all kinds of yoghurts... and if you keep it up, at the end you will have your own personalised yoghurt...

And what do you mean with testing the yoghurt? you mean checking out what strains are in the yoghurt? or just checking if its save to eat?

thanks for the reply. i guess my (and my GF, mainly!) main concern is solved : safe if the source of the strain is safe.

By "testing the yogurt" i mean like bring it to a lab, see which strains are in, and in what proportions. i'd be willing to pay some dollars, but nothing excessive. i'm curious what survives and what doesnt, and if its even worth doing the extra of adding the probiotics. The test i did (and will soon eat) was with probiotic pills (probaclac) which has 7 strains and 6 billions living cells, but i had the idea when i saw another product on the market which had 20 billion per serving or something silly. I just thought it couldnt hurt to add some strains to my homemade yogurt and get more benefits out of it.

Thanks again for everything said here, major help.