I am just curious as to how effectively certain bacterial strains in
my homemade yoghurt would multiply. I have a condition
called ulcerative colitis and have seen research concerning certain
strains of bacteria being particularly beneficial for colitis, some of
which are contained in the probiotic powder I use to make yoghurt. I
make my own goats milk yoghurt by mixing a probiotic powder to heated
goats milk (once cooled) and then incubating the mix for 24 hrs in a
yoghurt maker. The yoghurt generally works out fine and definitely
agrees with me symptom wise. Each 2 grams of the powder apparently
contains the folowing bacterial strains:
lactobacillus acidophillus 5.3 billion
lactobacillus delbruecki/bulgaricus 30.6 million
lactobacillus rhamnosus 40.8 million
lactobacillus casei 91.8 million
lactibacillus plantarum 3.36 billion
lactobacillus brevis 20.4 million
lactobacillus salivarius 20.4 million
bifidobacterium bifidum 1.326 billion 

My question is whether the different strains would multiply/survive in
the yoghurt with equal efficacy or would certain strains dominate ?
Secondly as the probiotic powder already supposedly contains a large
number of organisms in comparison to normal commercial yoghurt would I
be getting an exceptionally high dose of probiotics through the
consumption of this home made food ? Cheers in advance.

Lactose content affects the growth of atleast L. bulgaricus. The sugar
complexity and content sometimes dictates the way in which they are
metabolized by the bacteria.