I'm one of those who adds yogurt occasionally. Personally if it's bad for them I don't have a problem not feeding it (it just means all the more for me because it's so damn nice!), but I have also seen it benefit a hand reared joey! My little Lily developed very bad diarrohea while I was hand rearing her, giving her a tiny bit of live yogurt was my first initial thought which I did also check with a friend and I found it did help.
I would like to see more evidence of this as my suggies do love their yogurt (does this go for yogurt drops too? - I hope not they'd gang up on me and torture me if they didn't get their yoggie drops!), and while I know suggies are not humans - do we have different bacteria in the gut? Is it because suggies have an enlarged caecum?
Wow, whilst researching moggy nosh ingredients, I found this:
"Yoghurt is sometimes used for therapy of chronic diarrhoea in the mistaken belief that the bacteria contained in yoghurt (Lactobacillus acidophilius or Lactobacillus bulgaricus) will colonise the bowel and displace unfavourable bacteria.
Yoghurt has bacteriocidal properties in vitro (test tube) but not in vivo (in the body). Orally administered bacteria in yoghurt does not displace resident or pathogenic bacterial populations in normal or diseased intestines of any animal. The bacteria in yoghurt are generally acid labile (destroyed by the stomach acid), limiting the numbers surviving passage through the stomach. (Research originally published in the Journal of Small Animal Practice Vol. 35)."
Taken from
http://www.burns-pet-nutrition.co.uk/Articles/understanding_pet_food_labels.htm