I'll leave you to research opinions of glucosamine on the net yourself, but it is a simple "sugar" and is believed to be directly vailable to cells and often used in its sulphate form with chondroitin and MSM.
As for Acidophilus, the idea of benign or harmless bacteria in the gut is just taking up all the spaces that bad bugs could invade if they were not already occupied. There are also positive advantages with some bacteria and all info is out there if you look.
The basics of benign bacteria is that ALL acid-tolerant and salt (chloride)-tolerant bacteria are benign.
There is one exception - botulism.
We have an acidic, chloride-filled gut which kills most things except acidopholus, lactobaccilli etc. but some things do still get past. Salt is a preservative in food simply makes it an unhealthy environment for growth of bugs which are unhealthy for us. This is universal unless we encourage the conditions that suit botulism - an anerobic bug of some potency, very easy to avoid as oxygen (air exposure) kills it.
But don't listen to me, research and learn about it maybe.
