Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, Bifidobacterium infantis, these are some of the most healthy and used probiotic bacteria strains in probiotic supplements and you should look for them in your supplements as well, or in products that contain probiotic bacteria.
Bifidobacterium bifidum is one of the most popular prbiotic strains in the Bifidobacterium species and it can be found in the mucus of the large intestine as well as the vaginal tract, much like other strains of bacteria.
Most probiotic bacteria are in fact found in the intestines and also the colon, but some of them also live in the vagina, the urethra, the saliva, etc.
Bifidobacterium bifidum can produce lactic acid as well as acetic acid, changing pH levels in the human body and making them favorable for the reproduction and colonization of probiotic strains like itself.
This strain and multiple others aid in the prevention of gastrointestinal problems and promote a healthier body and longevity. The best thing about probiotics, as you will hear from multiple sources, is that they inhabit your body and create a symbiotic relation with it and by consuming them regularly they help you in the fight against pathogens, decreasing the risk of bacterial infections and what better way to stay healthy than to avoid health problems?
Avoiding them is much better than treating them using antibiotics and let me take this opportunity to talk very shortly about antibiotics. Antibiotic use helps in treating infections by killing pathogens, but they will also eliminate probiotics. This causes long term risk of infection because antibiotics keep pathogens away, their absence makes you vulnerable. One more thing, antibiotics produce antibiotic resistance in pathogens, another bad thing because it makes the problems they cause, more difficult to treat.
A medic would advise against using an antibiotic or abusing them unless there really is a need to and there is no other, better solution. Many abuse them but because of this, the side-effects are quite harmful and outweigh the benefits that they bring. Since probiotics can be naturally found in foods, it is easy for everyone to use them and protect themselves from such problems as to avoid others.