Optibac Probiotics One Week Flat is a short term, 7 day course of natural bacteria. Each sachet contains 5 billion live cultures of high quality strains including: - __Lactobacillus acidophilus Rosell-52:__ Acidophilus is a natural resident of the intestinal microflora; this strain of acidophilus from OptiBac has been shown to survive gastric acidity and biliary salts, and to reach the intestines without damage. - __Bifidobacterium bifidum Rosell-71:__ This well-researched strain has been shown to reach the gut alive. - __Lactobacillus casei Rosell-215:__ This is of an extensively studied species naturally residing in the intestinal flora; this strain from OptiBac has been researched in its ability to resist gastric acidity and bile salts in order to reach your small and large intestines alive. - __Lactococcus lactis Rosell-1058:__ This strain is extracted from the kefir culture, and has been scientifically proven to reach the gut alive. - __Fructooligosaccharide fibres (FOS):__ These provide a source of natural fibre. Gluten free – may be suitable for bloating sufferers. Suitable for vegetarians.