The Optibac Probiotics 5 Billion Bifidobacteria & Fibre sachets have been formulated to help relieve symptoms of constipation and IBS. The 5 Billion Bifidobacteria is a high-quality strain that has been proven to survive stomach acidity so that it reaches the gut alive. These sachets are free from Gluten, Yeats, Soya and artificial flavours.