The Austrian firm will gain exclusive rights to market the BioGaia dental products, tablets and baby drops in pharmacies and clinics in Austria.
HSO expects to launch the products in the middle of 2006.
"This agreement is important, as it is the first international agreement for the BioGaia branded dental products and also the first partner who will launch a complete portfolio of BioGaia products," said the firm.
BioGaia has diversified into a number of new applications, moving away from the most established probiotic delivery form of tablets and dairy products.
Its probiotic bacteria drops have been tested for their effects on the symptoms of colic in breast-feeding infants with positive results.The dental products, containing a bacteria that is said to counter the effects of bad bacteria in the mouth, come in the form of lozenges and chewing gum.
HSO Pharma already markets capsules for gut health and vaginal health and said the product extension would make it a complete probiotic supplier.