Lactobacillus Casei
This species is commonly found in probiotic dairy foods such as 'live yoghurt', hence the name 'casei' which relates to the milk protein casein. It was reported in Microbiology and Immunology to have the most potent protective activity against the Listeria bacteria. Listeria is potentially lethal with about 30% of victims dying. It is most commonly transmitted through consumption of dairy products and raw vegetables. Like L.salivarius, L.casei, in the form of the shirota strain found in Yakult probiotic yoghurt drinks, has been shown to significantly inhibit the growth of the peptic ulcer causing bacteria H.pylori (12). A probiotic drink containing the shirota strain has also been shown to reduce the severity of constipation as evidenced by both patient response to questionnaires and physical examinations (13). Finally, a study with malnourished mice showed that L.casei (combined with FOS), when given along with a re-nutrition diet, enhanced the immune response and increased resistance to certain pathogenic bacteria in the digestive tract (14).