A bottle of Yakult, a<unk>  drink containing Lactobacillus paracasei<unk> s are live microorganisms promoted with claims that they provide health benefits when consumed, generally by improving or restoring the gut flora.<unk> s are considered generally safe to consume, but may cause bacteria-host interactions and unwanted side effects in rare cases. There is some evidence that<unk> s are beneficial for some conditions, but there is little evidence for many of the health benefits claimed for them. The first discovered<unk>  was a certain strain of bacillus in Bulgarian yogurt, called Lactobacillus bulgaricus. The discovery was made in 1905 by Bulgarian physician and microbiologist Stamen Grigorov. The modern-day theory is generally attributed to Russian Nobel laureate Élie Metchnikoff, who postulated around 1907 that yoghurt-consuming Bulgarian peasants lived longer. A growing<unk> s market has led to the need for stricter requirements for scientific substantiation of putative benefits conferred by microorganisms claimed to be<unk> . Although numerous claimed benefits are marketed towards using consumer<unk>  products, such as reducing gastrointestinal discomfort, improving immune health, relieving constipation, or avoiding the common cold, such claims are not supported by scientific evidence, and are prohibited as deceptive advertising in the United States by the Federal Trade Commission. As of 2019, numerous applications for approval of health claims by European manufacturers of<unk>  dietary supplements have been rejected by the European Food Safety Authority for insufficient evidence of beneficial mechanism or efficacy.
Probiotic
Postbiotic
Prebiotic 
Anthelmintic
Cathartic
Antiparasitic
Toxoid
Antiseptic