Cultures of "B. subtilis" were popular worldwide, before the introduction of antibiotics, as an immunostimulatory agent to aid treatment of gastrointestinal and urinary tract diseases. It was used throughout the 1950s as an alternative medicine, which upon digestion has been found to significantly stimulate broad-spectrum immune activity including activation of secretion of specific antibodies IgM, IgG and IgA and release of CpG dinucleotides inducing interferon IFN-α/IFNγ producing activity of leukocytes and cytokines important in the development of cytotoxicity towards tumor cells. It was marketed throughout America and Europe from 1946 as an immunostimulatory aid in the treatment of gut and urinary tract diseases such as Rotavirus and Shigellosis. It has been reported that in 1966 the U.S Army dumped "bacillus subtilis" onto the grates of New York City subway stations for four days in order to observe people's reactions when coated by a strange dust, due to its ability to survive it is thought to still be present there.