This is done by using glycosidase enzymes from specific bacteria to strip the blood group antigens from red blood cells. The removal of A and B antigens still does not address the problem of the Rh blood group antigen on the blood cells of Rh positive individuals, and so blood from Rh negative donors must be used. The sort of blood is named "enzyme converted to O" (ECO) blood. Patient trials will be conducted before the method can be relied on in live situations. One such Phase II trial was done on B-to-O blood in 2002.Another approach to the blood antigen problem is the manufacture of artificial blood, which could act as a substitute in emergencies. Pseudoscience
During the 1930s, connecting blood groups to personality types became popular in Japan and other areas of the world. Studies of this association have yet to confirm its existence definitively.Other popular but unsupported ideas include the use of a blood type diet, claims that group A causes severe hangovers, group O is associated with perfect teeth, and those with blood group A2 have the highest IQs. Scientific evidence in support of these concepts is limited at best. See also
Secretor status – secretion of ABO antigens in body fluids

References
Further reading
Dean L (2005). "Chapter 5: The ABO blood group". Blood Groups and Red Cell Antigens. Retrieved 24 March 2007. Farr A (1 April 1979). "Blood group serology--the first four decades (1900–1939)". Med Hist. 23 (2): 215–26. doi:10.1017/s0025727300051383. PMC 1082436. PMID 381816.
Several studies have observed that a relative down-regulation of GTA and GTB occurs in oral carcinomas in association with tumor development. More recently, a genome wide association study (GWAS) has identified variants in the ABO locus associated with susceptibility to pancreatic cancer. In addition, another large GWAS study has associated ABO-histo blood groups as well as FUT2 secretor status with the presence in the intestinal microbiome of specific bacterial species. In this case the association was with Bacteroides and Faecalibacterium spp. Bacteroides of the same OTU (operational taxonomic unit) have been shown to be associated with inflammatory bowel disease, thus the study suggests an important role for the ABO histo-blood group antigens as candidates for direct modulation of the human microbiome in health and disease. Clinical marker
A multi-locus genetic risk score study based on a combination of 27 loci, including the ABO gene, identified individuals at increased risk for both incident and recurrent coronary artery disease events, as well as an enhanced clinical benefit from statin therapy. The study was based on a community cohort study (the Malmo Diet and Cancer study) and four additional randomized controlled trials of primary prevention cohorts (JUPITER and ASCOT) and secondary prevention cohorts (CARE and PROVE IT-TIMI 22). Alteration of ABO antigens for transfusion
In April 2007, an international team of researchers announced in the journal Nature Biotechnology an inexpensive and efficient way to convert types A, B, and AB blood into type O.