Noma is a polymicrobial, opportunistic infection which largely disappeared from the developed countries prior to discovery of antibiotics, but is still prevalent in poor sub-Saharan African communities, particularly in infants less than 4 years of age. These infants are severely stunted, reflecting in part a continuation of intra-uterine growth retardation (IUGR) which is common in such communities. Maternal malnutrition and poor health status adversely compromise the components of immune system which mature early in fetal life, and the resulting abnormalities are long-lasting into adolescence and adulthood. Impaired immune function associated with IUGR is further intensified by chronic postnatal malnutrition and endemic infections characteristic of deprived communities. Thus, an individual whose growth is compromised by a major intra uterine environmental factor (e.g. malnutrition) that alters expression of the fetal genome, has heightened vulnerability to the microorganisms that promote the development of noma. This speculation which requires experimental confirmation, may explain why noma occurs in children with severe combined immunodeficiency (SCID) diseases, in preterm babies (in form of noma neonatorum), in very poor immunocompromised, malnourished children and adolescents, and in some victims of HIV infection/AIDS, diabetes mellitus and other immunosuppressive conditions.