Breastfeeding is the feeding of an infant or young child with breast milk directly from female human breasts (i.e., via lactation) rather than from a baby bottle or other container. Babies have a sucking reflex that enables them to suck and swallow milk. Most mothers can breastfeed for six months or more, without the addition of infant formula or solid food. Human breast milk is the healthiest form of milk for human babies.There are few exceptions, such as when the mother is taking certain drugs or is infected with human T-lymphotropic virus, HIV, or has active untreated tuberculosis. Breastfeeding promotes health, helps to prevent disease, and reduces health care and feeding costs. Artificial feeding is associated with more deaths from diarrhea in infants in both developing and developed countries. Experts agree that breastfeeding is beneficial, but may disagree about the length of breastfeeding that is most beneficial, and about the risks of using artificial formulas. The World Health Organization (WHO) and the American Academy of Pediatrics (AAP) emphasize the value of breastfeeding for mothers as well as children. Both recommend exclusive breastfeeding for the first six months of life and then supplemented breastfeeding for at least one year and up to two years or more. While recognizing the superiority of breastfeeding, regulating authorities also work to minimize the risks of artificial feeding. Recent British research suggested that though breastfeeding was still recommended for 4 months, solid food should be introduced after that to reduce the incidence of iron deficiency, allergies to peanuts and early onset coeliac disease. However, the British Department of Health stated, "Breast milk provides all the nutrients a baby needs up to six months of age and we recommend exclusive breastfeeding for this time." The WHO recommendation for exclusive breastfeeding for 6 months is important in developing countries where there is a higher incidence of gastroenteritis. This research has been criticized as biased as the paper states three of the four authors "have performed consultancy work and/or received research funding from companies manufacturing infant formulas and baby foods within the past three years".