Persistent high intestinal lactase activity in Papua New Guinea. The breath hydrogen test in a Sepik population

A sample of volunteers from the north-west of Papua New Guinea has been tested for persistent high intestinal lactase activity by measuring the breath hydrogen content before and after the administration of a preparation containing 50 g lactose. Eight of 35 persons were found to be absorbers of lactose. In common with other recent studies, this proportion establishes that the polymorphism occurs on the island, though the frequency of absorbers is nowhere high. The breath hydrogen method of estimating status has been shown to be capable of providing unequivocal, convincing results in the field.