Breath Testing for Lactose Intolerance

Food intolerance can cause a range of gut and systemic symptoms [1]. The possibility that these conditions might be caused by intolerance to lactose has often been missed because it is not generally appreciated how widely lactose is used as a food additive: the addition of lactose to manufactured foods and drinks is not necessarily mentioned on the package label. Lactose has about one sixth of the sweetness of sucrose and, unlike sucrose or glucose, is not metabolized effectively by yeast. Thus lactose can be added to foods and drinks without causing a sickly sweet taste and without generating carbon dioxide or ethanol as a result of yeast metabolism [2]. Lactose is used as a browning agent in bread and cakes, is added to processed meats such as sausages and burgers, and is even injected into some chicken meat. It is also added to some soft drinks and lagers, breakfast drinks, and slimming products. As a result there is often confusion where dietary advice is confined to the avoidance of dairy foods.