Two phenotypes exist in the human population with regard to expression of lactase in adults. Lactase non-persistence (adult-type hypolactasia and lactose intolerance) is characterized by a decline in the expression of lactase-phlorizin hydrolase (LPH) after weaning. In contrast, lactase-persistent individuals have a high LPH throughout their lifespan. Lactase persistence and non-persistence are...

Background/Overview Genetic testing of adults with suspected lactase insufficiency is proposed as an alternative to current diagnostic practices. Studies have demonstrated a tight correlation between a single nucleotide polymorphism (SNP) -13910 C > T upstream of the gene coding for the enzyme lactase and lactase insufficiency in persons of European ancestry. Currently, two indirect tests of la...

In the adult rat, starvation during 48 hours led to a three fold increase of lactase specific activity in the intestinal brush border membranes. Thyroxine injection during the three days before death (0.5 micrograms/g daily) inhibited the stimulation of lactase activity induced by starvation without modifying sucrase activity whereas hydrocortisone injections (25 micrograms/g daily) or thyroide...

BACKGROUND Postnatal development of rat intestine is associated with a decline in brush-border lactase activity. This phenomenon is similar to the adulthood hypolactasia in humans. However, the mechanism underlying this process is not understood. METHODS The effect of luminal proteases from adult rat intestine on the intestinal lactase activity in animals aged 7, 14, 21 and 30 days was studie...

Lactase non-persistence (leading to primary lactose intolerance) is a genetically dependent inability to digest lactose in adulthood. As part of the human adaptation to dairying, the human lactase LCT-13910C/T mutation (which propagates adult expression of lactase) developed, spread and participated in the adaptation to dairying. This variant is associated with lactase activity persistence, and...

Though humans are known to lose lactase ability post-weaning, some people maintain lactase production into adulthood, a condition known as lactase persistence. Global distribution patterns of lactase persistency are inconsistent; the condition is much more prevalent in some populations than others. Using results across independent studies, the existence of such a phenomenon can be attributed to...

Lactase has excellent applications in dairy industry and commercially this enzyme is produced from bacterial sources but not in high yields. In this work, the production of lactase was improved by designing of nutrient components in fermentation medium by one factor at a time. Lactose and yeast extract were selected as preferable carbon and nitrogen sources for lactase production with tryptopha...

© 2014 John Wiley & Sons, Ltd. Published 2014 by John Wiley & Sons, Ltd. The consumption of milk and dairy products varies considerably in different regions of the world. Indeed, according to the statistics of the Food and Agriculture Organization of the United Nations (FAO), in 2007 the consumption of milk and dairy products averaged 240 kg and 360 kg per capita in the UK and Sweden, respectiv...

Lactose malabsorption is a very common condition characterized by intestinal lactase deficiency. Primary lactose malabsorption is an inherited deficit present in the majority of the world's population, while secondary bypolactasia can be the consequence of an intestinal disease. The presence of malabsorbed lactose in the colonic lumen may cause gastrointestinal symptoms. This condition is known...

The prevalence of lactase deficiency in British adults is unknown. Examination of the distribution of lactase activities in single and multiple biopsies of jejunum indicated that 0.8 U/g wet weight was a suitable cut-off point to separate lactase deficient patients from others. One hundred and fifty white British adults were selected, none of whom had significant intestinal disease and all of w...