[Lactose intolerance: past and present. Part 1]. / A laktózintoleranciáról: Múlt és jelen - I. rész.

Lactose intolerance is the most prevalent intestinal malabsorption disorder. After presentation of its history, the author describes the emergence of lactose intolerance during the evolution of species, and the biochemistry of lactose as well as features of human and bacterial lactase enzymes are then described. The unequal distribution of lactose intolerance in different continents and population is discussed, followed by presentation of past and present prevalence data in Hungary. Adult-type hypolactasia is caused by a polymorphism of the MCM6 gene located upstream from the lactase gene on the long arm of the chromosome 2. It can be determined with the polymerase chain reaction. The intestinal symptoms of lactose intolerance are well known, but its extra-intestinal manifestations are less recognised. Invasive diagnostic methods (determination of lactase activity from small intestinal biopsies, lactose tolerance test), are accurate, but have been replaced by the non-invasive methods; their gold standard is the H2 breath test. Genetic testing is being used more and more frequently in Hungary too, and, presumably, the methane breath test will be also available in the near future. Lactose intolerance can be accompanied by inflammatory bowel diseases, coeliac disease and irritable bowel syndrome; it could be established whether this association is causal or not in order to start a correct diet and therapy.

Intolerancia a la lactosa / Lactose intolerance

La intolerancia a la lactosa (IL) es el síndrome de malabsorción más frecuente en la infancia y adolescencia. Se manifiesta con dolor, molestias abdominales, diarrea, flatulencia, distensión abdominal, náuseas e incluso vómitos. La lactosa es un disacárido presente en la leche que se hidroliza gracias a la acción de la lactasa-floricina-hidrolasa (LPH). Así, la IL se produce cuando, por diferentes circunstancias (transitorias como las infecciones o genéticas), la LPH disminuye/pierde su función induciendo una carencia en la digestión de la lactosa. Puesto que en esta situación se produce (en muchos casos) una retirada de lácteos, debe controlarse especialmente la ingestión de calcio y, por la particular dependencia de este, la densidad mineral ósea (DMO). La DMO es un factor relevante para prevenir la osteoporosis y, dado que una buena masa ósea en la etapa adulta dependerá del acopio efectuado durante la infancia, se debe prestar especial atención a los aspectos nutricionales. Para ello, existen diferentes opciones dietéticas como leche sin lactosa o de baja concentración además de bebidas vegetales o alimentos ricos en calcio; sin embargo, estas dos últimas opciones son inadecuadas nutricionalmente como sustitutivas de la leche (AU)

Lactose intolerance (LI) is the most common malabsorption syndrome in childhood and adolescence. It manifests itself as pain, abdominal trouble, diarrhoea, flatulence, abdominal distension, nausea and even vomiting. Lactose is a disaccharide present in milk which is hydrolysed through the action of lactase-phlorizin hydrolase (LPH). Thus, LI occurs when, for different reasons (transitory infections or genetic), the LPH diminishes/loses its function, inducing a deficiency in lactose digestion. As in this situation dairy products are often withdrawn, special care must be taken to monitor calcium intake and, due to its particular dependence on this, bone mineral density (BMD). BMD is an important factor in preventing osteoporosis and, as good bone mass in adulthood will depend on that built up in childhood, special attention must be paid to nutritional aspects. There are different dietary options for this purpose, such as lactose-free milk or milk with a low lactose content, as well as plant-based drinks or calcium-rich foods; however, the latter two options are nutritionally inadequate as milk substitutes (AU)

Short- and long-term effects of a lactose-restricted diet and probiotics in children with chronic abdominal pain: a retrospective study.

OBJECTIVE: To determine the short- and long-term effect of treatment in children with chronic abdominal pain (CAP). METHODS: A database with the results of H(2) breath test of children with CAP was created. All children with an abnormal test result were included and classified as small intestinal bacterial overgrowth (SIBO) or lactose intolerant (LTI). SIBO was treated with probiotics and LTI with a lactose-restricted diet. CAP was evaluated 5 months and 15 months after the test. RESULTS: 37 children (41%) were included. 17 LTI children (94%) improved after 5 months and 11 children (61%) after 15 months (P<0.05). Seven SIBO children improved after 5 months and 4 children after 15 months. In the combination group all 4 children improved after 5 months and 3 children after 15 months. CONCLUSION: Children with CAP caused by LTI or SIBO had less CAP after 5 months. This positive effect persists only in half of the children.

Effects of yogurt and bifidobacteria supplementation on the colonic microbiota in lactose-intolerant subjects.

AIMS: Colonic metabolism of lactose may play a role in lactose intolerance. We investigated whether a 2-week supplementation of Bifidobacterium longum (in capsules) and a yogurt enriched with Bifidobacterium animalis could modify the composition and metabolic activities of the colonic microbiota in 11 Chinese lactose-intolerant subjects. METHODS AND RESULTS: The numbers of total cells, total bacteria and the Eubacterium rectale/Clostridium coccoides group in faeces as measured with fluorescent in situ hybridization and the faecal beta-galactosidase activity increased significantly during supplementation. The number of Bifidobacterium showed a tendency to increase during and after supplementation. With PCR-denaturing gradient gel electrophoresis, in subjects in which B. animalis and B. longum were not detected before supplementation, both strains were present in faeces during supplementation, but disappeared after supplementation. The degree of lactose digestion in the small intestine and the oro-caecal transit time were not different before and after supplementation, whereas symptom scores after lactose challenge decreased after supplementation. CONCLUSIONS: The results suggest that supplementation modifies the amount and metabolic activities of the colonic microbiota and alleviates symptoms in lactose-intolerant subjects. The changes in the colonic microbiota might be among the factors modified by the supplementation which lead to the alleviation of lactose intolerance. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides evidence for the possibility of managing lactose intolerance with dietary lactose (yogurt) and probiotics via modulating the colonic microbiota.

Gastrointestinal dysfunction in a community sample of subjects with symptoms of irritable bowel syndrome.

BACKGROUND/AIM: Irritable bowel syndrome (IBS) affects about 15-20% of the population of the Western countries. Traditionally, IBS has been an exclusion diagnosis, but recently definitions have emerged from population-based research. The aim of this population-based study was to evaluate any association between gastrointestinal pathophysiology and IBS in subjects with symptoms of IBS compared to subjects with no abdominal complaints. METHODS: From a random sample of 2,656 participants, subjects with IBS (32) together with subjects without abdominal complaints (26), were invited for further evaluation. IBS was defined as more than weekly experience of abdominal pain and distension, and in addition either borborygmia or altering stool consistency. The diagnostic work-up consisted of gastroscopy, manometry and 23-hour pH and pressure recordings of the oesophagus, lactose tolerance test, barium enema, measurement of colonic transit time, and rectoscopy. RESULTS: Compared to the group without abdominal complaints significantly more subjects with IBS had spasms of the colon (OR = 10.2 (1.2-87.3)), and abnormal contractions of the oesophagus at manometry (OR = 9.1 (1.1-78.2)). Furthermore, there was a non-significant tendency towards spasms at 23-hour pH and pressure recordings (OR = 3.58 (0.4-35.2)), and more discomfort at lactose tolerance test (OR = 5.8 (0.6-51.3)) in persons with IBS compared to subjects without abdominal complaints. CONCLUSION: The results of this population-based study indicate that signs of gastrointestinal dysmotility and hyperperception are more prevalent in subjects with IBS than in subjects without abdominal complaints.

Aceitação e tolerância de leite de cabra em pré-escolares / Acceptability and tolerance of goat milk in preschool children

Os autores procederam a um estudo sobre a aceitaçäo e tolerância do leite de cabra em pré-escolares de três creches municipais da cidade de Säo Paulo, concluindo tratar-se de excelente opçäo para substituiçäo do leite de vaca, após o primeiro ano de vida. Foram analisados o leite de cabra em pó e na forma UHT, enriquecido com ferro e vitaminas, visando o controle da anemia, muito frequente nessas crianças. Näo houve registro de alergia ou intolerância no decorrer do estudo e, em crianças normais, o uso do leite de cabra favoreceu a ingestäo láctea e, por isso, de cálcio

Gut transit time and lactose malabsorption during phototherapy. I. A study using lactose-free human mature milk.

Sixty newborn infants with normal birth weight suffering from uncomplicated hyperbilirubinemia were studied. They were fed human mature milk from which lactose had been eliminated, whereafter either sucrose ("sucrose milk") or lactose ("lactose milk") was added. 30 infants received ordinary phototherapy and 30 intensive phototherapy (blue double light). 15 in each group had "sucrose milk" and 15 "lactose milk". There was no significant difference between the increase in blood glucose (delta BS) by lactose tolerance tests performed before phototherapy (LTT1) and by those performed during phototherapy (LTT11), neither in infants treated with ordinary nor with intensive phototherapy. All infants had normal delta BS-LTT11, except one receiving ordinary phototherapy. There was no significant difference in gut transit time between infants having "sucrose milk" and infants having "lactose milk", neither in those treated with ordinary nor with intensive phototherapy. Gut transit time was significantly shorter in infants treated with intensive phototherapy than in infants treated with ordinary phototherapy without there being any significant difference in delta BS-LTT11. The infant with flat LTT11 may have developed lactose malabsorption during the phototherapy. Thus, lactose malabsorption is not the usual cause of the reduced gut transit time during phototherapy and must be a rare complication in phototherapy.

Gut transit time and lactose malabsorption during phototherapy. II. A study using raw milk from the mothers of the infants.

Thirty newborn infants with normal birth weight suffering from uncomplicated hyperbilirubinemia were studied. 15 infants received ordinary phototherapy and 15 intensive phototherapy (blue double light). All infants received their mothers' milk or fresh milk from mothers of other newborn infants of the same age. All infants had normal lactose tolerance test during the phototherapy, except one infant receiving ordinary transit time was relatively long. The gut transit time was significantly shorter in the infants treated with intensive phototherapy than in those treated with ordinary phototherapy without there being any significant difference in the increase in blood glucose by lactose tolerance tests. It is concluded that lactose malabsorption is not the usual cause of the reduced gut transit time during phototherapy even if the infants receive their mothers' milk.

Disaccharide consumption and malabsorption in Canadian Indians.

Twenty-eight Sioux and 29 Saluteaux Indians from a southern and an isolated northern Manitoban community were screened for lactose malabsorption; 55 were also screened for sucrose tolerance. Sixty percent of the subjects were lactose malabsorbers; the incidence increased with age. Lactase deficiency appeared, on the average, between 8 and 15 years of age. About 45% of the subjects were lactose intolerant. Malabsorbers who did not regularly drink milk had the highest symptom scores. The northern subjects consumed significantly more lactose and sucrose than the southern subjects. Two Sioux children were sucrose malabsorbers. It was hypothesized that the significantly greater sucrose consumption by the Saulteaux subjects were responsible for their markedly higher blood glucose curve following the sucrose tolerance tests. Dietary sucrose increases jejunal sucrase activity and the intestinal transport of glucose and fructose. Three of eight children less than 4 years were lactose malabsorbers; hence, medical personnel treating noninjective diarrhea in Indian children should examine for lactase deficiency. It was recommended that vitamin D fortified milk supplements to Indian school children be continued and that the milk be treated so as to reduce abdominal symptoms in the intolerant individuals.

The application of the "Lojda" method for intestinal lactase in intestinal biopsies from jaundiced newborn infants.

A new use of the histochemical method for intestinal lactase activity is described. Peroral intestinal biopsies from newborn light-treated infants with diarrhoea were investigated for brush-border lactase. The lactase activity found in these infants by the histochemical method correlated well with the infants ability to hydrolyze lactose judged by lactose tolerance test.

Temproary intestinal lactase deficiency in light-treated jaundiced infants.

The intestinal lactase activity in six newborn jaundiced light-treated infants with diarrhea and in eight normal controls were compared by lactose tolerance test (LTT). The ability to hydrolyze lactose was minimal in the jaundiced infants during light-treatment compared to the controls which could absorb lactose very well. Peroral intestinal biopsies were taken from the newborn jaundiced infants during light-treatment. By histochemical technique no intestinal lactase activity was found in these intestines. When the jaundiced infants with diarrhea were given lactose-free diet, the stools normalized. The effect was reversed when breast milk was given while the baby was still jaundiced and light-treated. These findings indicate that the increased amounts of unconjugated bilirubin in the intestine of jaundiced infants during light-treatment inhibit the intestinal brush-border lactase. When the icterus fades the lactase is again active. The practical consequence is to give light-treated infants lactose-free diet if they get diarrhea, and to reintroduce breast milk or other lactose containing diet when the baby is no longer icteric.