Assessment of lactase activity in humans by measurement of galactitol and galactonate in serum and urine after milk intake

ABSTRACT Background Lactase is an enzyme that hydrolyzes lactose into glucose and galactose in the small intestine, where they are absorbed. Hypolactasia is a common condition, primarily caused by genetic programming, that leads to lactose maldigestion and, in certain cases, lactose intolerance. Galactitol and galactonate are 2 products of hepatic galactose metabolism that are candidate markers for the intake of lactose-containing foods. Objectives The primary objective of the study was to explore the changes in serum and urine metabolomes during postprandial dairy product tests through the association between lactase persistence genotype and the postprandial dynamics of lactose-derived metabolites. Methods We characterized the 6-h postprandial serum kinetics and urinary excretion of lactose, galactose, galactitol, and galactonate in 14 healthy men who had consumed a single dose of acidified milk (800 g) which contained 38.8 g lactose. Genotyping of LCT-13910 C/T (rs4988235) was performed to assess primary lactase persistence. Results There were 2 distinct postprandial responses, classified as high and low metabolite responses, observed for galactose, and its metabolites galactitol and galactonate, in serum and urine. In all but 1 subject, there was a concordance between the high metabolite responses and genetic lactase persistence and between the low metabolite responses and genetic lactase nonpersistence (accuracy 0.92), galactitol and galactonate being more discriminative than galactose. Conclusions Postprandial galactitol and galactonate after lactose overload appear to be good proxies for genetically determined lactase activity. The development of a noninvasive lactose digestion test based on the measurement of these metabolites in urine could be clinically useful. This trial was registered at clinicaltrials.gov as NCT02230345.

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Adult Lactose Digestion Status and Effects on Disease

Canadian Journal of Gastroenterology and Hepatology ◽

10.1155/2015/904686 ◽

2015 ◽

Vol 29 (3) ◽

pp. 149-156 ◽

Cited By ~ 9

Author(s):

Andrew Szilagyi

Keyword(s):

Lactose Intolerance ◽

Lactase Persistence ◽

Dairy Foods ◽

Microbial Adaptation ◽

Lactose Maldigestion ◽

Before And After ◽

Disease Pattern ◽

Definition Of ◽

Detrimental Impact ◽

Manual Review

BACKGROUND: Adult assimilation of lactose divides humans into dominant lactase-persistent and recessive nonpersistent phenotypes.OBJECTIVES: To review three medical parameters of lactose digestion, namely: the changing concept of lactose intolerance; the possible impact on diseases of microbial adaptation in lactase-nonpersistent populations; and the possibility that the evolution of lactase has influenced some disease pattern distributions.METHODS: A PubMed, Google Scholar and manual review of articles were used to provide a narrative review of the topic.RESULTS: The concept of lactose intolerance is changing and merging with food intolerances. Microbial adaptation to regular lactose consumption in lactase-nonpersistent individuals is supported by limited evidence. There is evidence suggestive of a relationship among geographical distributions of latitude, sunhine exposure and lactase proportional distributions worldwide.DISCUSSION: The definition of lactose intolerance has shifted away from association with lactose maldigestion. Lactose sensitivity is described equally in lactose digesters and maldigesters. The important medical consequence of withholding dairy foods could have a detrimental impact on several diseases; in addition, microbial adaptation in lactase-nonpersistent populations may alter risk for some diseases. There is suggestive evidence that the emergence of lactase persistence, together with human migrations before and after the emergence of lactase persistence, have impacted modern-day diseases.CONCLUSIONS: Lactose maldigestion and lactose intolerance are not synonymous. Withholding dairy foods is a poor method to treat lactose intolerance. Further epidemiological work could shed light on the possible effects of microbial adaptation in lactose maldigesters. The evolutionary impact of lactase may be still ongoing.

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Lactose Intolerance, Dairy Avoidance, and Treatment Options

Nutrients ◽

10.3390/nu10121994 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1994 ◽

Cited By ~ 27

Author(s):

Andrew Szilagyi ◽

Norma Ishayek

Keyword(s):

Lactose Intolerance ◽

Treatment Options ◽

Functional Gastrointestinal Disorders ◽

Gastrointestinal Symptoms ◽

Common Source ◽

Chromosome 2 ◽

Dietary Interventions ◽

Dairy Foods ◽

Lactose Maldigestion ◽

Genetically Determined

Lactose intolerance refers to symptoms related to the consumption of lactose-containing dairy foods, which are the most common source for this disaccharide. While four causes are described, the most common is the genetically-determined adult onset lactose maldigestion due to loss of intestinal lactase governed by control of the gene by a 14,000 kb promoter region on chromosome 2. Gastrointestinal symptoms from lactose have expanded to include systemic effects and have also been confounded by other food intolerances or functional gastrointestinal disorders. Partly because lactose maldigestion is often interpreted as lactose intolerance (symptoms), focus of therapy for these symptoms starts with lactose restriction. However, withholding of dairy foods completely is not appropriate due to a more favorable impact on health. Industrial efforts to substitute with plant-based products is not completely successful at this time. This narrative article reviews the complexities of the perception of lactose intolerance, its epidemiology, and pathogenesis. Treatments are discussed, including the inappropriateness of dairy avoidance. In conjunction, effects of dairy products on 19 common diseases are reviewed. Different methods of treatment, lactose-reduced products, plant-based dairy substitutes, adaptation, prebiotics, exogenous lactase, probiotics, and some other dietary interventions are further discussed.

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Relationship between Lactase Activity and Intestinal Flora Structure

Tobacco Regulatory Science ◽

10.18001/trs.7.5.1.81 ◽

2021 ◽

Vol 7 (5) ◽

pp. 3104-3109

Author(s):

Ying Zhang ◽

Mingjian Huang ◽

Jianfeng Chen ◽

Shuyuan Wang ◽

Jian Xu

Keyword(s):

Young Children ◽

Intestinal Tract ◽

Lactose Intolerance ◽

Intestinal Flora ◽

Control Group ◽

Lactase Activity ◽

Beneficial Bacteria ◽

The Relationship ◽

Experimental Group ◽

Infants And Young Children

To analyze and explore the relationship between lactase activity and the structure of intestinal flora in infants under 1 year old. Method: Our hospital selected 60 infants and young children in the Haizhu Maternity and Child Health Hospital from August 2019 to September 2020 as the research objects. The infants in the experimental group were diagnosed as lactose intolerant infants, the control group were normal infants, and the experimental group and control group had 30 cases each. The relationship between lactase activity and intestinal flora structure. Result: The experimental group had fewer beneficial bacteria in the intestinal tract than the control group, but improved lactase activity by correcting the structure of the intestinal flora and alleviating symptoms of lactose intolerance. Conclusion: Infants and young children are prone to non-infectious diarrhea, and the causes are more complicated, but most of them are related to lactose intolerance. When infants and young children develop lactose intolerance, it is necessary to pay attention to the lack of beneficial bacteria in the intestinal tract. Targeted supplementation of probiotics (such as Lactobacillus reuteri, Clostridium butyricum, etc.) can correct the intestinal flora, improve lactase activity, and relieve symptoms of lactose intolerance.

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Population Genetics of Lactase Persistence and Lactose Intolerance

Encyclopedia of Life Sciences ◽

10.1002/9780470015902.a0020855 ◽

2007 ◽

Author(s):

Catherine Janet Ellen Ingram ◽

Dallas Mary Swallow

Keyword(s):

Population Genetics ◽

Lactose Intolerance ◽

Lactase Persistence

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Population Genetics of Lactase Persistence and Lactose Intolerance

Encyclopedia of Life Sciences ◽

10.1002/9780470015902.a0020855.pub2 ◽

2012 ◽

Cited By ~ 3

Author(s):

Catherine JE Ingram ◽

Anke Liebert ◽

Dallas M Swallow

Keyword(s):

Population Genetics ◽

Lactose Intolerance ◽

Lactase Persistence

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Carbohydrate intolerance

10.1093/med/9780198759928.003.0020 ◽

2018 ◽

Author(s):

John Puntis

Keyword(s):

Enzyme Assay ◽

Watery Diarrhoea ◽

Dietary Modification ◽

Breath Hydrogen ◽

Common Cause ◽

Enzyme Replacement ◽

Gene Testing ◽

Lactose Maldigestion ◽

Genetically Determined ◽

Carbohydrate Intolerance

Symptoms such as watery diarrhoea, wind, and abdominal cramps should raise the possibility of carbohydrate intolerance. Lactose maldigestion is the most common cause and can be transient, after gastroenteritis, or in some populations is genetically determined with increasing age. Congenital sucrase–isomaltase deficiency (CSID) is underdiagnosed but amenable to treatment with dietary modification and oral enzyme replacement. Glucose–galactose malabsorption presents with watery diarrhoea from the time of first feeds. Investigations include sugar chromatography (when available), breath hydrogen testing, mucosal enzyme assay, and gene testing for CSID.

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Evaluation of Lactose in Milk and Dairy Products

International Journal for Innovation Education and Research ◽

10.31686/ijier.vol1.iss3.115 ◽

2013 ◽

Vol 1 (3) ◽

pp. 56-59

Author(s):

Simone Leal da Costa ◽

Natália Porfírio Rossi ◽

Rafael Resende Maldonado

Keyword(s):

Abdominal Pain ◽

Human Body ◽

Dairy Products ◽

Lactose Intolerance ◽

Galactose Metabolism ◽

Condensed Milk ◽

Lactose Concentration ◽

Milk And Dairy Products

Milk is an emulsion containing fat, protein, carbohydrate, vitamins, minerals and water. Lactose is the main carbohydrate presented in milk and dairy products. This sugar is composed by one unit of glucose and one of galactose. Metabolism of lactose depends on enzyme lactase which hydrolyzes this sugar. In some cases, lactase may be absent or an insufficient quantity in human body. Deficiency in lactase production causes numerous symptoms such as diarrhea; abdominal pain and bloating that characterize lactose intolerance. The aim of this work was to evaluate concentration of lactose in milk and dairy products to determine the effect of the processing and to calculate the quantity of each product which can be consumed without symptoms in lactose intolerant. Results obtained show lactose concentration of 4.42% w/v in Milk; 3.5% w/w in Minas cheese; 9.9%w/v in condensed milk and 4.76%w/v in yogurt. Portion innocous ranged from 60 to 170 mL depending on each product.

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Evaluation of a Digital Handheld Hydrogen Breath Monitor to Diagnose Lactose Malabsorption: Interventional Crossover Study (Preprint)

10.2196/preprints.33009 ◽

2021 ◽

Author(s):

Simon C Mathews ◽

Sandy Templeton ◽

Stephanie K Taylor ◽

Sten Harris ◽

Margaret Stewart ◽

...

Keyword(s):

Crossover Study ◽

Diagnostic Performance ◽

Lactose Intolerance ◽

Gastrointestinal Symptoms ◽

Common Condition ◽

Lactose Malabsorption ◽

Percent Agreement ◽

Adult Participants ◽

History Of ◽

Symptom Recall

BACKGROUND Lactose malabsorption is a common condition that affects a broad segment of the population. Clinical diagnosis based on symptom recall can be unreliable and conventional testing can be inconvenient, requiring expensive laboratory-based equipment and conduction of the testing in a clinical setting. OBJECTIVE The aim of this study is to assess the performance of a digital handheld hydrogen breath monitor (GIMate) in diagnosing lactose malabsorption compared to a US Food and Drug Administration (FDA)–cleared device (H2 Check) for the same indication. METHODS An interventional crossover study was performed in adult participants with a prior confirmed diagnosis of lactose malabsorption or a suspected history of lactose intolerance. RESULTS A total of 31 participants (mean age 33.9 years) were enrolled in the study. There was 100% positive percent agreement and 100% negative percent agreement between the GIMate monitor and the H2 Check. Correlation between gastrointestinal symptoms and hydrogen values was positive at 0.82 (<i>P</i><.001). CONCLUSIONS The digital handheld GIMate breath monitor achieved equivalent diagnostic performance to that of an FDA-cleared device in the diagnosis of lactose malabsorption. CLINICALTRIAL ClinicalTrials.gov NCT04754724; https://clinicaltrials.gov/ct2/show/NCT04754724

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Puberty and fertility in classic galactosemia

Endocrine Connections ◽

10.1530/ec-21-0013 ◽

2021 ◽

Author(s):

Isabelle Flechtner ◽

Magali Viaud ◽

Dulanjalee Kariyawasam ◽

Marie Perrissin-Fabert ◽

Maud Bidet ◽

...

Keyword(s):

Age Groups ◽

Dietary Treatment ◽

Oocyte Donation ◽

Primary Objective ◽

Breast Development ◽

Normal Range ◽

Galactose Metabolism ◽

Birth Prevalence ◽

Classic Galactosemia ◽

Pelvic Morphology

Classic galactosemia is a rare inborn error of galactose metabolism with a birth prevalence of about 1/30 000-60 000. Long-term complications occurring despite dietary treatment consist of premature ovarian insufficiency (POI) and neurodevelopmental impairments. We performed with the French Reference Centers for Rare Diseases a multisite collaborative questionnaire survey for classic galactosemic patients. Its primary objective was to assess their puberty, pregnancy, gonadotrop axis, and pelvic morphology by ultrasound The secondary objective was to determine predictive factors for potent pregnancy without oocyte donation. Completed questionnaires from 103 patients, 56 females (median age, 19 years [5-52 years]) and 47 males (median age, 19 years [3-45 years]), were analyzed. Among the 45 females older than 11 years old, mean age for breast development first stage was 12 years; spontaneous menarche occurred in 25 females at a mean age of 14.6 years. After puberty, 60% of females had irregular menstrual cycles and 50% experienced amenorrhea at a median age of 30 years [15;42]. All age-groups confounded, FSH was above normal range for 65% of the patients, anti-Müllerian hormone and inhibin B were below the normal range according to age, and the ovaries were small with few or no follicles detected. Among the 5 females who sought to conceive, 4 had pregnancies. Among the 47 males, 1 had cryptorchidism, all have normal testicular function and none had tried to conceive. Thus, spontaneous puberty and POI are both common in this population. Spontaneous menarche seems to be the best predictive factor for successful spontaneous pregnancy.

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