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513 KiB

Open AccessArticle

Contribution of Colonic Fermentation and Fecal Water Toxicity to the Pathophysiology of Lactose-Intolerance

by Karen Windey, Els Houben, Lise Deroover and Kristin Verbeke

Nutrients 2015, 7(9), 7505-7522; https://0-doi-org.brum.beds.ac.uk/10.3390/nu7095349 - 08 Sep 2015

Cited by 14 | Viewed by 6857

Whether or not abdominal symptoms occur in subjects with small intestinal lactose malabsorption might depend on differences in colonic fermentation. To evaluate this hypothesis, we collected fecal samples from subjects with lactose malabsorption with abdominal complaints (LM-IT, n = 11) and without abdominal [...] Read more.

Whether or not abdominal symptoms occur in subjects with small intestinal lactose malabsorption might depend on differences in colonic fermentation. To evaluate this hypothesis, we collected fecal samples from subjects with lactose malabsorption with abdominal complaints (LM-IT, n = 11) and without abdominal complaints (LM-T, n = 8) and subjects with normal lactose digestion (NLD, n = 15). Lactose malabsorption was diagnosed using a ¹³C-lactose breath test. Colonic fermentation was characterized in fecal samples at baseline and after incubation with lactose for 3 h, 6 h and 24 h through a metabolomics approach using gas chromatography-mass spectrometry (GC-MS). Fecal water cytotoxicity was analyzed using a colorimetric assay. Fecal water cytotoxicity was not different between the three groups (Kruskall-Wallis p = 0.164). Cluster analysis of the metabolite patterns revealed separate clusters for NLD, LM-T and LM-IT samples at baseline and after 24 h incubation with lactose. Levels of 5-methyl-2-furancarboxaldehyde were significantly higher in LM-IT and LM-T compared to NLD whereas those of an unidentified aldehyde were significantly higher in LM-IT compared to LM-T and NLD. Incubation with lactose increased short chain fatty acid (SCFA) concentrations more in LM-IT and LM-T compared to NLD. In conclusion, fermentation patterns were clearly different in NLD, LM-IT and LM-T, but not related to differences in fecal water cytotoxicity. Full article

(This article belongs to the Special Issue Lactose Intolerance: Biology, Genetics and Dietary Management)

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658 KiB

Open AccessArticle

Additional Value of CH₄ Measurement in a Combined ¹³C/H₂ Lactose Malabsorption Breath Test: A Retrospective Analysis

by Els Houben, Vicky De Preter, Jaak Billen, Marc Van Ranst and Kristin Verbeke

Nutrients 2015, 7(9), 7469-7485; https://0-doi-org.brum.beds.ac.uk/10.3390/nu7095348 - 07 Sep 2015

Cited by 22 | Viewed by 6306

Abstract

The lactose hydrogen breath test is a commonly used, non-invasive method for the detection of lactose malabsorption and is based on an abnormal increase in breath hydrogen (H₂) excretion after an oral dose of lactose. We use a combined ¹³C/H [...] Read more.

The lactose hydrogen breath test is a commonly used, non-invasive method for the detection of lactose malabsorption and is based on an abnormal increase in breath hydrogen (H₂) excretion after an oral dose of lactose. We use a combined ¹³C/H₂ lactose breath test that measures breath ¹³CO₂ as a measure of lactose digestion in addition to H₂ and that has a better sensitivity and specificity than the standard test. The present retrospective study evaluated the results of 1051 ¹³C/H₂ lactose breath tests to assess the impact on the diagnostic accuracy of measuring breath CH₄ in addition to H₂ and ¹³CO₂. Based on the ¹³C/H₂ breath test, 314 patients were diagnosed with lactase deficiency, 138 with lactose malabsorption or small bowel bacterial overgrowth (SIBO), and 599 with normal lactose digestion. Additional measurement of CH₄ further improved the accuracy of the test as 16% subjects with normal lactose digestion and no H₂-excretion were found to excrete CH₄. These subjects should have been classified as subjects with lactose malabsorption or SIBO. In conclusion, measuring CH₄-concentrations has an added value to the ¹³C/H₂ breath test to identify methanogenic subjects with lactose malabsorption or SIBO. Full article

(This article belongs to the Special Issue Lactose Intolerance: Biology, Genetics and Dietary Management)

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Open AccessArticle

Adaptation to Lactose in Lactase Non Persistent People: Effects on Intolerance and the Relationship between Dairy Food Consumption and Evalution of Diseases

by Andrew Szilagyi

Nutrients 2015, 7(8), 6751-6779; https://0-doi-org.brum.beds.ac.uk/10.3390/nu7085309 - 13 Aug 2015

Cited by 57 | Viewed by 15858

Abstract

Dairy foods contain complex nutrients which interact with the host. Yet, evolution of lactase persistence has divided the human species into those that can or cannot digest lactose in adulthood. Such a ubiquitous trait has differential effects on humanity. The literature is reviewed [...] Read more.

Dairy foods contain complex nutrients which interact with the host. Yet, evolution of lactase persistence has divided the human species into those that can or cannot digest lactose in adulthood. Such a ubiquitous trait has differential effects on humanity. The literature is reviewed to explore how the divide affects lactose handling by lactase non persistent persons. There are two basic differences in digesters. Firstly, maldigesters consume less dairy foods, and secondly, excess lactose is digested by colonic microflora. Lactose intolerance in maldigesters may occur with random lactose ingestion. However, lactose intolerance without maldigestion tends to detract from gaining a clear understanding of the mechanisms of symptoms formation and leads to confusion with regards to dairy food consumption. The main consequence of intolerance is withholding dairy foods. However, regular dairy food consumption by lactase non persistent people could lead to colonic adaptation by the microbiome. This process may mimic a prebiotic effect and allows lactase non persistent people to consume more dairy foods enhancing a favorable microbiome. This process then could lead to alterations in outcome of diseases in response to dairy foods in lactose maldigesters. The evidence that lactose is a selective human prebiotic is reviewed and current links between dairy foods and some diseases are discussed within this context. Colonic adaptation has not been adequately studied, especially with modern microbiological techniques. Full article

(This article belongs to the Special Issue Lactose Intolerance: Biology, Genetics and Dietary Management)

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594 KiB

Open AccessArticle

Acute and Chronic Effects of Dietary Lactose in Adult Rats Are not Explained by Residual Intestinal Lactase Activity

by Bert J. M. van De Heijning, Diane Kegler, Lidewij Schipper, Eline Voogd, Annemarie Oosting and Eline M. van der Beek

Nutrients 2015, 7(7), 5542-5555; https://0-doi-org.brum.beds.ac.uk/10.3390/nu7075237 - 08 Jul 2015

Cited by 14 | Viewed by 6939

Abstract

Neonatal rats have a high intestinal lactase activity, which declines around weaning. Yet, the effects of lactose-containing products are often studied in adult animals. This report is on the residual, post-weaning lactase activity and on the short- and long-term effects of lactose exposure [...] Read more.

Neonatal rats have a high intestinal lactase activity, which declines around weaning. Yet, the effects of lactose-containing products are often studied in adult animals. This report is on the residual, post-weaning lactase activity and on the short- and long-term effects of lactose exposure in adult rats. Acutely, the postprandial plasma response to increasing doses of lactose was studied, and chronically, the effects of a 30% lactose diet fed from postnatal (PN) Day 15 onwards were evaluated. Intestinal lactase activity, as assessed both in vivo and in vitro, was compared between both test methods and diet groups (lactose vs. control). A 50%–75% decreased digestive capability towards lactose was observed from weaning into adulthood. Instillation of lactose in adult rats showed disproportionally low increases in plasma glucose levels and did not elicit an insulin response. However, gavages comprising maltodextrin gave rise to significant plasma glucose and insulin responses, indicative of a bias of the adult GI tract to digest glucose polymers. Despite the residual intestinal lactase activity shown, a 30% lactose diet was poorly digested by adult rats: the lactose diet rendered the animals less heavy and virtually devoid of body fat, whereas their cecum tripled in size, suggesting an increased bacterial fermentation. The observed acute and chronic effects of lactose exposure in adult rats cannot be explained by the residual intestinal lactase activity assessed. Full article

(This article belongs to the Special Issue Lactose Intolerance: Biology, Genetics and Dietary Management)

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Review

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1567 KiB

Open AccessReview

Diagnosing and Treating Intolerance to Carbohydrates in Children

by Roberto Berni Canani, Vincenza Pezzella, Antonio Amoroso, Tommaso Cozzolino, Carmen Di Scala and Annalisa Passariello

Nutrients 2016, 8(3), 157; https://0-doi-org.brum.beds.ac.uk/10.3390/nu8030157 - 10 Mar 2016

Cited by 50 | Viewed by 23843

Abstract

Intolerance to carbohydrates is relatively common in childhood, but still poorly recognized and managed. Over recent years it has come to the forefront because of progresses in our knowledge on the mechanisms and treatment of these conditions. Children with intolerance to carbohydrates often [...] Read more.

Intolerance to carbohydrates is relatively common in childhood, but still poorly recognized and managed. Over recent years it has come to the forefront because of progresses in our knowledge on the mechanisms and treatment of these conditions. Children with intolerance to carbohydrates often present with unexplained signs and symptoms. Here, we examine the most up-to-date research on these intolerances, discuss controversies relating to the diagnostic approach, including the role of molecular analysis, and provide new insights into modern management in the pediatric age, including the most recent evidence for correct dietary treatment. Full article

(This article belongs to the Special Issue Lactose Intolerance: Biology, Genetics and Dietary Management)

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Open AccessReview

Lactose Intolerance in Adults: Biological Mechanism and Dietary Management

by Yanyong Deng, Benjamin Misselwitz, Ning Dai and Mark Fox

Nutrients 2015, 7(9), 8020-8035; https://0-doi-org.brum.beds.ac.uk/10.3390/nu7095380 - 18 Sep 2015

Cited by 230 | Viewed by 68662

Abstract

Lactose intolerance related to primary or secondary lactase deficiency is characterized by abdominal pain and distension, borborygmi, flatus, and diarrhea induced by lactose in dairy products. The biological mechanism and lactose malabsorption is established and several investigations are available, including genetic, endoscopic and [...] Read more.

Lactose intolerance related to primary or secondary lactase deficiency is characterized by abdominal pain and distension, borborygmi, flatus, and diarrhea induced by lactose in dairy products. The biological mechanism and lactose malabsorption is established and several investigations are available, including genetic, endoscopic and physiological tests. Lactose intolerance depends not only on the expression of lactase but also on the dose of lactose, intestinal flora, gastrointestinal motility, small intestinal bacterial overgrowth and sensitivity of the gastrointestinal tract to the generation of gas and other fermentation products of lactose digestion. Treatment of lactose intolerance can include lactose-reduced diet and enzyme replacement. This is effective if symptoms are only related to dairy products; however, lactose intolerance can be part of a wider intolerance to variably absorbed, fermentable oligo-, di-, monosaccharides and polyols (FODMAPs). This is present in at least half of patients with irritable bowel syndrome (IBS) and this group requires not only restriction of lactose intake but also a low FODMAP diet to improve gastrointestinal complaints. The long-term effects of a dairy-free, low FODMAPs diet on nutritional health and the fecal microbiome are not well defined. This review summarizes recent advances in our understanding of the genetic basis, biological mechanism, diagnosis and dietary management of lactose intolerance. Full article

(This article belongs to the Special Issue Lactose Intolerance: Biology, Genetics and Dietary Management)

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Open AccessReview

The Interrelationships between Lactose Intolerance and the Modern Dairy Industry: Global Perspectives in Evolutional and Historical Backgrounds

by Nissim Silanikove, Gabriel Leitner and Uzi Merin

Nutrients 2015, 7(9), 7312-7331; https://0-doi-org.brum.beds.ac.uk/10.3390/nu7095340 - 31 Aug 2015

Cited by 153 | Viewed by 32364

Abstract

Humans learned to exploit ruminants as a source of milk about 10,000 years ago. Since then, the use of domesticated ruminants as a source of milk and dairy products has expanded until today when the dairy industry has become one of the largest [...] Read more.

Humans learned to exploit ruminants as a source of milk about 10,000 years ago. Since then, the use of domesticated ruminants as a source of milk and dairy products has expanded until today when the dairy industry has become one of the largest sectors in the modern food industry, including the spread at the present time to countries such as China and Japan. This review analyzes the reasons for this expansion and flourishing. As reviewed in detail, milk has numerous nutritional advantages, most important being almost an irreplaceable source of dietary calcium, hence justifying the effort required to increase its consumption. On the other hand, widespread lactose intolerance among the adult population is a considerable drawback to dairy-based foods consumption. Over the centuries, three factors allowed humans to overcome limitations imposed by lactose intolerance: (i) mutations, which occurred in particular populations, most notably in the north European Celtic societies and African nomads, in which carriers of the lactose intolerance gene converted from being lactose intolerant to lactose tolerant; (ii) the ability to develop low-lactose products such as cheese and yogurt; and (iii) colon microbiome adaptation, which allow lactose intolerant individuals to overcome its intolerance. However, in a few examples in the last decade, modern dairy products, such as the popular and widespread bio-cultured yogurts, were suspected to be unsuitable for lactose intolerant peoples. In addition, the use of lactose and milk-derived products containing lactose in non-dairy products has become widespread. For these reasons, it is concluded that it might be important and helpful to label food that may contain lactose because such information will allow lactose intolerant groups to control lactose intake within the physiological limitations of ~12 g per a single meal. Full article

(This article belongs to the Special Issue Lactose Intolerance: Biology, Genetics and Dietary Management)

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Open AccessReview

Milk Intolerance, Beta-Casein and Lactose

by Sebely Pal, Keith Woodford, Sonja Kukuljan and Suleen Ho

Nutrients 2015, 7(9), 7285-7297; https://0-doi-org.brum.beds.ac.uk/10.3390/nu7095339 - 31 Aug 2015

Cited by 108 | Viewed by 44643

Abstract

True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows’ milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of [...] Read more.

True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows’ milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows’ milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows’ milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed. Full article

(This article belongs to the Special Issue Lactose Intolerance: Biology, Genetics and Dietary Management)

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280 KiB

Open AccessReview

The Diverse Forms of Lactose Intolerance and the Putative Linkage to Several Cancers

by Mahdi Amiri, Lena Diekmann, Maren Von Köckritz-Blickwede and Hassan Y. Naim

Nutrients 2015, 7(9), 7209-7230; https://0-doi-org.brum.beds.ac.uk/10.3390/nu7095332 - 28 Aug 2015

Cited by 35 | Viewed by 11384

Abstract

Lactase-phlorizin hydrolase (LPH) is a membrane glycoprotein and the only β-galactosidase of the brush border membrane of the intestinal epithelium. Besides active transcription, expression of the active LPH requires different maturation steps of the polypeptide through the secretory pathway, including N- and [...] Read more.

Lactase-phlorizin hydrolase (LPH) is a membrane glycoprotein and the only β-galactosidase of the brush border membrane of the intestinal epithelium. Besides active transcription, expression of the active LPH requires different maturation steps of the polypeptide through the secretory pathway, including N- and O-glycosylation, dimerization and proteolytic cleavage steps. The inability to digest lactose due to insufficient lactase activity results in gastrointestinal symptoms known as lactose intolerance. In this review, we will concentrate on the structural and functional features of LPH protein and summarize the cellular and molecular mechanism required for its maturation and trafficking. Then, different types of lactose intolerance are discussed, and the molecular aspects of lactase persistence/non-persistence phenotypes are investigated. Finally, we will review the literature focusing on the lactase persistence/non-persistence populations as a comparative model in order to determine the protective or adverse effects of milk and dairy foods on the incidence of colorectal, ovarian and prostate cancers. Full article

(This article belongs to the Special Issue Lactose Intolerance: Biology, Genetics and Dietary Management)

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