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Shrestha A, Barnett MPG, Perry JK, Cameron-Smith D, Milan AM. Evaluation of breath, plasma, and urinary markers of lactose malabsorption to diagnose lactase non-persistence following lactose or milk ingestion. BMC Gastroenterol 2020; 20:204. [PMID: 32600320 PMCID: PMC7325051 DOI: 10.1186/s12876-020-01352-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/17/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Adult lactase non-persistence (LNP) is due to low lactase expression, resulting in lactose malabsorption (LM). LNP is a genetic trait, but is typically determined by LM markers including breath H2, blood glucose, and urinary galactose after a lactose tolerance test. Known validity of these markers using milk is limited, despite being common practice. Compositional variation, such as β-casein variants, in milk may impact diagnostic efficacy. This study aimed to evaluate the diagnostic accuracy to detect LNP using these commonly measured LM markers after both lactose and milk challenges. METHODS Fourty healthy young women were challenged with 50 g lactose then randomized for separate cross-over visits to ingest 750 mL milk (37.5 g lactose) as conventional (both A1 and A2 β-casein) and A1 β-casein-free (a2 Milk™) milk. Blood, breath and urine were collected prior to and up to 3 h following each challenge. The presence of C/T13910 and G/A22018 polymorphisms, determined by restriction fragment length polymorphism, was used as the diagnostic reference for LNP. RESULTS Genetic testing identified 14 out of 40 subjects as having LNP (C/C13910 and G/G22018). All three LM markers (breath H2, plasma glucose and urinary galactose/creatinine) discriminated between lactase persistence (LP) and LNP following lactose challenge with an area under the receiver operating characteristic (ROC) curve (AUC) of 1.00, 0.75 and 0.73, respectively. Plasma glucose and urinary galactose/creatinine were unreliable (AUC < 0.70) after milk ingestion. The specificity of breath H2 remained high (100%) when milk was used, but sensitivity was reduced with conventional (92.9%) and a2 Milk™ (78.6%) compared to lactose (sensitivities adjusted for lactose content). The breath H2 optimal cut-off value was lower with a2 Milk™ (13 ppm) than conventional milk (21 ppm). Using existing literature cut-off values the sensitivity and specificity of breath H2 was greater than plasma glucose to detect LNP following lactose challenge whereas values obtained for urinary galactose/creatinine were lower than the existing literature cut-offs. CONCLUSION This study showed accurate diagnosis of LNP by breath H2 irrespective of the substrate used, although the diagnostic threshold may vary depending on the lactose substrate or the composition of the milk. TRIAL REGISTRATION ACTRN12616001694404 . Registered prospectively on December 9, 2016.
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Affiliation(s)
- Aahana Shrestha
- The Liggins Institute, The University of Auckland, Auckland, New Zealand
- The Riddet Institute, Palmerston North, New Zealand
| | - Matthew P G Barnett
- The Riddet Institute, Palmerston North, New Zealand
- Food Nutrition & Health Team, AgResearch Limited, Palmerston North, New Zealand
- The High-Value Nutrition National Science Challenge, Auckland, New Zealand
| | - Jo K Perry
- The Liggins Institute, The University of Auckland, Auckland, New Zealand
| | - David Cameron-Smith
- The Liggins Institute, The University of Auckland, Auckland, New Zealand
- The Riddet Institute, Palmerston North, New Zealand
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
| | - Amber M Milan
- The Liggins Institute, The University of Auckland, Auckland, New Zealand.
- Food Nutrition & Health Team, AgResearch Limited, Palmerston North, New Zealand.
- The High-Value Nutrition National Science Challenge, Auckland, New Zealand.
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Summer A, Di Frangia F, Ajmone Marsan P, De Noni I, Malacarne M. Occurrence, biological properties and potential effects on human health of β-casomorphin 7: Current knowledge and concerns. Crit Rev Food Sci Nutr 2020; 60:3705-3723. [PMID: 32033519 DOI: 10.1080/10408398.2019.1707157] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The genetic variant A1 of bovine β-casein (β-Cn) presents a His residue at a position 67 of the mature protein. This feature makes the Ile66-His67 bond more vulnerable to enzymatic cleavage, determining the release of the peptide β-Cn f(60-66), named β-casomorphin 7 (BCM7). BCM7 is an opioid-agonist for μ receptors, and it has been hypothesized to be involved in the development of different non-transmissible diseases in humans. In the last decade, studies have provided additional results on the potential health impact of β-Cn A1 and BCM7. These studies, here reviewed, highlighted a relation between the consumption of β-Cn A1 (and its derivative BCM7) and the increase of inflammatory response as well as discomfort at the gastrointestinal level. Conversely, the role of BCM7 and the effects of ingestion of β-Cn A1 on the onset or worsening of other non-transmissible diseases as caused or favored by still need proof of evidence. Overall, the reviewed literature demonstrates that the "β-Cn A1/BCM7 issue" remains an intriguing but not exhaustively explained topic in human nutrition. On this basis, policies in favor of breeding for β-Cn variants not releasing BCM7 and consumption of "A1-like" milk appear not yet sound for a healthier and safer nutrition.
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Affiliation(s)
- Andrea Summer
- Department of Veterinary Sciences, Università di Parma, Parma, Italy
| | | | - Paolo Ajmone Marsan
- Department of Animal Science, Food and Nutrition (DIANA) and Nutrigenomics and Proteomics Research Center (PRONUTRIGEN), Università Cattolica del Sacro Cuore, Piacenza, Italy
| | - Ivano De Noni
- Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy
| | - Massimo Malacarne
- Department of Veterinary Sciences, Università di Parma, Parma, Italy
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Milan AM, Shrestha A, Karlström HJ, Martinsson JA, Nilsson NJ, Perry JK, Day L, Barnett MPG, Cameron-Smith D. Comparison of the impact of bovine milk β-casein variants on digestive comfort in females self-reporting dairy intolerance: a randomized controlled trial. Am J Clin Nutr 2020; 111:149-160. [PMID: 31773165 DOI: 10.1093/ajcn/nqz279] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 10/16/2019] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Lactose malabsorption (LM) is a major cause of digestive discomfort from dairy products. Recently, a role for bovine β-casein A1 has been proposed. OBJECTIVES We examined whether there are distinct symptoms of digestive discomfort due to either lactose or differing bovine β-casein types. METHODS Women (n = 40; age: 25.2 ± 0.5 y) with self-reported varying dairy tolerance underwent a 50-g lactose challenge. Based on postchallenge LM and digestive discomfort, participants were classified as either lactose intolerant (LI; n = 10, self-reported intolerant, diagnosed lactose intolerant), nonlactose dairy intolerant (NLDI; n = 20, self-reported intolerant, diagnosed lactose tolerant), or dairy tolerant (DT; n = 10, self-reported tolerant, diagnosed lactose tolerant). In a double-blinded randomized sequence, participants consumed 750 mL conventional milk (CON; containing A1 and A2 β-casein and lactose), a2 Milk (A2M; exclusively containing A2 β-casein with lactose), or lactose-free conventional milk (LF-CON; containing A1 and A2 β-casein without lactose). Subjective digestive symptoms and breath hydrogen (measuring LM) were recorded regularly over 3 h, and further ad hoc digestive symptoms over 12 h. RESULTS LI subjects experienced prolonged digestive discomfort with CON milk. A2M reduced (P < 0.05) some symptoms (nausea: A2M 8 ± 3 mm compared with CON 15 ± 3mm; fecal urgency: A2M 4 ± 1 compared with CON 10 ± 3 mm), and attenuated the rise in breath hydrogen over 3 h, relative to CON milk (A2M 59 ± 23 compared with CON 98 ± 25 ppm at 150 min; P < 0.01). In contrast, NLDI subjects experienced rapid-onset, transient symptoms (abdominal distension, bloating, and flatulence) without increased breath hydrogen, irrespective of milk type. CONCLUSIONS In LI individuals, LM and digestive comfort with lactose-containing milks was improved with milk containing exclusively A2 β-casein. Furthermore, self-reported dairy intolerance without LM (NLDI) is characterized by early-onset digestive discomfort following milk ingestion, irrespective of lactose content or β-casein type. This trial was registered at www.anzctr.org.au as ACTRN12616001694404.
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Affiliation(s)
- Amber M Milan
- The Liggins Institute, The University of Auckland, Auckland, New Zealand
| | - Aahana Shrestha
- The Liggins Institute, The University of Auckland, Auckland, New Zealand
| | | | | | | | - Jo K Perry
- The Liggins Institute, The University of Auckland, Auckland, New Zealand
| | - Li Day
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Matthew P G Barnett
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
- Riddet Institute, Palmerston North, New Zealand
- The High-Value Nutrition National Science Challenge, Auckland, New Zealand
| | - David Cameron-Smith
- The Liggins Institute, The University of Auckland, Auckland, New Zealand
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
- Riddet Institute, Palmerston North, New Zealand
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Schettini GP, Lambert SM, da Silva Souza BMP, Costa RB, de Camargo GMF. Genetic potential of Sindhi cattle for A2 milk production. ANIMAL PRODUCTION SCIENCE 2020. [DOI: 10.1071/an18677] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
ContextCow milk is consumed in many countries. However, its consumption can be associated with gastrointestinal disorders in humans. The genetic profile of β-casein is one of the factors responsible for these disorders and the A1 variant is a causal agent. The β-casein A1 leads to the formation of bioactive peptides, which trigger intestinal reactions. The same is not observed for the A2 allele. A2 milk is obtained from cows with the A2A2 genotype. The identification of breeds and selection of animals for A2 milk production is important for public health and animal production. The Sindhi cattle (Bos taurus indicus) possesses characteristics such as adaptation to hot climate, resistance to parasites and utilisation of low-quality forage that are important for rearing in the tropics.
AimsThe objective of the present study was to genotype the single-nucleotide polymorphism (SNP) that forms A1 and A2 alleles of the β-casein in Sindhi cattle.
MethodsIn total, 348 Sindhi animals were used. DNA was extracted from hair follicles and submitted to PCR-sequencing for genotyping.
Key resultsAllele frequency for A2 was 0.94 and for A1 it was 0.06. Genotype frequencies were 0.90 (A2A2), 0.09 (A1A2) and 0.01 (A1A1). The frequency of the A2A2 genotype in Sindhi cattle was similar to or higher than those found in zebu breeds and higher than those reported for specialised taurine breeds.
ConclusionsThis high frequency of the A2A2 genotype indicates a genetic potential of the breed for A2 milk production and easy, assisted selection (if that is the intention).
ImplicationsThis information gives importance to the breed and permits to add value to dairy product derived from it. It may increase producer’s income through producing and marketing A2 milk.
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Dalziel JE, Dunstan KE, Dewhurst H, Van Gendt M, Young W, Carpenter E. Goat milk increases gastric emptying and alters caecal short chain fatty acid profile compared with cow milk in healthy rats. Food Funct 2020; 11:8573-8582. [DOI: 10.1039/d0fo01862g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Goat and cow milk share similar protein and lipid content, yet goat milk forms softer curds during stomach digestion.
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Affiliation(s)
- Julie E. Dalziel
- Food Nutrition & Health Team
- Food & Bio-Based Products Group
- AgResearch
- Palmerston North 4442
- New Zealand
| | - Kelly E. Dunstan
- Food Nutrition & Health Team
- Food & Bio-Based Products Group
- AgResearch
- Palmerston North 4442
- New Zealand
| | - Hilary Dewhurst
- Food Nutrition & Health Team
- Food & Bio-Based Products Group
- AgResearch
- Palmerston North 4442
- New Zealand
| | - Melanie Van Gendt
- Food Nutrition & Health Team
- Food & Bio-Based Products Group
- AgResearch
- Palmerston North 4442
- New Zealand
| | - Wayne Young
- Food Nutrition & Health Team
- Food & Bio-Based Products Group
- AgResearch
- Palmerston North 4442
- New Zealand
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Aslam H, Ruusunen A, Berk M, Loughman A, Rivera L, Pasco JA, Jacka FN. Unravelled facets of milk derived opioid peptides: a focus on gut physiology, fractures and obesity. Int J Food Sci Nutr 2019; 71:36-49. [PMID: 31154909 DOI: 10.1080/09637486.2019.1614540] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Beyond being a source of key nutrients, bovine milk influences physiological functions by synthesising bioactive peptides during the process of digestion. Some of the claimed negative health outcomes associated with milk consumption, such as cardiovascular diseases and type 1 diabetes may be attributed to an opioid peptide, beta-casomorphin-7 (BCM-7), derived from A1 beta-casein. BCM-7 exerts its function by binding to the μ-opioid receptors in the body. It is hypothesised that activation of the μ-opioid receptors in the gut can alter gut microbial composition, impair gut barrier integrity and bile acid metabolism, in addition to increasing gastrointestinal transit time and gut inflammation. Further, it is hypothesised that BCM-7 may influence fractures and obesity via μ-opioid receptor pathways. In conclusion, it appears that BCM-7 might have multiple functions pertinent to human health; however, the evidence is limited and warrants further pre-clinical and clinical studies for hypothesis confirmation.
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Affiliation(s)
- Hajara Aslam
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, Geelong, Australia
| | - Anu Ruusunen
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, Geelong, Australia.,Department of Psychiatry, Kuopio University Hospital, Kuopio, Finland.,Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | - Michael Berk
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, Geelong, Australia.,Department of Psychiatry, Orygen Youth Health Research Centre and the Centre of Youth Mental Health, The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.,Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia.,Barwon Health, Geelong, Australia
| | - Amy Loughman
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, Geelong, Australia
| | - Leni Rivera
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, Geelong, Australia.,Metabolic Research Unit, School of Medicine, Waurn Ponds, Deakin University Victoria, Geelong, Australia
| | - Julie A Pasco
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, Geelong, Australia.,Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia.,Barwon Health, Geelong, Australia.,Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St Albans, Australia
| | - Felice N Jacka
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, Geelong, Australia.,Department of Psychiatry, University of Melbourne, Melbourne, Australia.,Centre for Adolescent Health, Murdoch Children's Research Institute, Melbourne, Australia.,Black Dog Institute, New South Wales, Australia
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Kumar A, Singh RV, Chauhan A, Ilayakumar K, Kumar S, Kumar A, Sonwane A, Kumar S, Panigrahi M, Bhushan B. Genetic association analysis reveals significant effect of β-casein A1/A2 loci on production & reproduction traits in Frieswal crossbred cows. BIOL RHYTHM RES 2019. [DOI: 10.1080/09291016.2019.1571705] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Adesh Kumar
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
| | - Ran Vir Singh
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
| | - Anuj Chauhan
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
| | - K Ilayakumar
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
| | - Sushil Kumar
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
| | - Amit Kumar
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
| | - Arvind Sonwane
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
| | - Subodh Kumar
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
| | - Manjit Panigrahi
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
| | - Bharat Bhushan
- Division of Animal Genetics, ICAR - Indian Veterinary Research Institute, Bareilly, India
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Dietary Cows' Milk Protein A1 Beta-Casein Increases the Incidence of T1D in NOD Mice. Nutrients 2018; 10:nu10091291. [PMID: 30213104 PMCID: PMC6163334 DOI: 10.3390/nu10091291] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/06/2018] [Accepted: 09/08/2018] [Indexed: 12/20/2022] Open
Abstract
The contribution of cows’ milk containing beta-casein protein A1 variant to the development of type 1 diabetes (T1D) has been controversial for decades. Despite epidemiological data demonstrating a relationship between A1 beta-casein consumption and T1D incidence, direct evidence is limited. We demonstrate that early life exposure to A1 beta-casein through the diet can modify progression to diabetes in non-obese diabetic (NOD) mice, with the effect apparent in later generations. Adult NOD mice from the F0 generation and all subsequent generations (F1 to F4) were fed either A1 or A2 beta-casein supplemented diets. Diabetes incidence in F0–F2 generations was similar in both cohorts of mice. However, diabetes incidence doubled in the F3 generation NOD mice fed an A1 beta-casein supplemented diet. In F4 NOD mice, subclinical insulitis and altered glucose handling was evident as early as 10 weeks of age in A1 fed mice only. A significant decrease in the proportion of non-conventional regulatory T cell subset defined as CD4+CD25−FoxP3+ was evident in the F4 generation of A1 fed mice. This feeding intervention study demonstrates that dietary A1 beta-casein may affect glucose homeostasis and T1D progression, although this effect takes generations to manifest.
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Asledottir T, Le TT, Poulsen NA, Devold TG, Larsen LB, Vegarud GE. Release of β-casomorphin-7 from bovine milk of different β-casein variants after ex vivo gastrointestinal digestion. Int Dairy J 2018. [DOI: 10.1016/j.idairyj.2017.12.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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He M, Sun J, Jiang ZQ, Yang YX. Effects of cow's milk beta-casein variants on symptoms of milk intolerance in Chinese adults: a multicentre, randomised controlled study. Nutr J 2017; 16:72. [PMID: 29070042 PMCID: PMC5657040 DOI: 10.1186/s12937-017-0275-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 08/24/2017] [Indexed: 02/07/2023] Open
Abstract
Background A major protein component of cow’s milk is β-casein. The most frequent variants in dairy herds are A1 and A2. Recent studies showed that milk containing A1 β-casein promoted intestinal inflammation and exacerbated gastrointestinal symptoms. However, the acute gastrointestinal effects of A1 β-casein have not been investigated. This study compared the gastrointestinal effects of milk containing A1 and A2 β-casein versus A2 β-casein alone in Chinese adults with self-reported lactose intolerance. Methods In this randomised, crossover, double-blind trial, with a 3-day dairy washout period at baseline, subjects were randomised to consume 300 mL of milk containing A1 and A2 β-casein (ratio 58:42; conventional milk) or A2 β-casein alone; subjects consumed the alternative product after a 7-day washout period. Urine galactose was measured at baseline after a 15 g lactose load. Subjects completed 9-point visual analogue scales for gastrointestinal symptoms (borborygmus, flatulence, bloating, abdominal pain, stool frequency, and stool consistency) at baseline and at 1, 3, and 12 h after milk consumption. Results A total of 600 subjects were included. All six symptom scores at 1 and 3 h were significantly lower after consuming A2 β-casein versus conventional milk (all P<0.0001). At 12 h, significant differences remained for bloating, abdominal pain, stool frequency, and stool consistency (all P<0.0001). Symptom scores were consistently lower with A2 β-casein in both lactose absorbers (urinary galactose ≥0.27 mmol/L) and lactose malabsorbers (urinary galactose <0.27 mmol/L). Conclusion Milk containing A2 β-casein attenuated acute gastrointestinal symptoms of milk intolerance, while conventional milk containing A1 β-casein reduced lactase activity and increased gastrointestinal symptoms compared with milk containing A2 β-casein. Thus, milk-related gastrointestinal symptoms may result from the ingestion of A1 β-casein rather than lactose in some individuals. Trial registration NCT02878876, registered August 16, 2016. Retrospectively registered. Electronic supplementary material The online version of this article (10.1186/s12937-017-0275-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mei He
- Beijing Research Institute for Nutritional Resources, Beijing, China
| | - Jianqin Sun
- Clinical Nutrition Center, Huadong Hospital Affiliated to Fudan University, Shanghai, China
| | - Zhuo Qin Jiang
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, China
| | - Yue Xin Yang
- Department of Food Nutrition, National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, China. .,Chinese Nutrition Society, 6# Guang An Men Nei. Street, Fenghua Square, Building A, Unit 5, Room 1601/1602, Xuanwu District, Beijing, 100053, People's Republic of China.
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Brooke-Taylor S, Dwyer K, Woodford K, Kost N. Systematic Review of the Gastrointestinal Effects of A1 Compared with A2 β-Casein. Adv Nutr 2017; 8:739-748. [PMID: 28916574 PMCID: PMC5593102 DOI: 10.3945/an.116.013953] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
This is the first systematic review, to our knowledge, of published studies investigating the gastrointestinal effects of A1-type bovine β-casein (A1) compared with A2-type bovine β-casein (A2). The review is relevant to nutrition practice given the increasing availability and promotion in a range of countries of dairy products free of A1 for both infant and adult nutrition. In vitro and in vivo studies (all species) were included. In vivo studies were limited to oral consumption. Inclusion criteria encompassed all English-language primary research studies, but not reviews, involving milk, fresh-milk products, β-casein, and β-casomorphins published through 12 April 2017. Studies involving cheese and fermented milk products were excluded. Only studies with a specific gastrointestinal focus were included. However, inclusion was not delimited by specific gastrointestinal outcome nor by a specific mechanism. Inclusion criteria were satisfied by 39 studies. In vivo consumption of A1 relative to A2 delays intestinal transit in rodents via an opioid-mediated mechanism. Rodent models also link consumption of A1 to the initiation of inflammatory response markers plus enhanced Toll-like receptor expression relative to both A2 and nonmilk controls. Although most rodent responses are confirmed as opioid-mediated, there is evidence that dipeptidyl peptidase 4 stimulation in the jejunum of rodents is via a nonopioid mechanism. In humans, there is evidence from a limited number of studies that A1 consumption is also associated with delayed intestinal transit (1 clinical study) and looser stool consistency (2 clinical studies). In addition, digestive discomfort is correlated with inflammatory markers in humans for A1 but not A2. Further research is required in humans to investigate the digestive function effects of A1 relative to A2 in different populations and dietary settings.
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Affiliation(s)
| | - Karen Dwyer
- School of Medicine, Faculty of Health, Deakin University, Geelong, Victoria, Australia
| | - Keith Woodford
- Agri-Food Systems, Lincoln University, Lincoln, New Zealand; and
| | - Natalya Kost
- Research Center of Mental Health, Russian Academy of Medical Sciences, Moscow, Russia
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Identification of bioactive peptides and quantification of β-casomorphin-7 from bovine β-casein A1, A2 and I after ex vivo gastrointestinal digestion. Int Dairy J 2017. [DOI: 10.1016/j.idairyj.2017.03.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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63
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Iacovou M, Mulcahy EC, Truby H, Barrett JS, Gibson PR, Muir JG. Reducing the maternal dietary intake of indigestible and slowly absorbed short-chain carbohydrates is associated with improved infantile colic: a proof-of-concept study. J Hum Nutr Diet 2017. [PMID: 28631347 DOI: 10.1111/jhn.12488] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND To investigate if a low fermentable oligo-, di- and mono-saccharides and polyols (FODMAP) diet consumed by breastfeeding mothers may be associated with reduced symptoms of infantile colic. METHODS Exclusively breastfeeding mothers and their typically-developing healthy infants who met the Wessel Criteria for infantile colic were recruited from the community, to this single-blind, open-label, interventional study. After a 3-day qualifying period, mothers were provided a low FODMAP 7-day diet. On days 5, 6 and 7 mothers completed a Baby Day Diary. At baseline and at the end of the 7-day dietary intervention, breast milk was analysed for FODMAP content and infant faecal samples for pH. RESULTS Eighteen breastfeeding mothers (aged 27-40 years) adhered (100%) to the low FODMAP diet. Infants were of gestational age 37-40.3 weeks and aged 2-17 weeks. At entry, crying durations were a mean [95% CI] of 142 [106-61] min and fell by 52 [178-120] min (P = 0.005; ancova). Combined crying-fussing durations fell by 73 [301-223] min (n = 13; P = 0.007), as did crying episodes (P = 0.01) and fussing durations (P = 0.011). Infant sleeping, feeding, or awake-and-content durations did not change. Infant faecal pH did not change. Breast milk lactose content was stable and other known FODMAPs were not detected. At end of study, mothers reported their baby 'is much more content' and 'can be put down without crying'. CONCLUSIONS Maternal low FODMAP diet may be associated with a reduction in infant colic symptoms. A randomized controlled study is warranted to determine if a maternal low FODMAP diet is effective in reducing symptoms.
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Affiliation(s)
- M Iacovou
- Department of Gastroenterology, Central Clinical School, The Alfred Centre, Monash University, Melbourne, Vic., Australia
| | - E C Mulcahy
- Department of Gastroenterology, Central Clinical School, The Alfred Centre, Monash University, Melbourne, Vic., Australia
| | - H Truby
- Department of Nutrition, Dietetics and Food, Notting Hill, Vic., Australia
| | - J S Barrett
- Department of Gastroenterology, Central Clinical School, The Alfred Centre, Monash University, Melbourne, Vic., Australia
| | - P R Gibson
- Department of Gastroenterology, Central Clinical School, The Alfred Centre, Monash University, Melbourne, Vic., Australia
| | - J G Muir
- Department of Gastroenterology, Central Clinical School, The Alfred Centre, Monash University, Melbourne, Vic., Australia
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Chia JSJ, McRae JL, Kukuljan S, Woodford K, Elliott RB, Swinburn B, Dwyer KM. A1 beta-casein milk protein and other environmental pre-disposing factors for type 1 diabetes. Nutr Diabetes 2017; 7:e274. [PMID: 28504710 PMCID: PMC5518798 DOI: 10.1038/nutd.2017.16] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 02/20/2017] [Accepted: 03/01/2017] [Indexed: 12/14/2022] Open
Abstract
Globally type 1 diabetes incidence is increasing. It is widely accepted that the pathophysiology of type 1 diabetes is influenced by environmental factors in people with specific human leukocyte antigen haplotypes. We propose that a complex interplay between dietary triggers, permissive gut factors and potentially other influencing factors underpins disease progression. We present evidence that A1 β-casein cows’ milk protein is a primary causal trigger of type 1 diabetes in individuals with genetic risk factors. Permissive gut factors (for example, aberrant mucosal immunity), intervene by impacting the gut’s environment and the mucosal barrier. Various influencing factors (for example, breastfeeding duration, exposure to other dietary triggers and vitamin D) modify the impact of triggers and permissive gut factors on disease. The power of the dominant trigger and permissive gut factors on disease is influenced by timing, magnitude and/or duration of exposure. Within this framework, removal of a dominant dietary trigger may profoundly affect type 1 diabetes incidence. We present epidemiological, animal-based, in vitro and theoretical evidence for A1 β-casein and its β-casomorphin-7 derivative as dominant causal triggers of type 1 diabetes. The effects of ordinary milk containing A1 and A2 β-casein and milk containing only the A2 β-casein warrant comparison in prospective trials.
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Affiliation(s)
- J S J Chia
- Immunology Research Centre, St Vincent's Hospital Melbourne, Fitzroy, Victoria, Australia
| | - J L McRae
- Immunology Research Centre, St Vincent's Hospital Melbourne, Fitzroy, Victoria, Australia
| | - S Kukuljan
- Freedom Foods Group Ltd, Sydney, New South Wales, Australia
| | - K Woodford
- Agricultural Management Group, Lincoln University, Christchurch, New Zealand
| | - R B Elliott
- Living Cell Technologies, Auckland, New Zealand
| | - B Swinburn
- School of Population Health, University of Auckland, Auckland, New Zealand
| | - K M Dwyer
- Immunology Research Centre, St Vincent's Hospital Melbourne, Fitzroy, Victoria, Australia.,School of Medicine, Faculty of Health, Deakin University, Geelong, Victoria, Australia.,Department of Medicine, The University of Melbourne, Melbourne, Australia
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Kirk B, Mitchell J, Jackson M, Amirabdollahian F, Alizadehkhaiyat O, Clifford T. A2 Milk Enhances Dynamic Muscle Function Following Repeated Sprint Exercise, a Possible Ergogenic Aid for A1-Protein Intolerant Athletes? Nutrients 2017; 9:nu9020094. [PMID: 28134840 PMCID: PMC5331525 DOI: 10.3390/nu9020094] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/19/2017] [Accepted: 01/24/2017] [Indexed: 12/21/2022] Open
Abstract
Hyperaminoacidemia following ingestion of cows-milk may stimulate muscle anabolism and attenuate exercise-induced muscle damage (EIMD). However, as dairy-intolerant athletes do not obtain the reported benefits from milk-based products, A2 milk may offer a suitable alternative as it lacks the A1-protein. This study aimed to determine the effect of A2 milk on recovery from a sports-specific muscle damage model. Twenty-one male team sport players were allocated to three independent groups: A2 milk (n = 7), regular milk (n = 7), and placebo (PLA) (n = 7). Immediately following muscle-damaging exercise, participants consumed either A2 milk, regular milk or PLA (500 mL each). Visual analogue scale (muscle soreness), maximal voluntary isometric contraction (MVIC), countermovement jump (CMJ) and 20-m sprint were measured prior to and 24, 48, and 72 h post EIMD. At 48 h post-EIMD, CMJ and 20-m sprint recovered quicker in A2 (33.4 ± 6.6 and 3.3 ± 0.1, respectively) and regular milk (33.1 ± 7.1 and 3.3 ± 0.3, respectively) vs. PLA (29.2 ± 3.6 and 3.6 ± 0.3, respectively) (p < 0.05). Relative to baseline, decrements in 48 h CMJ and 20-m sprint were minimised in A2 (by 7.2 and 5.1%, respectively) and regular milk (by 6.3 and 5.2%, respectively) vs. PLA. There was a trend for milk treatments to attenuate decrements in MVIC, however statistical significance was not reached (p = 0.069). Milk treatments had no apparent effect on muscle soreness (p = 0.152). Following muscle-damaging exercise, ingestion of 500 mL of A2 or regular milk can limit decrements in dynamic muscle function in male athletes, thus hastening recovery and improving subsequent performance. The findings propose A2 milk as an ergogenic aid following EIMD, and may offer an alternative to athletes intolerant to the A1 protein.
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Affiliation(s)
- Ben Kirk
- School of Health Sciences, Liverpool Hope University, Hope Park, Liverpool L16 9JD, UK.
| | - Jade Mitchell
- Department of Sport, Exercise & Rehabilitation, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK.
| | - Matthew Jackson
- School of Health Sciences, Liverpool Hope University, Hope Park, Liverpool L16 9JD, UK.
| | | | - Omid Alizadehkhaiyat
- School of Health Sciences, Liverpool Hope University, Hope Park, Liverpool L16 9JD, UK.
| | - Tom Clifford
- Department of Sport, Exercise & Rehabilitation, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK.
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67
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Deth R, Clarke A, Ni J, Trivedi M. Clinical evaluation of glutathione concentrations after consumption of milk containing different subtypes of β-casein: results from a randomized, cross-over clinical trial. Nutr J 2016; 15:82. [PMID: 27680716 PMCID: PMC5041571 DOI: 10.1186/s12937-016-0201-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/15/2016] [Indexed: 12/17/2022] Open
Abstract
Abstract This study reports the plasma glutathione concentrations in a double-blind, randomized, controlled, 2 × 2 cross-over study in which healthy participants consumed conventional milk (2 × 250 mL per day) containing both A1 and A2 types of β-casein, or milk containing only A2 type β-casein. Beta-casomorphin-7 (BCM-7), a peptide uniquely derived from the A1 type of β-casein, was previously reported to downregulate glutathione expression in human gut epithelial and neuronal cell lines by limiting cysteine uptake. The current human study demonstrates that consumption of milk containing only A2 β-casein was associated with a greater increase in plasma glutathione concentrations compared with the consumption of milk containing both β-casein types, and did not increase plasma BCM-7 concentrations compared with the washout diet in the study participants. Thus, milk containing only A2 β-casein and not A1 β-casein has the potential to promote the production of the antioxidant glutathione in humans. Clinical Trial Registration ClinicalTrials.gov; identifier: NCT02406469 Electronic supplementary material The online version of this article (doi:10.1186/s12937-016-0201-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Richard Deth
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Rm # 1382, Terry Building, Fort Lauderdale, FL, 33317, USA
| | | | - Jiayi Ni
- S.P.R.I.M. China (Shanghai) Consulting Co., Ltd., Shanghai, China
| | - Malav Trivedi
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Rm # 1382, Terry Building, Fort Lauderdale, FL, 33317, USA.
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68
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Jianqin S, Leiming X, Lu X, Yelland GW, Ni J, Clarke AJ. Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cows' milk. Nutr J 2016; 15:35. [PMID: 27039383 PMCID: PMC4818854 DOI: 10.1186/s12937-016-0147-z] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 03/14/2016] [Indexed: 02/06/2023] Open
Abstract
Background Cows’ milk generally contains two types of β-casein, A1 and A2 types. Digestion of A1 type can yield the peptide β-casomorphin-7, which is implicated in adverse gastrointestinal effects of milk consumption, some of which resemble those in lactose intolerance. This study aimed to compare the effects of milk containing A1 β-casein with those of milk containing only A2 β-casein on inflammation, symptoms of post-dairy digestive discomfort (PD3), and cognitive processing in subjects with self-reported lactose intolerance. Methods Forty-five Han Chinese subjects participated in this double-blind, randomized, 2 × 2 crossover trial and consumed milk containing both β-casein types or milk containing only A2 β-casein. Each treatment period was 14 days with a 14-day washout period at baseline and between treatment periods. Outcomes included PD3, gastrointestinal function (measured by smart pill), Subtle Cognitive Impairment Test (SCIT), serum/fecal laboratory biomarkers, and adverse events. Results Compared with milk containing only A2 β-casein, the consumption of milk containing both β-casein types was associated with significantly greater PD3 symptoms; higher concentrations of inflammation-related biomarkers and β-casomorphin-7; longer gastrointestinal transit times and lower levels of short-chain fatty acids; and increased response time and error rate on the SCIT. Consumption of milk containing both β-casein types was associated with worsening of PD3 symptoms relative to baseline in lactose tolerant and lactose intolerant subjects. Consumption of milk containing only A2 β-casein did not aggravate PD3 symptoms relative to baseline (i.e., after washout of dairy products) in lactose tolerant and intolerant subjects. Conclusions Consumption of milk containing A1 β-casein was associated with increased gastrointestinal inflammation, worsening of PD3 symptoms, delayed transit, and decreased cognitive processing speed and accuracy. Because elimination of A1 β-casein attenuated these effects, some symptoms of lactose intolerance may stem from inflammation it triggers, and can be avoided by consuming milk containing only the A2 type of beta casein. Trial registration ClinicalTrials.gov/NCT02406469 Electronic supplementary material The online version of this article (doi:10.1186/s12937-016-0147-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sun Jianqin
- Clinical Nutrition Center, Huadong Hospital affiliated to Fudan University, Shanghai, China
| | - Xu Leiming
- Department of Gastroenterology, Xin Hua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xia Lu
- Endoscopic Center, Shanghai Internal Medicine Center, Shanghai, China.
| | - Gregory W Yelland
- Department of Gastroenterology, Central Clinical School, The Alfred Centre, Monash University, Melbourne, VIC, Australia.,School of Health Sciences, RMIT University, Bundoora, VIC, Australia
| | - Jiayi Ni
- S.P.R.I.M. China (Shanghai) Consulting Co., Ltd., Shanghai, China
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69
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Caroli AM, Savino S, Bulgari O, Monti E. Detecting β-Casein Variation in Bovine Milk. Molecules 2016; 21:141. [PMID: 26821001 PMCID: PMC6273733 DOI: 10.3390/molecules21020141] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 12/30/2015] [Accepted: 01/18/2016] [Indexed: 11/16/2022] Open
Abstract
In bovine species, β-casein (β-CN) is characterized by genetic polymorphism. The two most common protein variants are β-CN A² (the original one) and A¹, differing from A² for one amino acid substitution (Pro67 to His67). Several bioactive peptides affecting milk nutritional properties can originate from β-CN. Among them, β-casomorphin-7 (BCM7) ranging from amino acid 60 to 66 can be released more easily from β-CN variants carrying His67 (A¹ type) instead of Pro67 (A² type). Nowadays, "A2 milk" is produced in different countries claiming its potential benefits in human health. The aim of this study was to further develop and apply an isoelectric focusing electrophoresis (IEF) method to bulk and individual milk samples in order to improve its use for β-CN studies. We succeeded in identifying A2 milk samples correctly and quantifying the percentage of A², A¹, and B variants in bulk samples not derived from A2 milk as well as in individual milk samples. The method allows us to quantify the relative proportion of β-CN variants in whole milk without eliminating whey protein by acid or enzymatic precipitation of caseins. The aim of this study was also to study the different behavior of β-CN and β-lactoglobulin (β-LG) in the presence of trichloroacetic acid (TCA). The higher sensitivity of β-CN to TCA allows quantifying β-CN variants after TCA fixation because β-LG is not visible. Monitoring β-CN variation in cattle breeds is important in order to maintain a certain balance between Pro67 and His67 in dairy products. Overall, the debate between A1 and A2 milk needs further investigation.
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Affiliation(s)
- Anna Maria Caroli
- Unit of Biotechnology, Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy.
| | - Salvatore Savino
- Unit of Biotechnology, Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy.
| | - Omar Bulgari
- Unit of Biotechnology, Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy.
| | - Eugenio Monti
- Unit of Biotechnology, Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy.
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Abstract
This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants). This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, United States.
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71
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Abstract
Milk has been considered as a natural source of nutrition for decades. Milk is known to be nutrient-rich which aids the growth and development of the human body. Milk contains both macro- and micronutrients. Breast milk is widely regarded as the optimal source of neonatal nutrition due to its composition of carbohydrates, proteins, minerals and antibodies. However, despite the wide use of milk products, investigations into the role of milk in degenerative diseases have been limited. This review will examine the relationship between the β-casein gene found in bovine milk and disease states by using age-related macular degeneration as an example.
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Pal S, Woodford K, Kukuljan S, Ho S. Milk Intolerance, Beta-Casein and Lactose. Nutrients 2015; 7:7285-97. [PMID: 26404362 PMCID: PMC4586534 DOI: 10.3390/nu7095339] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 08/12/2015] [Accepted: 08/21/2015] [Indexed: 12/24/2022] Open
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 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.
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Affiliation(s)
- Sebely Pal
- School of Public Health, Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth WA 6845, Australia.
| | - Keith Woodford
- Agricultural Management Group, Lincoln University, PO Box 85084, Lincoln 7647, Christchurch, New Zealand.
| | - Sonja Kukuljan
- The a2 Milk Company (Australia) Pty Ltd, PO Box 180, Kew East, Victoria 3102, Australia.
| | - Suleen Ho
- School of Public Health, Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth WA 6845, Australia.
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Abstract
BACKGROUND While it is well documented and widely appreciated that ingestion of wheat (and less so rye and barley) is associated with gastrointestinal symptoms such as bloating or abdominal pain, the component of wheat to which such an effect is attributed is less well established. KEY MESSAGES Wheat is a complex of proteins (80% gluten, 20% metabolic proteins), carbohydrates (starch, non-starch polysaccharides, fructans), lipids and other components. The majority of attention has focused on gluten as the culprit in triggering symptoms, but re-challenge studies have nearly all used wheat flour-related products (such as bread) as the stimulus. When carbohydrate-deplete gluten was used as the challenge agent, gluten-specific feelings of depression and not gut symptoms were observed in those who fulfilled strict criteria of 'non-coeliac gluten sensitivity', thereby underlining the complexity of cereals and of undertaking research in this area. Candidate components other than gluten include poorly absorbed oligosaccharides (mainly fructans), non-gluten wheat proteins such as amylase-trypsin inhibitors or wheat germ agglutinin, and exorphins released during the digestion of gluten. Specific biological and/or clinical effects associated with gluten-free diets or wheat ingestion need to be carefully dissected before attribution to gluten can be claimed. CONCLUSIONS Currently, coeliac disease is the only common condition that has been unequivocally linked to gluten. Inaccurate attribution will be associated with suboptimal therapeutic advice and at least partly underlies the current gluten-free epidemic gripping the Western world.
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Severance EG, Gressitt KL, Alaedini A, Rohleder C, Enning F, Bumb JM, Müller JK, Schwarz E, Yolken RH, Leweke FM. IgG dynamics of dietary antigens point to cerebrospinal fluid barrier or flow dysfunction in first-episode schizophrenia. Brain Behav Immun 2015; 44:148-58. [PMID: 25241021 PMCID: PMC4275312 DOI: 10.1016/j.bbi.2014.09.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/29/2014] [Accepted: 09/08/2014] [Indexed: 12/30/2022] Open
Abstract
Schizophrenia is a complex brain disorder that may be accompanied by idiopathic inflammation. Classic central nervous system (CNS) inflammatory disorders such as viral encephalitis or multiple sclerosis can be characterized by incongruent serum and cerebrospinal fluid (CSF) IgG due in part to localized intrathecal synthesis of antibodies. The dietary antigens, wheat gluten and bovine milk casein, can induce a humoral immune response in susceptible individuals with schizophrenia, but the correlation between the food-derived serological and intrathecal IgG response is not known. Here, we measured IgG to wheat gluten and bovine milk casein in matched serum and CSF samples from 105 individuals with first-episode schizophrenia (n=75 antipsychotic-naïve), and 61 controls. We found striking correlations in the levels of IgG response to dietary proteins between serum and CSF of schizophrenia patients, but not controls (schizophrenia, R(2)=0.34-0.55, p⩽0.0001; controls R(2)=0.05-0.06, p>0.33). A gauge of blood-CSF barrier permeability and CSF flow rate, the CSF-to-serum albumin ratio, was significantly elevated in cases compared to controls (p⩽0.001-0.003). Indicators of intrathecal IgG production, the CSF IgG index and the specific Antibody Index, were not significantly altered in schizophrenia compared to controls. Thus, the selective diffusion of bovine milk casein and wheat gluten antibodies between serum and CSF in schizophrenia may be the function of a low-level anatomical barrier dysfunction or altered CSF flow rate, which may be transient in nature.
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Affiliation(s)
- Emily G. Severance
- Stanley Division of Developmental Neurovirology, Department of Pediatrics, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Blalock 1105, Baltimore, MD 21287-4933 U.S.A,Correspondence: Emily G. Severance, , tel: +1 410-614-3918, fax: +1 410-955-3723
| | - Kristin L. Gressitt
- Stanley Division of Developmental Neurovirology, Department of Pediatrics, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Blalock 1105, Baltimore, MD 21287-4933 U.S.A
| | - Armin Alaedini
- Department of Medicine, Columbia University Medical Center, 1130 Saint Nicholas Ave., ICRC 901B, New York, NY, 10032 U.S.A
| | - Cathrin Rohleder
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Frank Enning
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany,Department of Psychosomatics and Psychotherapeutic Medicine, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - J. Malte Bumb
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Juliane K. Müller
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Emanuel Schwarz
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Robert H. Yolken
- Stanley Division of Developmental Neurovirology, Department of Pediatrics, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Blalock 1105, Baltimore, MD 21287-4933 U.S.A
| | - F. Markus Leweke
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Ho S, Woodford K, Kukuljan S, Pal S. Comparative effects of A1 versus A2 beta-casein on gastrointestinal measures: a blinded randomised cross-over pilot study. Eur J Clin Nutr 2014; 68:994-1000. [DOI: 10.1038/ejcn.2014.127] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/09/2014] [Accepted: 05/24/2014] [Indexed: 02/07/2023]
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