Barbara Walther

Dr. Barbara Walther


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2013 in Advances in Nutrition
Verified
Journal Article
Open access
PDF file
BWBarbara Walther
Barbara Walther
JKJ. Philip Karl
J. Philip Karl
SBSarah L. Booth
Sarah L. Booth
PBPatrick Boyaval
Patrick Boyaval
Vitamin K exists in the food supply as phylloquinone, a plant-based form and as menaquinones (MKs), a collection of isoprenologues mostly originating from bacterial synthesis. Although multiple bacterial species used as starter cultures for food fermentations synthesize MK, relatively little is known about the presence and distribution of MK in the food supply and the relative contribution of MK to total dietary vitamin K intake. Dairy products may be a predominant source of dietary MK in many regions of the world, and there is recent interest in enhancing the MK content of dairy products through identification and selection of MK-producing bacteria in dairy fermentations. This interest is increased by emerging evidence that current dietary recommendations based on the classic role of vitamin K as an enzyme cofactor for coagulation proteins may not be optimal for supporting vitamin K requirements in extrahepatic tissues and that MK may have unique bioactivity beyond that as an enzyme cofactor. Observational studies have reported favorable associations between MK intake and bone and cardiovascular health. Although randomized trials have provided some evidence to support the beneficial effects of MK on bone, the evidence to date is not definitive, and randomized trials have not yet examined MK intake in relation to cardiovascular outcomes. Food production practices provide a means to enhance dietary MK availability and intake. However, parallel research is needed to optimize these production practices, develop comprehensive food MK content databases, and test hypotheses of unique beneficial physiological roles of MK beyond that achieved by phylloquinone.

28 October 2022 in Frontiers in Nutrition
Verified
Journal Article
Open access
BWBarbara Walther
Barbara Walther
DGDominik Guggisberg
Dominik Guggisberg
RBRené Badertscher
René Badertscher
LELotti Egger
Lotti Egger
RPReto Portmann
Reto Portmann
SRSerge Rezzi
Serge Rezzi
The high decline in liquid milk consumption in Western countries has been compensated by the increased consumption of processed dairy products and the rapidly increasing number of new plant-based beverages constantly introduced in the market, advertised as milk substitutes and placed on shelves near milk products. To provide better understanding about the nutritional value of these drinks compared with cow’s milk, 27 plant-based drinks of 8 different species and two milk samples were purchased from two big retailers in Switzerland, and their composition regarding protein, carbohydrate, fat, vitamin, and mineral contents and residue load [glyphosate, aminomethylphosphonic acid (AMPA), and arsenic] was analyzed quantitatively and qualitatively. Energy and nutrient intakes were calculated and compared with the dietary reference values for Germany, Austria and Switzerland (D-A-CH). In addition, the digestible indispensable amino acid score (DIAAS) was calculated to estimate the quality of the proteins. Milk contained more energy; fat; carbohydrate; vitamins C, B2, B12, and A; biotin; pantothenic acid; calcium; phosphorus; and iodine than most plant-based drinks. Soy drinks provided slightly more protein and markedly more vitamins B1 and B6, folic acid, and vitamins E and D2 (with supplemented vitamin D2) and K1, magnesium, manganese, iron, and copper than milk and the other plant-based drinks. However, with the exception of cow’s milk and soy drinks, which had > 3% protein, most milk alternatives contained ≤ 1% protein; therefore, they cannot be considered good protein sources. In regard to protein quality, milk was outstanding compared with all plant-based drinks and exhibited higher calculated DIAASs. Our results show that the analyzed plant-based drinks are not real alternatives to milk in terms of nutrient composition, even if the actual fortification is taken into account. Improved fortification is still an issue and can be optimized using the most bioavailable and soluble derivatives. Complete replacement of milk with plant-based drinks without adjusting the overall diet can lead to deficiencies of certain important nutrients in the long term.

4 April 2018 in Nutrients
Verified
Journal Article
Open access
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DGDoreen Gille
Doreen Gille
ASAlexandra Schmid
Alexandra Schmid
BWBarbara Walther
Barbara Walther
GVGuy Vergères
Guy Vergères
Fermented foods represent a significant fraction of human diets. Although their impact on health is positively perceived, an objective evaluation is still missing. We have, therefore, reviewed meta-analyses of randomized controlled trials (RCT) investigating the relationship between fermented foods and non-transmissible chronic diseases. Overall, after summarizing 25 prospective studies on dairy products, the association of fermented dairy with cancer was found to be neutral, whereas it was weakly beneficial, though inconsistent, for specific aspects of cardio-metabolic health, in particular stroke and cheese intake. The strongest evidence for a beneficial effect was for yoghurt on risk factors of type 2 diabetes. Although mechanisms explaining this association have not been validated, an increased bioavailability of insulinotropic amino acids and peptides as well as the bacterial biosynthesis of vitamins, in particular vitamin K2, might contribute to this beneficial effect. However, the heterogeneity in the design of the studies and the investigated foods impedes a definitive assessment of these associations. The literature on fermented plants is characterized by a wealth of in vitro data, whose positive results are not corroborated in humans due to the absence of RCTs. Finally, none of the RCTs were specifically designed to address the impact of food fermentation on health. This question should be addressed in future human studies.

1 March 2018 in Journal of Trace Elements in Medicine and Biology
Verified
Journal Article
Open access
BWBarbara Walther
Barbara Walther
DWDaniel Wechsler
Daniel Wechsler
PSPatrick Schlegel
Patrick Schlegel
MHMax Haldimann
Max Haldimann
The iodine content in milk depends on various factors, including the season, production system, and location of milk production. The aim of this study was 1) to obtain data on the iodine concentration of conventional and organically produced milk and according to seasons; 2) to compare these actual data with previous measurement data; 3) to study the influence of UHT treatment on the iodine content and 4) to estimate the contribution of organic and conventional milk to the consumer's iodine intake. A total of 110 samples of conventional and organic ultra-heat treated (UHT) whole milk were collected in the period between 1 May 2013 and 30 April 2014 from two large-scale companies, processing milk from two regions in Switzerland. The iodine concentration in organic milk (average 71 ± 25 μg/l) was significantly lower than in conventional milk (average 111 ± 26 μg/l) and varied between suppliers. Milk iodine concentration varied according to the month of collection in organic and conventionally produced milk, with lowest values between August and October (organic milk 42 μg/l; conventional milk 75 μg/l) and highest values in January (organic milk 99 μg/l; conventional milk 145 μg/l). Heat treatment did not influence iodine concentration. Since milk and dairy products are significant source of food-related iodine intake in Switzerland, consumers who prefer organic milk and dairy products are likely to have an inferior iodine status.

29 April 2021 in Nutrients
Verified
Journal Article
Open access
PDF file
Millie PorziMillie Porzi
Millie Porzi
KBKathryn J Burton
Kathryn J Burton
BWBarbara Walther
Barbara Walther
GVGuy Vergères
Guy Vergères
Recent discoveries in the “omics” field and the growing focus on preventive health have opened new avenues for personalized nutrition (PN), which is becoming an important theme in the strategic plans of organizations that are active in healthcare, food, and nutrition research. PN holds great potential for individual health optimization, disease management, public health interventions, and product innovation. However, there are still multiple challenges to overcome before PN can be truly embraced by the public and healthcare stakeholders. The diagnosis and management of lactose intolerance (LI), a common condition with a strong inter-individual component, is explored as an interesting example for the potential role of these technologies and the challenges of PN. From the development of genetic and metabolomic LI diagnostic tests that can be carried out in the home, to advances in the understanding of LI pathology and individualized treatment optimization, PN in LI care has shown substantial progress. However, there are still many research gaps to address, including the understanding of epigenetic regulation of lactase expression and how lactose is metabolized by the gut microbiota, in order to achieve better LI detection and effective therapeutic interventions to reverse the potential health consequences of LI.

1 June 2016 in Clinical Nutrition
Verified
Journal Article
Closed access
DGDoreen Gille
Doreen Gille
UBUeli Bütikofer
Ueli Bütikofer
MCMagali Chollet
Magali Chollet
ASAlexandra Schmid
Alexandra Schmid
Themistoklis AltintzoglouThemistoklis Altintzoglou
Themistoklis Altintzoglou
PPPatrizia Piccinali
Patrizia Piccinali