BACKGROUND & AIMS:Previous studies have described benefits and risks on human health associated with a vegan diet. Although it is recognized that diet affects the gut microbiota, there is no consensus on the effects of a vegan diet compared to omnivorous diet on the gut microbiota. We have conducted a pilot study to assess the differences between the gut microbiome of vegans and omnivores in 2017 and 2021. METHODS:Fecal samples of 23 vegans and 23 omnivores (n = 46) were collected in 2017 and 2021 together with more than 300 dietary, lifestyle, and health related characteristics. The fecal microbiome was assessed comparing both amplicon sequencing and metagenome sequencing, to determine robust signals agnostic of sequencing approaches. RESULTS:Dietary grouping itself explained a small (∼4 %) but significant proportion of the individual variation between microbiota. Natural clustering of microbiomes explained an even larger proportion. We found Ruminococcus torques to be relatively enriched in omnivores compared to vegans across methods and years. Interestingly, this species has been previously associated with unfavorable health outcomes. Despite a low sample size, we found some consistent differences between microbiota of individuals consuming either a vegan or omnivorous diet. CONCLUSIONS:These results were consistent with recently published gut microbiome signatures of vegans and omnivores across three different countries. Therefore, this small dataset allows a first insight into the gut microbiota of another county's omnivores and vegans whereby detailed and relevant dietary, lifestyle and health related characteristics collected in this study aid in understanding of the connection between respective diets and the microbiome.

Following a strict raw food diet (primarily based on fresh fruit and raw vegetables, waiving any consumption of heated or processed food) has the risk of undersupply of energy and certain macro- and micronutrients. In this cross-sectional study, we compared 16 non-smoking strict raw food eaters (5 women and 11 men, age 44.6 ± 12.3 years, duration of following the diet 11.6 ± 10.8 years) with the non-smoking participants (32 vegans, 27 omnivores) of the "Risk and Benefits of a Vegan Diet" (RBVD) study. We investigated body composition, dietary intake from 3-day weighed food records, and relevant fasting blood and serum parameters. Food choice and dietary behavior were very heterogenic in raw food eaters. They had lower mean values of BMI and percentage of body fat than the respective RBVD participants. The same holds true for energy supply and intakes of protein, carbohydrate, calcium and iodine. Serum levels revealed lower levels of HDL cholesterol, triglycerides, zinc, and vitamin D3. The raw food eaters with (n = 9) and without (n = 7) supplementation of vitamin B12 had median vitamin B12 levels of 399 and 152 ng/L, respectively. Accordingly, eight raw food eaters (50%) had homocysteine levels above 12 µmol/L. The study allows a close look at strict raw food eaters with respect to possible dietary deficiencies, but also provides insights into motivations and daily life.

It has been estimated that most vegans meet the total protein requirements, but whether this is also true for individual essential amino acids (AAs) is unclear. Furthermore, a shift in protein intake is suggested to alter microbiota composition, but this association is unknown in terms of veganism or individual AAs. This cross-sectional study compared vegans and omnivores regarding dietary intake and plasma concentration of AAs. The prevalence of insufficient intake of essential AAs among vegans was determined using estimated average requirements (EAR) of WHO. Moreover, correlations between AAs intake and gut microbiota were investigated. Data of 36 vegans and 36 omnivores (30–60 years) were analysed. AA intake, AA plasma concentrations and gut microbiota were ascertained by three-day weighed food protocols, gas/liquid chromatography-tandem mass spectrometry and 16S rRNA sequencing, respectively. At almost the same energy intake, the intake of 9 AAs in vegans was significantly lower than in omnivores, with median differences of − 27.0% to − 51.9%. However, only one female vegan showed total protein and lysine intake below the EAR. Vegans showed lower lysine (− 25.0%), but higher glycine (+ 25.4%) and glutamate (+ 13.1%) plasma concentrations than omnivores. Correlation patterns between AA intake and bacterial microbiota differed between vegans and omnivores. In vegans 19 species and in omnivores 5 species showed correlations with AA intake. Vegans consumed apparently sufficient but lower AAs than omnivores. In addition, the different AAs intake seems to influence the microbiota composition. The use of short-term dietary data without considering usual intake limits these findings.

ScopeFurfuryl alcohol is a heat‐induced food contaminant, classified as possibly carcinogenic to humans. The proximal carcinogen 2‐sulfoxymethylfuran leads to adduct formation in DNA and proteins (e.g., N‐((furan‐2‐yl)methyl)‐Val (FFA‐Val) in hemoglobin).Methods and resultsThis study analyzed human erythrocyte samples from two studies for the presence of FFA‐Val: the Risks and Benefits of a Vegan Diet study (RBVD; 72 adults) and the ENVIRonmental influence ON early AGEing birth cohort study (ENVIRONAGE; 100 mother‐newborn pairs). In the RBVD study, FFA‐Val levels are lower in vegans compared to omnivores (median 13.0 vs 15.8 pmol g−1 hemoglobin, p = 0.008), and lower in non‐smokers compared to smokers (median 14.1 vs 17.0 pmol g−1 hemoglobin, p = 0.003). In the birth cohort, FFA‐Val levels are distinctly higher in maternal compared to newborn samples (median 15.2 vs 2.2 pmol g−1 hemoglobin, p < 0.001).ConclusionsFFA‐Val, hitherto detected only in blood samples of mice, is quantifiable in all human samples, indicating a general exposure to furfuryl alcohol. The low adduct levels in blood samples from newborn children suggested that the placenta is a barrier to furfuryl alcohol. Dietary habits and tobacco smoking are two main influencing factors on the formation of FFA‐Val, which may be of use as a biomarker of exposure to furfuryl alcohol.

A vegan diet could impact microbiota composition and bacterial metabolites like short-chain (SCFA) and branched-chain fatty acids (BCFA). The aim of this study was to compare the concentrations of SCFA, BCFA, ammonia, and fecal pH between vegans and omnivores. In this cross-sectional study (vegans n = 36; omnivores n = 36), microbiota composition, fecal SCFA, BCFA, and ammonia concentrations and pH were analyzed in complete stool samples. A random forest regression (RFR) was used to identify bacteria predicting SCFA/BCFA concentrations in vegans and omnivores. No significant differences in SCFA and BCFA concentrations were observed between vegans and omnivores. Fecal pH (p = 0.005) and ammonia concentration (p = 0.01) were significantly lower in vegans than in omnivores, while fiber intake was higher (p < 0.0001). Shannon diversity was higher in omnivores compared to vegans on species level (p = 0.04) only. In vegans, a cluster of Faecalibacterium prausnitzii, Prevotella copri, Dialister spp., and Eubacterium spp. was predictive for SCFA and BCFA concentrations. In omnivores, Bacteroides spp., Clostridium spp., Ruminococcus spp., and Prevotella copri were predictive. Though SCFA and BCFA did not differ between vegans and omnivores, the results of the RFR suggest that bacterial functionality may be adapted to varying nutrient availability in these diets.

BACKGROUND:In Germany, public interest in a vegan diet is steadily growing. There are, however, no current data on the macro- and micronutrient status of vegans.METHODS:In a cross-sectional study entitled "The Risks and Benefits of a Vegan Diet" (RBVD), we investigated the dietary intake, basic laboratory parameters, vitamin status, and trace-element status of 36 vegans and 36 persons on an omnivorous diet. Each group consisted of 18 men and 18 women aged 30-60.RESULTS:Nearly all the vegans and one-third of the persons on a mixed diet had consumed supplements in the previous 4 weeks. Vegans and nonvegans had similar energy intake but differed in the intake of both macronutrients (e.g., dietary fiber) and micronutrients (e.g., vitamins B12, B2, D, E, and K, as well as folate, iodine, and iron). There were no intergroup differences in the biomarkers of vitamin B12, vitamin D, or iron status. The ferritin values and blood counts indicated iron deficiency in four vegans and three non-vegans. Measurements in 24-hour urine samples revealed lower calcium excretion and markedly lower iodine excretion in vegans compared to non-vegans; in one-third of the vegans, iodine excretion was lower than the WHO threshold value (<20 μg/L) for severe iodine deficiency.CONCLUSION:Vitamin B12 status was similarly good in vegans and non-vegans, even though the vegans consumed very little dietary B12. This may be due to the high rate of supplementation. The findings imply a need to also assure adequate iodine intake in the population, especially among persons on a vegan diet.

Bile acids play an active role in fat metabolism and, in high-fat diets, elevated concentrations of fecal bile acids may be related to an increased risk of colorectal cancer. This study investigated concentrations of fecal and serum bile acids in 36 vegans and 36 omnivores. The reduced rank regression was used to identify dietary patterns associated with fecal bile acids. Dietary patterns were derived with secondary and conjugated fecal bile acids as response variables and 53 food groups as predictors. Vegans had higher fiber (p < 0.01) and lower fat (p = 0.0024) intake than omnivores. In serum, primary and glycine-conjugated bile acids were higher in vegans than in omnivores (p ≤ 0.01). All fecal bile acids were significantly lower in vegans compared to omnivores (p < 0.01). Processed meat, fried potatoes, fish, margarine, and coffee contributed most positively, whereas muesli most negatively to a dietary pattern that was directly associated with all fecal bile acids. According to the pattern, fat intake was positively and fiber intake was inversely correlated with bile acids. The findings contribute to the evidence that, in particular, animal products and fat may play a part in higher levels of fecal bile acids.

It is assumed that diet influences the composition of gut microbiota, which in turn may affect human health status. This systematic review aimed to summarize associations of a vegan or vegetarian diet with the composition of microbiota. A literature search was conducted in PubMed and Embase for eligible human studies with vegan or vegetarian diets as an exposure and microbiota composition as an outcome in healthy adults. Furthermore, data from our cross-sectional study with vegan participants were included. Out of sixteen included studies, six investigated the association between gut microbiota composition in both vegans and in vegetarians, six in vegans and four studies in vegetarians compared to omnivores, respectively. Among 5 different phyla, 28 families, 96 genera and 177 species, Bacteroides, Bifidobacterium and Prevotella were the most reported genera, followed by the species Prevotella copri, Faecalibacterium prausnitzii and Escherichia coli in all diets. No consistent association between a vegan diet or vegetarian diet and microbiota composition compared to omnivores could be identified. Moreover, some studies revealed contradictory results. This result could be due to high microbial individuality, and/or differences in the applied approaches. Standardized methods with high taxonomical and functional resolutions are needed to clarify this issue.

About one third of the adults in Germany are using food supplements regularly. Besides vitamins and minerals, these products also contain other substances such as amino acids, fatty acids, plant extracts or microorganisms. Advertising promises positive effects for health, well-being and improved performance. Product safety issues are rarely discussed. Already in the year 2002, a directive (2002/46/EC) on the approximation of the laws of the EU Member States concerning food supplements was adopted, which also provides settings of maximum levels. Since then, different models for the quantitative derivation of maximum levels for vitamins and minerals have been developed and discussed in Germany and other European countries. However, to date no binding maximum levels for vitamins and minerals in food supplements have been set at EU level. Meanwhile, EU member states such as Denmark and France have adopted national regulations. Against this background, the Federal Institute for Risk Assessment (BfR) has developed proposals for maximum levels for vitamins and minerals in food supplements. Vitamin and mineral supplements which comply with these recommendations and are taken according to the manufacturer's instructions are safe for persons from 15 years of age.

In Deutschland greift etwa ein Drittel der Erwachsenen regelmäßig zu Nahrungsergänzungsmitteln (NEM). Neben Vitaminen und Mineralstoffen enthalten die Produkte teilweise auch sonstige Stoffe mit physiologischer Wirkung wie Aminosäuren, Fettsäuren, Pflanzenextrakte oder Mikroorganismen. Die Werbung verspricht positive Effekte für Gesundheit, Wohlbefinden und verbesserte Leistungsfähigkeit. Fragen zur Produktsicherheit werden selten thematisiert. Schon im Jahr 2002 wurde in der Europäischen Union (EU) eine Richtlinie (2002/46/EG) zur Angleichung der Rechtsvorschriften der Mitgliedstaaten über NEM erlassen, die auch die Festlegung von Höchstmengen vorsieht. In Deutschland und anderen europäischen Ländern wurden seither verschiedene Modelle für die Höchstmengenableitung für Vitamine und Mineralstoffe entwickelt und diskutiert. Bis heute wurden jedoch auf EU-Ebene keine verbindlichen Höchstmengen festgelegt. Länder wie Dänemark und Frankreich haben daher mittlerweile nationale Regelungen getroffen. Vor diesem Hintergrund hat das Bundesinstitut für Risikobewertung (BfR) auf Basis des derzeitigen wissenschaftlichen Kenntnisstandes Vorschläge für Vitamin- und Mineralstoffhöchstmengen in NEM erarbeitet. Produkte, die diese Empfehlungen einhalten und entsprechend den Herstelleranweisungen eingenommen werden, sind für Personen ab 15 Jahren sicher.

In Tabelle 1, erste Zeile, letzte Spalte (Bemerkungen zu Vitamin D) wurde angegeben, dass laut Gemeinsamer Expertenkommission von BVL/BfArM Vitamin D-haltige Präparate bis zu einer Tagesdosis von 20 µg noch als Nahrungsergänzungsmittel (NEM) eingestuft werden können, während Präparate mit höheren Dosierungen als Arzneimittel anzusehen sind (BVL/BfArM 2016).

In the study “Praxistest Diabetes” (PraDi) we investigated the application of the German Diabetes Risk Score (GDRS) and FINDRISK in health checkups in terms of the predictive ability to identify undiagnosed prediabetes and diabetes. 403 men and women aged 35–70 years participated in the PraDi study. The predictive ability of prediabetes/diabetes (fasting plasma glucose FPG ≥ 5.6 mmol/L) or diabetes (FPG ≥ 7.0 mmol/L) was evaluated with discrimination (area under the receiver-operating-characteristic curve [ROC-AUC]). With regard to blood glucose tests, 93 participants had prediabetes/diabetes and 7 participants had undiagnosed diabetes. The ROC-AUC for the GDRS for identification of prediabetes/diabetes was 0.78 (95% confidence interval [95%-CI]: 0.73–0.94) which was higher than observed for FINDRISK with 0.73 (95%-CI: 0.68–0.79; p = 0.029). The ROC-AUC for identification of diabetes was 0.83 (95%CI: 0.73–0.94) for the GDRS and 0.80 (95%-CI: 0.61–0.99) for FINDRISK (p = 0.67). In the context of health checkups, the GDRS showed a more precise identification of patients with prediabetes/diabetes or diabetes compared to FINDRISK.

Creatine is a popular ergogenic supplement in sports nutrition. Yet, supplementation of creatine occasionally caused adverse effects such as gastrointestinal complaints, muscle cramps and an increase in body weight. Creatine monohydrate has already been evaluated by different competent authorities and several have come to the conclusion that a daily intake of 3 g creatine per person is unlikely to pose safety concerns, focusing on healthy adults with exclusion of pregnant and breastfeeding women. Possible vulnerable subgroups were also discussed in relation to the safety of creatine. The present review provides an up-to-date overview of the relevant information with special focus on human studies regarding the safety of creatine monohydrate and other marketed creatine forms, in particular creatine pyruvate, creatine citrate, creatine malate, creatine taurinate, creatine phosphate, creatine orotate, creatine ethyl ester, creatine pyroglutamate, creatine gluconate, and magnesium creatine chelate. Limited data are available with regard to the safety of the latter creatine forms. Considering an acceptable creatine intake of 3 g per day, most of the evaluated creatine forms are unlikely to pose safety concerns, however some safety concerns regarding a supplementary intake of creatine orotate, creatine phosphate, and magnesium creatine chelate are discussed here.

Creatine is a popular ergogenic supplement in sports nutrition. Yet, supplementation of creatine occasionally caused adverse effects such as gastrointestinal complaints, muscle cramps and an increase in body weight. Creatine monohydrate has already been evaluated by different competent authorities and several have come to the conclusion that a daily intake of 3 g creatine per person is unlikely to pose safety concerns, focusing on healthy adults with exclusion of pregnant and breastfeeding women. Possible vulnerable subgroups were also discussed in relation to the safety of creatine. The present review provides an up‐to‐date overview of the relevant information with special focus on human studies regarding the safety of creatine monohydrate and other marketed creatine forms, in particular creatine pyruvate, creatine citrate, creatine malate, creatine taurinate, creatine phosphate, creatine orotate, creatine ethyl ester, creatine pyroglutamate, creatine gluconate, and magnesium creatine chelate. Limited data are available with regard to the safety of the latter creatine forms. Considering an acceptable creatine intake of 3 g per day, most of the evaluated creatine forms are unlikely to pose safety concerns, however some safety concerns regarding a supplementary intake of creatine orotate, creatine phosphate, and magnesium creatine chelate are discussed here.