A Small In Vitro Fermentation Model for Screening the Gut Microbiota Effects of Different Fiber Preparations.

The development of prebiotic fibers requires fast high-throughput screening of their effects on the gut microbiota. We demonstrated the applicability of a mictotiter plate in the in vitro fermentation models for the screening of potentially-prebiotic dietary fibers. The effects of seven rye bran-, oat- and linseed-derived fiber preparations on the human fecal microbiota composition and short-chain fatty acid production were studied. The model was also used to study whether fibers can alleviate the harmful effects of amoxicillin-clavulanate on the microbiota. The antibiotic induced a shift in the bacterial community in the absence of fibers by decreasing the relative amounts of Bifidobacteriaceae, Bacteroidaceae, Prevotellaceae, Lachnospiraceae and Ruminococcaceae, and increasing proteobacterial Sutterilaceae levels from 1% to 11% of the total microbiota. The fermentation of rye bran, enzymatically treated rye bran, its insoluble fraction, soluble oat fiber and a mixture of rye fiber:soluble oat fiber:linseed resulted in a significant increase in butyrate production and a bifidogenic effect in the absence of the antibiotic. These fibers were also able to counteract the negative effects of the antibiotic and prevent the decrease in the relative amount of bifidobacteria. Insoluble and soluble rye bran fractions and soluble oat fiber were the best for controlling the level of proteobacteria at the level below 2%.

Considerations for best practices in studies of fiber or other dietary components and the intestinal microbiome.

A 2-day workshop organized by the National Institutes of Health and U.S. Department of Agriculture included 16 presentations focused on the role of diet in alterations of the gastrointestinal microbiome, primarily that of the colon. Although thousands of research projects have been funded by U.S. federal agencies to study the intestinal microbiome of humans and a variety of animal models, only a minority addresses dietary effects, and a small subset is described in sufficient detail to allow reproduction of a study. Whereas there are standards being developed for many aspects of microbiome studies, such as sample collection, nucleic acid extraction, data handling, etc., none has been proposed for the dietary component; thus this workshop focused on the latter specific point. It is important to foster rigor in design and reproducibility of published studies to maintain high quality and enable designs that can be compared in systematic reviews. Speakers addressed the influence of the structure of the fermentable carbohydrate on the microbiota and the variables to consider in design of studies using animals, in vitro models, and human subjects. For all types of studies, strengths and weaknesses of various designs were highlighted, and for human studies, comparisons between controlled feeding and observational designs were discussed. Because of the lack of published, best-diet formulations for specific research questions, the main recommendation is to describe dietary ingredients and treatments in as much detail as possible to allow reproduction by other scientists.

The performance of five fruit-derived and freeze-dried potentially probiotic Lactobacillus strains in apple, orange, and grape juices.

BACKGROUND: This study assessed the survival of the fruit-derived and freeze-dried L. plantarum 49, L. brevis 59, L. paracasei 108, L. fermentum 111 and L. pentosus 129 strains during frozen storage and when incorporated into apple, orange, and grape juice stored under refrigeration. Physicochemical parameters of juices containing the freeze-dried Lactobacillus strains and the survival of the test strains in the fruit juices during in vitro digestion were also evaluated. RESULTS: No decreases in survival rates (log N/log N0) of the freeze-dried cells were observed in up to 1 month of storage. The survival rates of the freeze-dried strains L. plantarum 49 and L. paracasei 108 were > 0.75 in up to 4 months of storage. All freeze-dried strains exhibited survival rates of >0.75 in up to 2 weeks of storage in apple juice; only L. plantarum 49 and L. paracasei 108 showed similar survival rates in orange and grape juices in up to 2 weeks of storage. The contents of the monitored organic acids or sugars during storage varied depending on the added strain and the type of fruit juice. At the end of in vitro digestion, L. brevis 59, L. paracasei 108 and L. fermentum 111 showed survival rates of >0.80 in apple juice. CONCLUSION: Apple juice was the best substrate for the survival of the tested freeze-dried Lactobacillus strains over time. L. paracasei 108 and L. plantarum 49 were the strains presenting the best performance for incorporation in potentially probiotic fruit juices. © 2018 Society of Chemical Industry.

Metabolome and fecal microbiota in monozygotic twin pairs discordant for weight: a Big Mac challenge.

Postprandial responses to food are complex, involving both genetic and environmental factors. We studied postprandial responses to a Big Mac meal challenge in monozygotic co-twins highly discordant for body weight. This unique design allows assessment of the contribution of obesity, independent of genetic liability. Comprehensive metabolic profiling using 3 analytical platforms was applied to fasting and postprandial serum samples from 16 healthy monozygotic twin pairs discordant for weight (body mass index difference >3 kg/m(2)). Nine concordant monozygotic pairs were examined as control pairs. Fecal samples were analyzed to assess diversity of the major bacterial groups by using 5 different validated bacterial group specific denaturing gradient gel electrophoresis methods. No differences in fecal bacterial diversity were detected when comparing co-twins discordant for weight (ANOVA, P<0.05). We found that within-pair similarity is a dominant factor in the metabolic postprandial response, independent of acquired obesity. Branched chain amino acids were increased in heavier as compared with leaner co-twins in the fasting state, but their levels converged postprandially (paired t tests, FDR q<0.05). We also found that specific bacterial groups were associated with postprandial changes of specific metabolites. Our findings underline important roles of genetic and early life factors in the regulation of postprandial metabolite levels.

Contribution of diet to the composition of the human gut microbiota.

In the human gut, millions of bacteria contribute to the microbiota, whose composition is specific for every individual. Although we are just at the very beginning of understanding the microbiota concept, we already know that the composition of the microbiota has a profound impact on human health. A key factor in determining gut microbiota composition is diet. Preliminary evidence suggests that dietary patterns are associated with distinct combinations of bacteria in the intestine, also called enterotypes. Western diets result in significantly different microbiota compositions than traditional diets. It is currently unknown which food constituents specifically promote growth and functionality of beneficial bacteria in the intestine. The aim of this review is to summarize the recently published evidence from human in vivo studies on the gut microbiota-modulating effects of diet. It includes sections on dietary patterns (e.g. Western diet), whole foods, food constituents, as wells as food-associated microbes and their influence on the composition of human gut microbiota. The conclusions highlight the problems faced by scientists in this fast-developing field of research, and the need for high-quality, large-scale human dietary intervention studies.

Safety and efficacy of a feed additive consisting of 6-phytase produced with Trichoderma reesei (CBS 126897) (Quantum® Blue) for fin fish (ROAL Oy).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of 6-phytase (Quantum® Blue) as a zootechnical feed additive for fin fish. The additive is authorised for use in poultry and pigs. The additive is available in solid and liquid forms, and the 6-phytase contained in the product is produced by fermentation with a genetically modified strain of Trichoderma reesei. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the genetic modification of the production strain does not give rise to safety concerns; viable cells of the production strain and its DNA were not detected in the final products. The FEEDAP Panel concluded that, based on the data available, the additive tested is safe for fin fish at the highest recommended level of 2500 phytase activity unit (FTU)/kg complete feed. The Panel concluded that Quantum® Blue is not an irritant to skin and eyes nor a skin sensitiser. Owing to the proteinaceous nature of the active substance, 6-phytase (Quantum® Blue) is considered a respiratory sensitiser. The use of Quantum® Blue as a feed additive is considered safe for the environment. The additive is considered to be efficacious as a zootechnical additive for salmonids and ornamental fish at 500 FTU/kg complete feed and other fin fish at 2500 FTU/kg complete feed.

Assessment of the feed additive consisting of Limosilactobacillus fermentumNCIMB 30169 for all animal species for the renewal of its authorisation (Microferm Ltd.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application of renewal of Limosilactobacillus fermentum NCIMB 30169 as a technological feed additive (functional group: silage additives) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing terms of the authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers, and the environment. Regarding user safety, the additive should be considered a skin and respiratory sensitiser. No conclusions can be drawn on the eye irritancy potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lentilactobacillus buchneriATCC PTA-6138 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lentilactobacillus buchneri ATCC PTA-6138 as a technological additive (functional group: silage additives) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing terms of the authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers and the environment. Regarding user safety, the additive should be considered as a skin and respiratory sensitiser. No conclusions could be drawn on the eye irritancy potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lentilactobacillus buchneriATCC PTA-2494 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lentilactobacillus buchneri ATCC PTA-2494 as a technological additive (functional group: silage additives) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing terms of the authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers and the environment. Regarding user safety, the Panel considers that any exposure through skin and respiratory tract is considered a risk. The Panel cannot conclude on the eye irritation potential of the additive due to the lack of data. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Habitual dietary intake is associated with stool microbiota composition in monozygotic twins.

The impact of diet on the gut microbiota has usually been assessed by subjecting people to the same controlled diet and thereafter following the shifts in the microbiota. In the present study, we used habitual dietary intake, clinical data, quantitative polymerase chain reaction, and denaturing gradient gel electrophoresis (DGGE) to characterize the stool microbiota of Finnish monozygotic twins. The effect of diet on the numbers of bacteria was described through a hierarchical linear mixed model that included the twin individuals, stratified by body mass index, and their families as random effects. The abundance and diversity of the bacterial groups studied did not differ between normal-weight, overweight, and obese individuals with the techniques used. Intakes of energy, monounsaturated fatty acids, n3 polyunsaturated fatty acids (PUFAs), n6 PUFAs, and soluble fiber had significant associations with the stool bacterial numbers (e.g., increased energy intake was associated with reduced numbers of Bacteroides spp.). In addition, co-twins with identical energy intake had more similar numbers and DGGE-profile diversities of Bacteroides spp. than did the co-twins with different intake. Moreover, the co-twins who ingested the same amounts of saturated fatty acids had very similar DGGE profiles of Bacteroides spp., whereas the co-twins with similar consumption of fiber had a very low bifidobacterial DGGE-profile similarity. In conclusion, our findings confirm that the diet plays an important role in the modulation of the stool microbiota, in particular Bacteroides spp. and bifidobacteria.

Assessment of the feed additive consisting of Levilactobacillus brevis DSM 23231 for all animal species for the renewal of its authorisation (Biomin GmbH).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Levilactobacillus brevis (formerly Lactobacillus brevis) DSM 23231 as a technological feed additive for all animal species. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that evidence has been provided that the additive currently on the market complies with the existing terms of authorisation. The Panel also concluded that L. brevis DSM 23231 remains safe for all animal species, consumers and the environment under the authorised conditions of use. The additive should be considered a respiratory sensitiser. Based on the studies submitted regarding user safety, the preparation of the additive tested was shown not to be a skin or eye irritant. The Panel was not in the position to conclude on the skin sensitisation potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) NCIMB 30084 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on assessment of the application for renewal of authorisation Lactiplantibacillus plantarum (previously Lactobacillus) NCIMB 30084 as a technological feed additive, silage additive for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. There is no new evidence that would lead the FEEDAP Panel to reconsider its previous conclusions. Thus, the Panel concludes that the additive remains safe for all animal species, consumers and the environment under the authorised conditions of use. Regarding user safety, the additive should be considered as a respiratory sensitiser. No conclusions can be drawn on the skin sensitisation, and skin and eye irritancy potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of a feed additive containing Enterococcus lactis NCIMB 11181 (Lactiferm®) for weaned piglets, calves for fattening and calves for rearing for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of the authorisation of Enterococcus lactis NCIMB 11181 (Lactiferm®) as a zootechnical additive for weaned piglets, calves for fattening and calves for rearing. The product under assessment is based on a strain originally identified as Enterococcus faecium. During the current assessment, the active agent has been reclassified as Enterococcus lactis. The additive currently authorised is marketed in two formulations: Lactiferm Basic 50 (a solid formulation to be used in feed), and Lactiferm WS200 (a solid 'water-soluble' formulation to be used in water for drinking). The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The Panel concludes that the use of Lactiferm® under the authorised conditions of use remains safe for the target species (calves up to 6 months and weaned piglets up to 35 kg), consumers and the environment. The Lactiferm WS200 formulation of the additive is not irritant to skin or eyes. Owing to the proteinaceous nature of the active agent, both formulations of the additive are considered respiratory sensitisers. It is not possible to conclude on the irritating potential for skin and eyes of the Lactiferm Basic 50 formulation or on the potential of both forms of the additive to cause skin sensitisation. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Safety and efficacy of a feed additive consisting of endo-1,4-beta-xylanase produced by Trichoderma reesei ATCC PTA-5588, protease produced by Bacillus subtilis CBS 148232, and alpha-amylase produced by Bacillus licheniformis ATCC SD-6525 (Axtra® XAP 104 TPT) for chickens for fattening, laying hens and minor poultry species (Genencor international B.V.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of endo-1,4-beta-xylanase produced by Trichoderma reesei ATCC PTA-5588, protease produced by Bacillus subtilis CBS 148232, and alpha-amylase produced by Bacillus licheniformis ATCC SD-6525, Axtra® XAP 104 TPT, for chickens for fattening, laying hens and minor poultry species. In the previous assessment, a series of shortcomings did not allow to conclude on the safety of the product. The shortcomings included uncertainty on the presence of viable cells of one of the production strains; uncertainty on the identity of the production strains of the ■■■■■ used in the manufacturing process of the protease and their presence in the final additive; and uncertainty about the test item used for the toxicological testing of the xylanase. Moreover, the Panel could not conclude on the efficacy in laying hens. The applicant submitted some new information to address some of the limitations previously identified. Moreover, the applicant declared a change in the production strain of the protease, substituting B. subtilis ATCC SD-2107 for B. subtilis CBS 148232. The Panel concluded that the additive is safe for the target species at the recommended use level (1,000 xylanase U, 100 amylase U and 2,000 protease U per kg feed). The additive is safe for the consumers of food products obtained from animals fed with the additive and raises no concerns for the environment. The Panel could not conclude on the skin/eye irritancy potential of the additive nor on its dermal sensitisation potential. Owing to the proteinaceous nature of the active substances, the additive is considered a respiratory sensitiser. The additive is efficacious in chickens for fattening, chickens reared for laying and minor poultry species up to the point of lay at the level of 2,000 xylanase U, 200 amylase U and 4,000 protease U per kg feed (double the minimum recommended use level). Owing to the lack of sufficient data, the Panel could not conclude on the efficacy of the additive for laying hens.

Assessment of the feed additive consisting of Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) NCIMB 30083 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the assessment of the application for renewal of authorisation of Lactiplantibacillus plantarum (previously Lactobacillus plantarum) NCIMB 30083 as a technological additive, silage additive for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. There is no evidence that would lead the FEEDAP Panel to reconsider its previous conclusions. Thus, the Panel concluded that the additive remains safe for all animal species, consumers and the environment under the authorised conditions of use. Regarding user safety, the additive should be considered as a respiratory sensitiser. No conclusions can be drawn on the skin sensitisation, and skin and eye irritancy potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Safety and efficacy of a feed additive consisting of monensin sodium (Elancoban® G200) for chickens for fattening, chickens reared for laying and turkeys (Elanco GmbH).

Following a request from the European Commission, EFSA was asked to deliver a new scientific opinion on the coccidiostat monensin sodium (Elancoban® G200) when used as a feed additive for chickens for fattening and turkeys. Based on the new data provided, the Panel updates its previous conclusions as follows: monensin sodium is produced by fermentation by a non-genetically modified strain of Streptomyces sp. NRRL B-67924. Genome analysis suggests the production strain may belong to a new species within the genus Streptomyces. The production strain and its DNA were not detected in the final additive. The product is free of antimicrobial activity other than monensin. The FEEDAP Panel cannot conclude on the safety of monensin sodium from Elancoban® G200 in feed for chickens for fattening and chickens reared for laying at the proposed maximum use level due to a dose-related reduction of the final body weight. The toxicological profile of monensin sodium was evaluated in studies made with the product obtained from the parental strain ATCC 15413. Based on a comparison of the genomes of the two strains, the FEEDAP Panel concludes that toxicological equivalence has been established, thus the conclusions already drawn on Elancoban® G200 are valid for the product obtained with the new production strain concluding that the additive is safe for the consumer and the environment; the production strain does not represent an additional risk when safety for the user is considered. Monensin sodium from Elancoban® G200 is safe for turkeys up to 16 weeks of age at the concentration of 100 mg monensin sodium/kg feed and has the potential to control coccidiosis at the minimum concentration of 60 mg/kg complete feed.

Metabolic regulation in progression to autoimmune diabetes.

Recent evidence from serum metabolomics indicates that specific metabolic disturbances precede ß-cell autoimmunity in humans and can be used to identify those children who subsequently progress to type 1 diabetes. The mechanisms behind these disturbances are unknown. Here we show the specificity of the pre-autoimmune metabolic changes, as indicated by their conservation in a murine model of type 1 diabetes. We performed a study in non-obese prediabetic (NOD) mice which recapitulated the design of the human study and derived the metabolic states from longitudinal lipidomics data. We show that female NOD mice who later progress to autoimmune diabetes exhibit the same lipidomic pattern as prediabetic children. These metabolic changes are accompanied by enhanced glucose-stimulated insulin secretion, normoglycemia, upregulation of insulinotropic amino acids in islets, elevated plasma leptin and adiponectin, and diminished gut microbial diversity of the Clostridium leptum group. Together, the findings indicate that autoimmune diabetes is preceded by a state of increased metabolic demands on the islets resulting in elevated insulin secretion and suggest alternative metabolic related pathways as therapeutic targets to prevent diabetes.

Assessment of the feed additive consisting of Lactococcus lactis DSM 11037 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lactococcus lactis DSM 11037, a technological additive to improve ensiling of forage for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. There is no new evidence that would lead the FEEDAP Panel to reconsider its previous conclusions. Thus, the Panel concludes that the additive remains safe for all animal species, consumer and the environment under the authorised conditions of use. Regarding user safety, the additive is not a skin and eye irritant but should be considered a respiratory sensitiser. In absence of data, the Panel cannot conclude on the skin sensitisation potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lactococcus lactis NCIMB 30117 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lactococcus lactis NCIMB 30117 as a technological additive for use in forage for all animal species. The additive aims to improve the production of silage and is authorised for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. There is no new evidence that would lead the FEEDAP Panel to reconsider its previous conclusions. Thus, the Panel concludes that the additive remains safe for all animal species, consumer and the environment under the authorised conditions of use. Regarding user safety, the additive should be considered as a respiratory sensitiser. No conclusions can be drawn on the skin sensitisation, and eye and skin irritancy potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Safety and efficacy of a feed additive consisting of Pediococcus pentosaceus DSM 32292 for all animal species (Marigot Ltd t/a Celtic Sea Minerals).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Pediococcus pentosaceus DSM 32292 as a technological additive for all animal species. The additive is intended to improve the production of silage at a proposed application rate of 5 × 107 colony forming units (CFU)/kg forage. The bacterial species P. pentosaceus is considered by EFSA to be suitable for the qualified presumption of safety (QPS) approach. As the identity of the strain has been established and no antimicrobial resistance determinants of concern were detected, the use of the strain as a silage additive is considered safe for livestock species, for consumers and for the environment. In the absence of data, the FEEDAP Panel cannot conclude on the potential of the additive to be a skin/eye irritant or a skin sensitiser. Given the proteinaceous nature of the active agent, the additive should be considered a respiratory sensitiser. The additive at the proposed application rate of 5 × 107 CFU/kg forage has the potential to improve the production of silages from moderately difficult to ensile forages.