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High-fat and low-fat fermented milk and cheese intake, proteomic signatures, and risk of all-cause and cause-specific mortality.

PURPOSE: This study aimed to examine the associations between the intake of high- and low-fat fermented dairy (cheese and fermented milk), their proteomic profiles, and mortality risk. METHODS: This cohort study included 25,187 participants (mean age 57.7 years, 60.9% females). Fermented dairy intake was assessed by a modified diet history method. In a random subset of this cohort (n&#x2009;=&#x2009;4359), we constructed proteomic signatures for fermented dairy intake using 136 candidate plasma proteins. RESULTS: During 23.5 years of follow-up, 9742 participants died. High-fat cheese (>&#x2009;20% fat) intake was inversely associated with risk of all-cause mortality (HR for an increment of 20&#xa0;g/day, 0.97; 95% CI, 0.96-0.99, P&#x2009;<&#x2009;0.001) and cardiovascular disease mortality (HR, 0.96; 95% CI, 0.93-0.99, P&#x2009;=&#x2009;0.006). Low-fat cheese intake showed an inverse association with all-cause mortality (HR, 0.98; 95% CI, 0.96-1.00, P&#x2009;=&#x2009;0.047). Low-fat fermented milk intake was inversely associated with all-cause mortality (HR for an increment of 250&#xa0;g/day, 0.91; 95% CI, 0.85-0.97, P&#x2009;=&#x2009;0.006), while high-fat fermented milk (>&#x2009;2.5% fat) showed null association. A total of 42, 26, 0, and 39 proteins were identified for the signature of high-fat cheese, low-fat cheese, high-fat fermented milk, and low-fat fermented milk, respectively. Inverse associations with all-cause mortality were observed for all three signatures with identified proteins. The identified proteins were involved in biological pathways related to immune response and inflammation. CONCLUSION: Our study indicated that consuming high-fat cheese, low-fat cheese, and low-fat fermented milk was linked to survival benefits. Plasma proteins improve our understanding of the health effects of fermented dairy.

Humans

Nutritional and healthful aspects of cultured and culture-containing dairy foods.

Nutritional and therapeutic qualities of fermented dairy products are reviewed. Partial hydrolysis of milk constituents (proteins, fats, and lactose) in yogurt, cheese, and other cultured dary foods appears to contribute to their increased digestibility. Lactase and other constituent enzymes of various culturing organisms should contribute to assimilation of lactose by lactose intolerant individuals. Several lactic cultures synthesize certain B-vitamins in fermented dairy products. In contrast, directly acidified dairy products do not exhibit such enhancement in B-vitamins. The hypocholestremic effect of milk is enhanced by fermentation or inclusion of lactic cultures. Lactobacillus acidophilus, Lactobacillus bulgaricus and other lactic organisms produce antimicrobial agents and natural antibiotics. However, production of natural antibacterial substances by different strains of the same species vary widely. These metabolites in cultured dairy products may be responsible for increased shelf life of the foods by inhibiting a wide spectrum of food spoilage organisms. Also, consumption of cultured products containing such natural antibacterial substances may provide the consumer with protection against disease organisms. Unfermented milk containing a specific culture or strain may be consumed to invest organisms for projected beneficial effects.

Animals

Genomic signatures of dairy adaptation in Saccharomyces cerevisiae from traditional Yaghnob goat-cheese fermentation.

The growing interest in studying Saccharomyces cerevisiae strains from previously unexplored niches is greatly expanding our understanding of this yeast's ecology and evolution. While strains involved in alcoholic fermentation are the most studied, S. cerevisiae has also been isolated from milk fermentations and their products, suggesting a potential evolutionary specialization for dairy environments. These fermentations are characterized by the predominant presence of lactose, a carbon source that S. cerevisiae cannot metabolize directly but can exploit through the enzymatic activity of co-occurring microorganisms that convert lactose into fermentable substrates, such as glucose and galactose. In this study, we analyzed S. cerevisiae strains isolated from an unexplored and remote niche: traditional goat fermented milk produced by the Yaghnob people, an ethnically and geographically partly isolated population living in the Upper Zarafshan area of the Republic of Tajikistan. Comparative analyses with published S. cerevisiae genomes positioned the Yaghnob strains at the base of the phylogenetic dairy clade. These strains revealed distinctive coding sequences and strain-specific single-nucleotide variants present in all Yaghnob strains but absent from the other 1,053 strains analyzed. Further investigation of variants in key genes involved in galactose metabolism provided insights into the genomic and protein-level evolution of Yaghnob strains, uncovering unique genomic signatures of adaptation to the dairy environment.

Saccharomyces cerevisiae

[Effect of production and storage on the survival of Staphylococcus aureus in curd].

The effect of curd production on the survival of staphylococci has been studied. At the begining of the manufacture process favourable conditions exist for the development of staphylococci. Their number decreases with the increasing acidity and in the final product they occur only sporadically or quite disappeare, especially when the curd is stored at cooling chamber temperatures. The lactose-positive staphylococci take part in the splitting of milk lactose and the production of milk acid as well. Their participation in this process is statistically significant. Some biochemical properties of the used Staphylococcus aureus strain as plasma koagulation, lecithinase, phosphatase and haemolytical toxin production, glucose, mannitol and lactose fermentation under aerobic and anaerobic conditions were studied. The biochemical properties of this strain do not change during the process of curd production.

Dairy Products

Utilization of lactose and production of corrinoids in selected strains of propionic acid bacteria in cheese-whey and casein media.

Comparative studies were carried out with 23 strains (14 species) of propionibacteria in two media-cheese-whey and casein. The degree of lactose fementation and the efficiency of the corrinoids synthesis were studied. Lactose fermentation showed great differences even within one species (e.g. 13.3% and 66.1% for various strains of P. shermanii). The differences were particularly sharp in casein medium (0% or 100%). The highest capacity for utilizing cheese-whey lactose (70--80%) was found in two strains of P. shermanii and P. petersonii and P. arabinosum. No definite correlation, however, was found either in the cheese-whey or in the casein medium, between the capability of lactose fermentation and the efficiency of the corrinoids. As the most technologically effective strains have been recognized P. shermanii 1, P. shermanii 566 and P. petersonii J.

Caseins

Microorganisms and characteristics of laban.

Laban had a titratable acidity of about 1.0%, a pH of 4.25, an ethanol content of 1.25%, and contained 4.2 mug acetaldehyde and 34 mug acetoin/ml. There was no diacetyl. Five microorganisms, classified as Streptococcus thermophilus, Lactobacillus acidophilus, Leuconostoc lactis, Kluyveromyces fragilis, and Saccharomyces cerevisiae, were responsible for the fermentation. Streptococcus thermophilus and L. acidophilus were responsible for acid production with S. thermophilus producing acid more rapidly. Most of the acetaldehyde was produced by K. fragilis, little ethanol was found in absence of S. cerevisiae, and the acetoin was producted by S. thermophilus.

Animals

Qualitative and quantitative changes in carbohydrates during the manufacture of yogurt.

The average lactose content of yogurt mix was 8.50% and decreased during fermentation to 5.75%. The initial galactose content of the mix was a trace but increased to 1.20% during fermentation. Glucose content remained a trace throughout fermentation. Several brands of commercial yogurt were purchased from local supermarkets and analyzed for carbohydrate content. Lactose ranged from 3.31 to 4.74%, galactose varied from 1.48 to 2.50%, and glucose was only a trace in all samples. Several samples of buttermilk also exhibited the near absence of glucose.

Carbohydrates

Integrated GC-HRAM-MS and UHPLC-QTOF-MS metabolomics reveal mineral-induced metabolic adaptation of Lactiplantibacillus pentosus 9D3 during milk fermentation.

Milk fermentation by plant-associated probiotic strains is constrained by poor adaptation to dairy matrices. This study evaluated genome-guided micronutrient supplementation to improve the performance and metabolomic profile of Lactiplantibacillus pentosus 9D3 in milk. Individual supplementation with Mn2+ or Mg2+ significantly enhanced bacterial growth and acidification, whereas Fe2+, Zn2+, and B-group vitamins showed limited effects. Optimal supplementation with 50&#xa0;mg/L Mn2+ and 100&#xa0;mg/L Mg2+ increased viable counts from 7.54 to 8.89 log CFU/mL. A cell population increase of &#x223c;1.9 log CFU/mL was achieved despite reducing the inoculum level from 10% to 6%. Integrated metabolomic profiling using GC-HRAM-MS and UHPLC-QTOF-MS identified 299 metabolites across supplemented fermented milk, non-supplemented fermented milk, and unfermented milk, with group separation. Pathway analysis revealed significant enrichment of seven metabolic pathways, including purine, pyrimidine, galactose, propanoate, butanoate, amino sugar and nucleotide sugar, and &#x3b1;-linolenic acid metabolism. These findings support cost-efficient precision fermentation of functional dairy products.

Dairy products

[The effect of pelleting cereal straw with NaOH-addition on rumen fermentation in cows].

Experiments with rumen-fistulated dairy cows were performed to study the effect of NaOH-addition to cereal pellets. Compared to straw-concentrate rations in which the straw pellets were free of NaOH, cereal straw pellets containing 2.4 kg NaOH per 100 kg straw caused the rumenal pH to go up from 6.21 to 6.47, the cellulotlytic activity to rise by some 20%, and the passage turnover rate of dry matter to increase from 0,039 to 0,056. The concentrations of volatile fatty acids and the fermentation patterns were not influenced by the NaOH-content of the pellets. It is concluded that NaOH-addition during straw pelleting has a favourable effect on digestion in the bovine rumen.

Animals

[Changes of the clinico-biochemical indices in the rumirid juice and urine in experimental aflatoxicosis of dairy cows].

The health condition and course of fermentation processes in the rumen were studied in four cows of the Red Spotted breed at the age of four to nine years. The clinico-biochemical indices in the rumen liquor and urine were used. The experimental animals were exposed to a mixture of aflatoxins applied in the dose of 200 mg B1 and 80 mg B2. The toxic action of aflatoxins manifested itself as inappetence, increased temperature, changes in the pulse and respiration rate and reduced activity of the proventriculi. Diarrhoea was observed in two animals. The pH value, total acidity and ammonia level in rumen liquor ranged within the limits of reference values. The significant drop of the production of volatile fatty acids with changes in their proportions and a reduction of the acetic acid level with a simultaneous increase of the percentage of butyric acid testity to a disorder in the activity of rumen microflora. The reduction of the number of infusorians as a biological indicator of fermentation processes proves the correctness of this assumption. During the elimination of aflatoxins through the kidneys the function of the kidneys is impaired, showed proteinuria, ketonuria, glycosuria and haematuria.

Acetates

Bacterial fermentation of cheese whey for production of a ruminant feed supplement rich in curde protein.

A simple and efficient process for the production of a ruminant feed supplement, rich in crude protein (defined as total N X 6.25), by bacterial fermentation of cheese whey has been developed. The lactose in unpasteurized whey is fermented to lactate acid by Lactobacillus bulgaricus at a temperature of 43 degrees C and pH 5.5. The lactic acid produced is continually neutralized with ammonia to form ammonium lactate. The fermented product is concentrated by evaporation to a solids content of about 70% and adjusted to pH 6.8 with additional ammonia. The concentrated product contains about 55% crude protein. Approximately 6 to 8% of the crude protein is derived from bacterial cells. 17% from whey proteins, and 75 to 77% from ammonium lactate. The efficiency of conversion of lactose to lactic acid usually exceeds 95%. The fermentation time is greatly reduced upon the addition of 0.2% yeast extract or 0.1% corn steep liquor as a source of growth factors. Whey containing lactose at concentrations up to 7% can be fermented efficiently, but at higher concentrations lactose is fermented incompletely. The process has been scaled up to a pilot plant level, and 40 tons of concentrated product were produced fro animal feeding trials, without ever encountering putrefactive spoilage.

Animal Feed

Enhancing the fiber degradation efficiency in dairy cattle rumen through engineered bacterial communities.

BACKGROUND: The rumen functions as an anaerobic fermentation chamber, housing microorganisms with cellulolytic and proteolytic capabilities that facilitate feed utilization. Fiber-degrading bacteria possess the capability to enhance the productivity of cellulolytic feed. The application of omics technologies has greatly improved our understanding of the rumen microbiome. Determining microbial composition and functional patterns in the rumen does not equate to a comprehensive exploration of rumen microbial resources and their mechanisms of action. This study seeks to integrate high throughput 16S rRNA data with information on culturomics, cellulolytic activities, nutrition, and synthetic microbial communities (SynCom) engineering. The objective is to evaluate the relationship between rumen microbial activity and fiber utilization efficiency in cattle, ultimately aiming to develop a more powerful intervention strategy for the ruminant industry. RESULTS: The enrichment culture with various carbon sources led to significant alterations in the composition and structure of rumen microbiota, particularly enhancing those associated with carbohydrate metabolism. Employing the culturomics methodology, 896 strains from 78 species (including 8 novel species) were isolated, resulting in a 10.1% isolation rate relative to the rumen bacterial community. Among them, 35 strains demonstrated boosted cellulose-degrading capability on plates, while 25 exhibited the ability to degrade hemicellulose as well. SynComs of these candidates were prepared based on the ratio observed in rumen microbiota exhibiting high cellulolytic performance. SynCom&#xa0;3 improved the neutral detergent fiber degradation (NDFD) by 20.39%&#xa0;averagely. Additionally, both in vitro and in situ assessments indicated that the optimization of dose/strain in SynCom&#xa0;3 significantly improved the in vitro NDFD by 20.56% and increased the in situ NDFD by 7.81%, along with the acidic detergent fiber (ADF,&#xa0;+&#x2009;11.47%). Genomic analysis revealed that the SynCom&#xa0;3 functioned well in fiber degradation through the synergistic action of key carbohydrate-active enzymes. CONCLUSIONS: This study strengthens rumen microbiome research by integrating omics and SynCom engineering within a microbiota-bacteria-enzymes-genes framework, revealing the significance of enzymatic synergy in carbohydrate metabolism. The findings establish a framework for utilizing low-abundance microbes and engineering functional consortia, which are crucial for improving ruminant feed utilization and biomass conversion. Future research should investigate the transcriptomic profiles and the metabolic cross-feeding mechanisms of fiber-degrading strains in the rumen. Video Abstract.

Animals

[Structure in rations of dairy cattle (author's transl)].

Efficient utilization of feed by ruminants is closely related to fermentation in the reticulum and rumen. A deficiency is long roughage ("structural material") may impair this fermentation and result in a low-milk fat syndrome. The deficiency in long roughage is particularly apparent in diets containing large amounts of readily available carbohydrates. Factors involved in the absence of structure were described. Readily available carbohydrates such as sugars and starch from grains will promote high concentrations of volatile fatty acids in the rumen. Chewing and ruminating stimulate the secretion of salive and so increase the buffering capacity of the rumen fluid. tlong roughage is required to maintain the structural layer in the rumen, inducing regular and rigorous contractions. The buffering capacity in conjunction with adequate rumen motility may partly reduce the effect of high concentrations of volatile fatty acids produced from high amounts of readily available carbohydrates. Coarseness and type of roughage also are important factors. At least one-third of the total uptake of dry matter should consist in long, coarse and fibrous roughage. Extremely high concentrations of volatile fatty acids in the rumen of high-yielding cows may be reduced to some extent by providing the mixture of concentrates in more meals a day at intervals of at least 3-4 hours.

Animal Feed