Multi‑omics reveals that the host‑microbiome metabolism crosstalk of differential rumen bacterial enterotypes can regulate the milk protein synthesis of dairy cows

Background Dairy cows’lactation performance is the outcome of the crosstalk between ruminal microbial metabo-lism and host metabolism.However,it is still unclear to what extent the rumen microbiome and its metabolites,as well as the host metabolism,contribute to regulating the milk protein yield(MPY).Methods The rumen fluid,serum and milk of 12 Holstein cows with the same diet(45%coarseness ratio),parity(2–3 fetuses)and lactation days(120–150 d)were used for the microbiome and metabolome analysis.Rumen metabolism(rumen metabolome)and host metabolism(blood and milk metabolome)were connected using a weighted gene co-expression network(WGCNA)and the structural equation model(SEM)analyses.Results Two different ruminal enterotypes,with abundant Prevotella and Ruminococcus,were identified as type1 and type2.Of these,a higher MPY was found in cows with ruminal type2.Interestingly,[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae(the differential bacteria)were the hub genera of the network.In addition,differential ruminal,serum and milk metabolome between enterotypes were identified,where the cows with type2 had higher L-tyrosine of rumen,ornithine and L-tryptophan of serum,and tetrahydroneopterin,palmitoyl-L-carnitine,S-lactoylglutathione of milk,which could provide more energy and substrate for MPY.Further,based on the identi-fied modules of ruminal microbiome,as well as ruminal serum and milk metabolome using WGCNA,the SEM analysis indicated that the key ruminal microbial module1,which contains the hub genera of the network([Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae)and high abundance of bacteria(Prevotella and Ruminococcus),could regulate the MPY by module7 of rumen,module2 of blood,and module7 of milk,which contained L-tyrosine and L-tryptophan.Therefore,in order to more clearly reveal the process of rumen bacterial regulation of MPY,we established the path of SEM based on the L-tyrosine,L-tryptophan and related components.The SEM based on the metabolites suggested that[Ruminococcus]gauvreauii group could inhibit the energy supply of serum tryptophan to MPY by milk S-lactoylglutathione,which could enhance pyruvate metabolism.Norank_f_Ruminococcaceae could increase the ruminal L-tyrosine,which could provide the substrate for MPY.Conclusion Our results indicated that the represented enterotype genera of Prevotella and Ruminococcus,and the hub genera of[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae could regulate milk protein synthesis by affecting the ruminal L-tyrosine and L-tryptophan.Moreover,the combined analysis of enterotype,WGCNA and SEM could be used to connect rumen microbial metabolism with host metabolism,which provides a fundamental understanding of the crosstalk between host and microorganisms in regulating the synthesis of milk composition.

Very early onset perinatal constipation:Can it be cow’s milk protein allergy?

Delayed passage of meconium or constipation during the perinatal period is traditionally regarded as a signal to initiate further work up to evaluate for serious diagnoses such as Hirschsprung’s disease(HD),meconium ileus due to Cystic Fibrosis,etc.The diagnosis of HD particularly warrants invasive testing to confirm the diagnosis,such as anorectal manometry or rectal suction biopsy.What if there was another etiology of perinatal constipation,that is far lesser known?Cow’s milk protein allergy(CMPA)is often diagnosed in infants within the first few weeks of life,however,there are studies that show that the CMPA allergen can be passed from mother to an infant in-utero,therefore allowing symptoms to show as early as day one of life.The presentation is more atypical,with perinatal constipation rather than with bloody stools,diarrhea,and vomiting.The diagnosis and management would be avoidance of cow's milk protein within the diet,with results and symptom improvement in patients immediately.Therefore,we discuss whether an alternative pathway to address perinatal constipation should be further discussed and implemented to potentially avoid invasive techniques in patients.This entails first ruling out CMPA with safe,noninvasive techniques with diet modification,and if unsuccessful,then moving forward with further diagnostic modalities.

The market for amino acids: understanding supply and demand of substrate for more efficient milk protein synthesis

For dairy production systems, nitrogen is an expensive nutrient and potentially harmful waste product. With three quarters of fed nitrogen ending up in the manure, significant research efforts have focused on understanding and mitigating lactating dairy cows' nitrogen losses. Recent changes proposed to the Nutrient Requirement System for Dairy Cattle in the US include variable efficiencies of absorbed essential AA for milk protein production. This first separation from a purely substrate-based system, standing on the old limiting AA theory, recognizes the ability of the cow to alter the metabolism of AA. In this review we summarize a compelling amount of evidence suggesting that AA requirements for milk protein synthesis are based on a demand-driven system. Milk protein synthesis is governed at mammary level by a set of transduction pathways, including the mechanistic target of rapamycin complex 1(mTORC1), the integrated stress response(ISR), and the unfolded protein response(UPR). In tight coordination, these pathways not only control the rate of milk protein synthesis, setting the demand for AA, but also manipulate cellular AA transport and even blood flow to the mammary glands, securing the supply of those needed nutrients. These transduction pathways, specifically mTORC1, sense specific AA, as well as other physiological signals, including insulin, the canonical indicator of energy status. Insulin plays a key role on mTORC1 signaling, controlling its activation, once AA have determined mTORC1 localization to the lysosomal membrane.Based on this molecular model, AA and insulin signals need to be tightly coordinated to maximize milk protein synthesis rate. The evidence in lactating dairy cows supports this model, in which insulin and glucogenic energy potentiate the effect of AA on milk protein synthesis. Incorporating the effect of specific signaling AA and the differential role of energy sources on utilization of absorbed AA for milk protein synthesis seems like the evident following step in nutrient requirement systems to further improve N efficiency in lactating dairy cow rations.

Genetic Polymorphism of Milk Protein and Their Relationships with Milking Performances in Chinese Yak

The milk protein polymorphisms were typed by polyacrylamide gel electrophoresis (PAGE)from 109 Maiwa and 100 Jiulong yaks, and the relationships among milk protein polymorphisms,milking traits and milk protein compositions were studied. The results showed thatβ-CN,κ-CN andα-La were monomorphic,αs1-CN andβ-Lg were polymorphic, the dominantgenes were αs1-CN D and β-Lg E,respectively. The frequencies of αs1-CN D were 0.8073and 0.6000 and β-Lg E were 0.9770 and 0.9700 in two populations respectively.The meanheterozygosities were 0.1021 and 0.1867 in two populations. No significant effects onmilking traits and milk protein compositions were observed except for αs1-CN locus onfat percentage in Jiulong yak.

Dietetic Valorization of Cow＇s Milk Proteins Fermented at 45 ℃ by Lactobacillus acidophilus Associated with Bifidobacteria

Cow＇s milk constitutes a significant food for babies when mother＇s milk is insufficient. The purpose of this work is to offer a fermented milk, potentially hypoallergenic, using selected Lactobaeillus acidophilus and Bifidobacteria sp. for their proteolytic activities. The fermentation is evaluated by the rate of lactic acid production and by the bacterial enumeration at 45 ℃. The rate of acidification obtained by mixed cultures （La ＋ B. longum, 63.8 ± 3.5 °D） and （La ＋ B. breve, 43.4 ± 1.67 °D） compared with the control （milk） （18.6 ± 1.31 °D）. The result of the best hydrolysis was obtained by （La＋ B. longum） （154.88 ± 30.33 ug/mg） which corresponded to a better release of the a-NH2 functions （103.32 ± 12.81 umoles/mg） compared with control （307.2 ± 11.54 ug/mg and 10.25 ± 0.44 umoles/mg ）. The best synergy was obtained by （La ＋ B. bifidum） （13 × 10^6 cfu/mL and 60 × 10^6 cfu/mL） and reached 95 × 10^10 cfu/mL and 119 × 10^10 cfu/mg at the end. The electrophoresis of fermented milk revealed the presence of soluble proteins （a-Lactalbumin and β-Lactoglobulin）. The Enzyme Linked Immtmo Sorbent Assay showed the results of residual antigenic activities of β-Lg （1.4 ± 0.23 ug/mg）, a-La （0.012 ± 0.004 ug/mg） and bovin serum albumin （0.014 ± 0.005 ug/mg）by the associations （La ＋ B. longum）, （La ＋ B. bifidum） and （La ＋ B. bifidum） compared with the control （14.43 ± 5.91 ug/mg, 0.183 ± 0.062 gg/mg, 0.05 ± 0.008 ug/mg） respectively. Lactic fermentation reduced to a significant antigenic reactivity of principal whey milk proteins.

Feeding Protected Lysine and Methionine Modifies Milk Protein Profile in Grazing Dairy Cows

The experiment was designed to determine the effect of protected lysine (Lys) and methionine (Met) supply on milk protein profile in grazing dairy cows specifically in the caseins (CNs) and α-lactalbumin fractions. Twelve multiparous mid lactation Holstein cows producing 24 (±4.76) kg of milk were assigned to one of two treatments (six cows per treatment) during an experimental period of 21 days. In the control (C) group, cows grazed a Pennisetum clandestinum pasture and were supplemented with a commercial concentrate according to milk production. In the Met-Lys treatment, cows received the same ration supplemented with protected Lys and Met. Milk yield and composition and milk protein profile were measured at the start and the end (21st day) of the experimental period. The Tricine-SDS-PAGE and the Gel-Quant Express Analysis (Invitrogen) software were used to determine milk protein composition. Statistical analysis was performed using the SAS’s PROC MIXED procedure through a mixed model that included the animal as a random effect and the treatments as a fixed effect adjusted by covariables. Milk production averaged 23.7 (±2.0) kg cow-1 day-1 without differences between treatments (P P -1 day-1) compared to C (24.2 kg cow-1 day-1). Milk protein content (g/kg) did not differ (C = 30.4;Met-Lys = 31.1) and lactose content tended (P P β-CN also increased (P < 0.05) after protected aminoacid supply (C = 9.58;Met-Lys = 10.35). It can be concluded that milk protein composition was improved by protected Lys-Met supply without altering other compositional parameters of milk composition. Milk nutritional quality and its potential yield for cheese-making were positively enhanced.

Changes in milk fat globule membrane proteins along lactation stage of Laoshan dairy goat

The milk fat globule membrane(MFGM)is a complex structure with numerous functions,and its composition is affected by many factors.There have been few systematic investigations on goat MFGM proteome profiling during lactation.Individual milk samples from 15 healthy dairy goats were obtained at six lactation time points for investigation of the MFGM proteome using both data-independent acquisition(DIA)and data-dependent acquisition(DDA)proteomics techniques combined with multivariate statistical analysis.Using the DIA method,890 variably abundant MFGM proteins were discovered throughout the lactation cycle.From 1 to 240 d,butyrophilin subfamily 1 member A1,lipoprotein lipase,perilipin-2,and adipose triglyceride lipase were upregulated,while APOE,complement C3,clusterin,and IgG were downregulated.Furthermore,from 1 to 90 d,annexin A1,annexin A2,and antithrombin-ll were downregulated,then upregulated by d 240.Albumin had a high degree of connectedness,indicating that it was a key protein,according to protein-protein interaction research.Overall,our findings gave new insights into the biological features of MFGM protein in goat milk throughout lactation,which may aid in the creation of specialized MFGM products and infant formula.

Milk protein concentrate and reduced-calcium milk protein concentrate as natural emulsifiers in clean label high-protein ice cream manufacture

Clean label food is a rising consumer trend in the food industry.Milk protein concentrate(MPC)and reduced-calcium milk protein concentrate(RCMPC)could serve as natural emulsifiers and increase the total protein content of ice cream products.The objectives of this study were to determine and compare the effects of MPC and RCMPC on ice cream composition,mix viscosity,storage stability,meltdown rate,and texture.A base formulation with 3%non-fat dry milk(NFDM)and no added emulsifiers was set as the control.Three levels of MPC or RCMPC(each powder containing 85%protein)at 1%,2%,and 3%were incorporated by replacing equivalent amounts of NFDM and keeping other ingredients unchanged.All ice cream treatments were processed with a target overrun of 70%and hardened at−25℃in a blast freezer.Additions of MPC or RCMPC at 1%,2%,and 3%corresponded to increases in protein content of ice cream by 15%,30%,and 45%,respectively.The viscosity of the ice-cream mix increased with increasing levels of MPC or RCMPC.In general,higher protein samples had slower meltdown rate and higher values of hardness and adhesiveness,but the trends were inconsistent.No shrinkage in volume was observed in any ice cream stored at−25℃after 180 days.However,an additional storage stability study revealed that the control showed significant shrinkage after 60 days(−6.5%±1.5%),90 days(−7.1%±1.8%),and 180 days(−7.9%±1.1%)in a typical household-style freezer at−13℃.MPC at 1%also showed significant shrinkage after 180 days,while samples with RCMPC at any levels showed no shrinkage at all.Ice cream manufacturers may consider MPC and RCMPC natural alternatives to synthetic emulsifiers,with RCMPC being more effective than MPC in terms of ice cream storage stability.

Potential antioxidant bioactive peptides from camel milk proteins

Camel milk is traditionally considered to have medicinal characteristics that it has potential health benefits and could help to treat several illnesses. Particularly, it is closest to human breast milk and has high levels of nutrients and bioactive components. The aim of this study was to explore the antioxidant peptides derived from protein fractions of camel milk. Camel milk proteins(CMP) were fractionated into camel casein protein(CCP) and camel whey protein(CWP), which were hydrolyzed with pepsin to produce peptic digests P-CCP and P-CWP, respectively. RP-HPLC was used for fractionation of the peptides from the P-CCP and P-CWP. The antioxidant activities were evaluated using superoxide anion generating system of xanthine oxidase(XOD)and 2,2-diphenyl-1-picrylhydrazyl(DPPH) scavenging assay. Active peptides were analyzed using matrixassisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF-MS) whereas a number of antioxidant peptides, with masses ranging from 913 to 2,951 Da, derived mainly from alpha-casein, lactophorin and lactoferrin, were identified. When yeast cells are used as a system for modeling mitochondrial disease, the peptides in caseins and whey fractions significantly enhanced the tolerance of yeast cells against peroxide-induced oxidative stress. The results show that both caseins and whey proteins of camel milk possess bioactive peptides with significant radical-scavenging activities and thus herald a fascinating opportunity for their potential as nutraceuticals or therapeutic peptides for prevention and treatment of oxidative stress-associated diseases.

Consensus statement on the epidemiology,diagnosis,prevention,and management of cow's milk protein allergy in the Middle East:a modified Delphi-based study

Background This study aimed to develop an expert consensus regarding the epidemiology,diagnosis,and management of cow’s milk protein allergy(CMPA)in the Middle East.Methods A three-step modified Delphi method was utilized to develop the consensus.Fifteen specialized pediatricians participated in the development of this consensus.Each statement was considered a consensus if it achieved an agreement level of>80%.Results The experts agreed that the double-blind placebo-controlled oral challenge test(OCT)should be performed for 2-A weeks using an amino acid formula(AAF)in formula-fed infants or children with suspected CMPA.Formula-fed infants with confirmed CMPA should be offered a therapeutic formula.The panel stated that an extensively hydrolyzed formula(eHF)is indicated in the absence of red flag signs.At the same time,the AAF is offered for infants with red flag signs,such as severe anaphylactic reactions.The panel agreed that infants on an eHF with resolved symptoms within 2-4 weeks should continue the eHF with particular attention to the growth and nutritional status.On the other hand,an AAF should be considered for infants with persistent symptoms;the AAF should be continued if the symptoms resolve within 2-4 weeks,with particular attention to the growth and nutritional status.In cases with no symptomatic improvements after the introduction of an AAF.other measures should be followed.The panel developed a management algorithm,which achieved an agreement level of 90.9%.Conclusion This consensus document combined the best available evidence and clinical experience to optimize the management of CMPA in the Middle East.

Current status of fecal calprotectin as a diagnostic or monitoring biomarker for cow's milk protein allergy in children:a scoping review

Background There are few approved biomarkers for diagnosis and monitoring of cow's milk protein allergy(CMPA),thus the oral food challenge remains to be the golden diagnostic standard.A potential biomarker is fecal calprotectin,a cytosolic protein,elevating in the presence of intestinal mucosal inflammation.We aimed to undertake a scoping review of the evi-dence pertaining to the current status of fecal calprotectin used for diagnosis and monitoring CMPA in children,and tried to indicate the aspects needed to be concerned in the future investigations and researches.Methods A scoping review was performed using the literature searched from PUBMED,EMBASE,and Web of Science Databases until July 2019 on the studies about the application of fecal calprotectin as a biomarker of CMPA in children.Studies were examined according to the inclusion and exclusion criteria.Data were extracted,and a narrative synthesis was conducted to summarize and analyze.Results Thirteen studies with different study design embracing 1238 children were included.The age range was from infants to adolescents.Most children with CMPA presented gastrointestinal symptoms,among which hematochezia was most com-mon.Amount of data suggested that infants with CMPA represented elevated levels of fecal calprotectin,particularly with distinct significance in non-IgE-mediated CMPA groups.Decreases of fecal calprotectin after elimination diet were demon-strated in enrolled studies.However,no matter in the CMPA positive or negative groups,the changes of fecal calprotectin before or after challenge showed no significance.Contradictory results were generated from studies on the role of fecal calprotectin in predicting allergic disease.Conclusions Available evidence is not sufficient to confirm the utilization of fecal calprotectin both in diagnosis and moni-toring of CMPA and predicting for allergic disease.More clinical and bench researches with elaborate design should be conducted and the exact cut-off values of fecal calprotectin in different groups remain to be determined.

Analysis of influence of water temperature on milk powder proteins using MALDI-TOF MS

The influence of water temperature on protein composition in the reconstitution of milk powder was evaluated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS）. 11 ion peaks in the matrix-assisted laser desorption/ionization （MALDI） spectra were examined to study the alteration of relative quantities of milk proteins when water at different temperature was employed in the reconstitution of milk powder. A discrepancy factor Dij was implemented to represent the degree of milk proteins＇ denaturation. Data obtained indicated that Dij value increased with rising water temperature, and thermal damage to milk proteins became evidently when the water temperature exceeded 60℃. The results confirmed that nutrient loss occurred when milk proteins denatured in water at high temperatures.

Efficacy of fermented milk and whey proteins in Helicobacter pylori eradication:A review

Helicobacter pylori (H. pylori) eradication is considered a necessary step in the management of peptic ulcer disease, chronic gastritis, gastric adenocarcinoma and mucosa associated lymphoid tissue lymphoma. Standard triple therapy eradication regimens are inconvenient and achieve unpredictable and often poor results. Eradication rates are decreasing over time with increase in antibiotic resistance. Fermented milk and several of its component whey proteins have emerged as candidates for complementary therapy. In this context the current review seeks to summarize the current evidence available on their role in H. pylori eradication. Pertinent narrative/systematic reviews, clinical trials and laboratory studies on individual components including fermented milk, yogurt, whey proteins, lactoferrin, &#x003b1;-lactalbumin (&#x003b1;-LA), glycomacropeptide and immunoglobulin were comprehensively searched and retrieved from Medline, Embase, Scopus, Cochrane Controlled Trials Register and abstracts/proceedings of conferences up to May 2013. A preponderance of the evidence available on fermented milk-based probiotic preparations and bovine lactoferrin suggests a beneficial effect in Helicobacter eradication. Evidence for &#x003b1;-LA and immunoglobulins is promising while that for glycomacropeptide is preliminary and requires substantiation. The magnitude of the potential benefit documented so far is small and the precise clinical settings are ill defined. This restricts the potential use of this group as a complementary therapy in a nutraceutical setting hinging on better patient acceptability/compliance. Further work is necessary to identify the optimal substrate, fermentation process, dose and the ideal clinical setting (prevention/treatment, first line therapy/recurrence, symptomatic/asymptomatic, gastritis/ulcer diseases etc.). The potential of this group in high antibiotic resistance or treatment failure settings presents interesting possibilities and deserves further exploration.

Study on screening potential allergenic proteins from infant milk powders based on human mast cell membrane chromatography and histamine release assays

Cow's milk allergy is mainly observed in infants and young children. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems. Conventional diagnosis is based on positive allergy studies and evaluation of parameters including IgE and IgG1 levels, acute allergic skin response and anaphylactic shock reactions. We developed a cell membrane chromatographic(CMC)method based on human mast cells(HMC-1) for screening potential allergens in infant formula milk powders(IFMP). HMC-1 cell membranes were extracted and mixed with silica to prepare cell membrane chromatography columns(10 mm ? 2 mm i.d., 5 mm). Under the conditions of 0.2 mL/min flow rate and214 nm detection wavelength, human breast milk showed no retention. However, IFMP showed clear retention. The retained fractions were collected and analyzed through matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS). Four major milk proteins, i.e., α-casein, β-casein, α-lactalbumin, and β-lactoglobulin A, were identified. Furthermore, these proteins and β-lactoglobulin B showed clear retention on HMC-1/CMC columns. To test the degranulation effects of the five proteins, histamine and β-hexosaminidase release assays were carried out. All five proteins induced HMC-1 cells to release histamine and β-hexosaminidase. Also, we established a reversed phase liquid chromatographic(RPLC) method for the determination of the five proteins in IFMP and the results showed that 90% proteins in IFMP were α-casein and β-casein. We concluded that cow's milk proteins may be potential allergens and caseins cause more β-casein allergic risk than other proteins. This conclusion was consistent with other studies.

Physico-Chemical Properties of Milk Whey Protein Agglomerates for Use in Oral Nutritional Therapy

Agglomerates based on milk whey proteins and modified starch (MS) were developed for patients with dysphagia. Calcium caseinate (CaCas), whey protein isolate (WPI), concentrate (WPC) and hydrolysate (WPH) were used. The sources were agglomerated with the MS and an increase in the porosity and viscosity of the agglomerates were observed. In all the systems evaluated, the WPI agglomerate at a concentration of 112 g/L showed a viscosity between 2122 and 5110 cP, and the agglomerates of WPC and WPH between 1115?-?2880 cP and 2600 - 6651 cP, respectively. CaCas exhibited high values in water and milk of 3200 cP and 6651 cP, respectively, and low values of 640 cP in juice. In sensory tests, the 70% WPI: 30% MS juice obtained a score 6.97, an improvement in relation to the other agglomerates, but not differing (p = 0.681) from the commercial thickener, 6.91 (p = 0.380). Based on these results, the 70% WPI: 30% MS was suggested for use in the nutritional therapy of patients with dysphagia.

Bacillus subtilis Co-transfected with a Lysine-rich and a Methionine-rich Protein Gene and Its Effect on Cow Milk Production

The probiotic Bacillus subtilis （B. subtilis） was widely applied in animal production as feed additive. Lysine （Lys） and methionine （Met） were the two most important limiting amino acids in livestock animal feed. Raising Lys and Met contents in B. subtilis would provide better effects for animal production and save Lys and Met supplements. We still didn＇t know whether Lys- rich and Met-rich protein genes from plants could be transfected into B. subtilis and expressed at a high level so as to improve animal production, such as milk production as an additional diet. The Lys-rich protein gene （Cflr） and Met-rich 10 ku-δ Zein were cloned from pepper anther and maize endosperm, respectively. Then they were constructed into plasmids individually and successfully cotransfected into B. subtilis. Upon IPTG induction, mRNAs and protein expressions could be observed. Lys and Met contents in the fermentation broth were raised by 65.92% and 46.39%, respectively. After feeding 200 g and 400 g· cow^-1· d^-1, transgenic B. subtilis fermentation broth, the milk yield, milk protein and milk fat contents all significantly increased. The Lys-rich protein gene （Cflr） and Met-rich 10 ku-δ Zein were successfully transfected into B. subtilis. Contents of Lys and Met in the transgenic B. subalis obviously raised and the fermentation broth of the transgenic bacteria could effectively improve milk yield and quality.

孕期因素与婴儿牛奶蛋白过敏的关系

目的:初步探讨孕期因素与婴儿牛奶蛋白过敏的关系。方法:数据来自一项“中国儿童对牛奶蛋白过敏的遗传易感性研究”的子队列,包括2020年3月1日至12月31日在北京大学人民医院出生的婴儿,根据随访至1岁时有无牛奶蛋白过敏(cow’s milk protein allergy,CMPA),分为病例组(CMPA组)和对照组。回顾性收集婴儿及其母亲孕前和孕期的临床资料,分析孕期多因素与婴儿牛奶蛋白过敏的相关性。结果:共纳入278例婴儿,CMPA患儿52例,对照组226例;男性婴儿143例,女性婴儿135例,其中男性婴儿在CMPA组比例(69.2%)高于对照组(47.3%),差异有统计学意义(P=0.004);CMPA患儿和对照组在出生体质量、出生胎龄、低出生体重儿、早产、脐带绕颈、新生儿窒息分布上差异无统计学意义(P>0.05)。母亲孕期合并免疫性疾病、贫血者以及孕期存在抗生素暴露者在CMPA组比例均高于对照组,两组之间差异有统计学意义(P<0.05);其他妊娠期合并症,如子痫/子痫前期、慢性高血压/妊娠期高血压、糖尿病/妊娠期糖尿病、甲状腺疾病等在两组分布差异无统计学意义(P>0.05)。CMPA组与对照组孕期多项血常规指标总体分布差异无统计学意义(P>0.05)。多因素Logistic回归分析发现男性婴儿、母亲妊娠合并免疫性疾病、妊娠合并贫血以及孕期抗生素暴露是CMPA发生的独立危险因素。结论:男性婴儿、母亲妊娠合并免疫性疾病、妊娠合并贫血以及孕期抗生素暴露是CMPA发生的独立危险因素。

《新生儿牛奶蛋白过敏诊断与管理专家共识(2023)》要点解读

新生儿牛奶蛋白过敏(cow's milk protein allergy,CMPA)临床表现不典型,可导致多器官和系统受累,并且可能影响新生儿体格生长和中枢神经系统发育,造成机体功能障碍,还会增加其他家庭成员的焦虑和压力。由于缺乏特异性临床表现和诊断方法,新生儿CMPA的诊断和管理仍然是目前非常重要的临床挑战。为促进新生儿CMPA规范化诊治,由中华医学会儿科学分会新生儿学组、中华儿科杂志编辑委员会组织制定了《新生儿牛奶蛋白过敏诊断与管理专家共识(2023)》,该文对该共识新生儿CMPA饮食和营养管理部分重点内容进行介绍和解读。

热诱导乳蛋白变性机理的研究进展

热处理经常在乳制品加工过程中被应用,以确保产品的安全性和更长的货架期。加热过程会导致乳蛋白的结构改变并进一步损伤产品最终的营养、感官品质以及产品性能,例如出现聚集、表观黏度增加以及沉降等现象,还会导致热交换器表面结垢影响热交换系统效率。本综述通过探讨影响乳蛋白热诱导变性的因素,主要从乳成分、理化性质以及工艺过程等方面深入分析乳蛋白热诱导变性机理,并总结归纳了提高乳蛋白热稳定性的方法,旨在为乳基液体产品特别是高蛋白乳制品以及浓缩乳产品的开发提供理论依据。

Whey Protein-Carboxymethylcellulose Obtained by Complex Coacervation as an Ingredient in Probiotic Fermented Milk

Discharge of whey proteins is still a current practice by small cheese producers. The development of low-cost alternatives for recovery of these proteins is fundamental for small producers who cannot apply expensive techniques. The present study investigated the complex coacervation technique as a cheap technology to recover proteins from sweet whey using carboxymethylcellulose, and the coacervate used as an ingredient in the formulation of probiotic fermented milk. The nutritional properties of whey-carboxymethylcellulose coacervates (WP-CMC) were evaluated in trials with animals (rats) using casein as a reference. All these parameters—the coefficient of feed efficiency (CEA), protein digestibility-corrected amino acid score (PDCAAS), and net protein ratio (NPR), as well as weight gain—were determined to evaluate protein quality. A sensory acceptance test was applied to evaluate the sensory characteristics of the product. The complex coacervation technique recovered 86% of the protein from sweet whey. No significant (p > 0.05) differences were observed in the biological tests for both groups (WP-CMC and Casein groups) when NPR (4.98 to 5.04), digestibility (92.35 to 90.64), and CEA (0.40 to 0.42) were evaluated. Probiotic fermented milk beverage containing WP-CMC (0.78%) and guar gum (0.68%) presented good acceptability as determined by sensory evaluation. WP-CMC can be considered an ingredient with high nutritional and biological value that could be applied in probiotic fermented milk as an alternative to small producers to allocate the residual whey from cheese manufacture.