Gastric digestion of cow and goat milk: Impact of infant and young child in vitro digestion conditions

BDH1 identified by transcriptome has a negative effect on lipid metabolism in mammary epithelial cells of dairy goats

BACKGROUND

The 3-hydroxybutyrate dehydrogenase 1 (BDH1) mainly participates in the regulation of milk fat synthesis and ketone body synthesis in mammary epithelial cells. In our previous study, BDH1 was identified as a key candidate gene regulating lipid metabolism in mammary glands of dairy goats by RNA-seq. This study aimed to investigate the effect of BDH1 on lipid metabolism in mammary epithelial cells of dairy goats (GMECs).

RESULTS

The results suggest that BDH1 plays a significant role in reducing triacylglycerol content and lipid droplet accumulation in GMECs (p < 0.05). Overexpression of BDH1 significantly decreased the expression of lipid metabolism-related genes (SREBF1 and GPAM) and reduced the levels of C14:0 and C17:1, while increasing FABP3 expression and C10:0 concentration (p < 0.05). Interference with BDH1 significantly increased the expression of SREBF1 and GPAM and the concentration of C14:0, C15:1, and C20:1, but significantly decreased FABP3 and C18:0 (p < 0.05). Treatment of GMECs with β-hydroxybutyric acid (R-BHBA) significantly decreased the expression of FASN, ACACA, LPL, SREBF1, FABP3, ACSL1, GPAM, DGAT1, and triacylglycerol content, while significantly increasing the expression of BDH1 (p < 0.05). Interference with BDH1 rescued the reduction of cellular TAG content and the expression of FASN, LPL, SREBF1, ACSL1, and GPAM in BHBA-treated GMECs.

CONCLUSION

In conclusion, BDH1 negatively regulates lipid metabolism in mammary glands of dairy goats. Furthermore, it may mitigate the inhibitory effect of R-BHBA on lipid metabolism in GMECs.

Investigating the effect of whey and casein proteins on drug solubility from a paediatric drug absorption perspective

Considering the predominantly milk-based diet of neonates and infants and their immature gastrointestinal digestion, milk proteins may affect drug behaviour and absorption in this population. Using in vitro models, this study investigated the impact of the representative milk proteins, whey and casein, on the solubility and permeation of the lipophilic model drugs spironolactone, clopidogrel and ritonavir. Drug solubility experiments revealed that the presence of milk proteins increased drug solubility. Next, permeation studies demonstrated that the same milk proteins reduced drug permeation across an artificial membrane. These results highlight the importance of the solubility-permeability interplay and indicate the effect of these proteins may be considered during (paediatric) drug development. Lastly, the findings underscore the importance of considering milk protein-drug interactions to optimize drug delivery strategies during (paediatric) drug development and especially for the youngest and most vulnerable part of this population.

Common gastrointestinal symptoms in healthy infants receiving goat milk-based formula or cow's milk-based formula: a double-blind, randomized, controlled trial

OBJECTIVE

To assess common gastrointestinal symptoms in healthy Brazilian infants receiving goat milk-based formula (GMF) compared to cow's milk-based formula (CMF).

METHODS

We performed a 24-weeks double-blind, randomized, controlled study in Brazil, enrolling healthy infants from 3 to 12 months of age. Primary outcome were the gastrointestinal (GI) symptoms stool consistency, regurgitation frequency and crying duration. Secondary outcomes were growth trajectories and hemoglobin levels. Repeated mixed models were used to compare outcomes variables between GMF and CMF groups, while adjusting for age at baseline.

RESULTS

Fifty-six infants were recruited and randomly allocated in the GMF (n = 26) and the CMF (n = 30) group. Scores on all measured GI symptoms were low and similar among the groups throughout intervention period and improved over time. Average age- and sex-adjusted WHO z-scores of weight, length, head circumference, and weight-for-length were all within +/-1 SD and similar between groups, indicating adequate growth. Serum hemoglobin was 11.1 (SD 0.7) g/dL in infants fed GMF and 11.0 (SD 0.8) g/dL in infants fed CMF after the intervention and was similar between groups.

CONCLUSION

GMF was well tolerated, safe and supported adequate growth in infants. This was shown by the low occurrence of GI symptoms, adequate blood hemoglobin levels and adequate growth within WHO standards.

TRIAL REGISTRATION

The clinical trial was approved by the ethics committee of the Federal University of Bahia under number CAAE06923319.5.0000.5577. The study was retrospectively registered in clinicaltrials.gov on 02/05/2024 under identifier NCT06395571.

A novel multiple plant-based milk alternative containing various preprocessed grains achieves better performance in protein digestibility and free amino acid profile via in vitro gastrointestinal digestion analysis

Plant-based milk alternatives are sustainable, hypoallergenic, and nutrient-rich, but challenges related to their lower bioavailability compared with animal-based milk still exist. In this study, we developed a multiple plant-based milk alternative using germinated soybeans and fermented cereals, and compared the protein digestible behaviors with commercial soy and bovine milk via in vitro gastrointestinal digestion. The multiple plant-based milk alternative possessed a higher level of essential amino acids and amino acid scores than the soy milk and a smaller percentage of low-molecular-weight peptides than the bovine milk. It displayed better protein-digestible responses with no apparent gastric coagulation. Moreover, the relatively larger particles in the multiple plant-based milk alternative had few effects on protein digestibility, with the highest proteolytic degree and a better free amino acid profile. The findings suggest that the multiple plant-based milk alternative presents higher protein digestibility behavior, and it could be a promising industrial plant-based product.

Functional attributes of bioactive peptides of bovine milk origin and application of in silico approaches for peptide prediction and functional annotations

Bovine milk peptides are the protein fragments with diverse bioactive properties having antioxidant, anticarcinogenic, other therapeutic and nutraceutical potentials. These peptides are formed in milk by enzymatic hydrolysis, gastrointestinal digestion and fermentation processes. They have significant health impact with high potency and low toxicity making them a suitable natural alternative for preventing and managing diseases. Antibiotic resistance has increased the quest for better peptide candidates with antimicrobial effects. This article presents a comprehensive review on well documented antimicrobial, immunological, opioid, and anti-hypertensive activities of bovine milk peptides. It also covers the usage of computational biology tools and databases for prediction and analysis of the food-derived bioactive peptides. In silico analysis of amino acid sequences of Bos taurus milk proteins have been predicted to generate peptides with dipeptidyl peptidase IV inhibitory and ACE inhibitory properties, making them favorable candidates for developing blood sugar lowering drugs and anti-hypertensives. In addition to the prediction of new bioactive peptides, application of bioinformatics tools to predict novel functions of already known peptides is also discussed. Overall, this review focuses on the reported as well as predicted biologically active peptide of casein and whey proteins of bovine milk that can be utilized to develop therapeutic agents.

Glycation of goat milk with different casein-to-whey protein ratios and its effects on simulated infant digestion

This research compared the effects of dry heating on the digestion of goat milk proteins with different casein-to-whey ratios (40% casein, C40 and 80% casein, C80). The glycation markers of heated samples were determined by LC-MS. Heating at 60 °C for 8 h induced early glycation while heating at 60 °C for 72 h induced advanced glycation. Unheated C80 samples showed a higher digestibility than unheated C40 samples, which may be due to their higher protein solubility. After dry heating for 72 h, no significant difference in digestibility was observed between C80 and C40 samples. Heating for 72 h decreased the digestibility of C40 samples compared to unheated samples, probably due to glycation, while protein aggregation was the main reason for the reduced digestibility of heated C80 samples. Overall, this study showed that dry heating for 72 h induced a lower digestibility of C80 and C40 samples, although with different underlying mechanisms.

Goat Milk Allergy and a Potential Role for Goat Milk in Cow's Milk Allergy

In many parts of the world, goat milk has been part of the human diet for millennia. Allergy to goat's milk, not associated with allergy to cow's milk, is a rare disorder, although some cases have been described. Goat milk proteins have substantial homology with cow's milk proteins and even show cross-reactivity; therefore, they are not advised as an alternative to cow's milk for infants with IgE-mediated cow's milk allergies. However, there are indications that, due to the composition of the goat milk proteins, goat milk proteins show lower allergenicity than cow's milk due to a lower αS1-casein content. For this reason, goat milk might be a better choice over cow's milk as a first source of protein when breastfeeding is not possible or after the breastfeeding period. Additionally, some studies show that goat milk could play a role in specific types of non-IgE-mediated cow milk allergy or even in the prevention of sensitization to cow's milk proteins. This review discusses a possible role of goat milk in non-IgE mediated allergy and the prevention or oral tolerance induction of milk allergy.

Delivery of encapsulated bioactive compounds within food matrices to the digestive tract: recent trends and future perspectives

Encapsulation technologies have achieved encouraging results improving the stability, bioaccessibility and absorption of bioactive compounds post-consumption. There is a bulk of published research on the gastrointestinal behavior of encapsulated bioactive food materials alone using in vitro and in vivo digestion models, but an aspect often overlooked is the impact of the food structure, which is much more complex to unravel and still not well understood. This review focuses on discussing the recent findings in the application of encapsulated bioactive components in fabricated food matrices. Studies have suggested that the integration of encapsulated bioactive compounds has been proven to have an impact on the physicochemical characteristics of the finished product in addition to the protective effect of encapsulation on the fortified bioactive compound. These products containing bioactive compounds undergo further structural reorganization during digestion, impacting the release and emptying rates of fortified bioactive compounds. Thus, by manipulation of various food structures and matrices, the release and delivery of these bioactive compounds can be altered. This knowledge provides new opportunities for designing specialized foods for specific populations.

Dynamic Gastrointestinal Digestion of Bovine, Caprine and Ovine Milk Reconstituted from Commercial Whole Milk Powders

The global dairy market has been increasingly diversified with more dairy product offerings of milk products from different animal species. Meanwhile, milk powders remain the main exported dairy product format due to their ease of transportation. In this work, we studied the structural changes, protein hydrolysis and nutrient delivery during dynamic gastric digestion and small intestinal digestion of cow, goat and sheep milk reconstituted from commercial whole milk powders. The results show that the reconstituted milks digest similarly to processed fresh milk. The digestion behaviors of the three reconstituted ruminant milks are broadly similar (gastric coagulation, kinetics of gastric emptying of protein and fat and the high digestibility in the small intestine) with some differences, which are likely contributed by the processing history of the milk powders. The delivery of individual amino acids to the small intestine differed between the early and late stages of gastric digestion, which were primarily affected by the abundance of amino acids in caseins and whey proteins but also by the difference between milk types associated with their gastric coagulation behaviors. This work showed that powdered milk is similar to fresh processed milk in digestion behavior, and the inherent differences between ruminant milks can be modified by processing treatments.

Dynamic In Vitro Gastric Digestion Behaviour of Commercial Infant Formulae Made with Cow, Goat and Sheep Milk

There are a wide range of commercial infant formulae available on the market. These are made using milk from different species, such as goat, sheep, and cow. The different protein compositions of these milks and the process used during infant-formulae manufacture, such as heat treatment, may impact the digestion of nutrients. This study compared the effect of protein composition and heat treatment on the in vitro gastric digestion behaviour of commercial infant formulae made with cow, goat, and sheep milk using a dynamic infant human gastric simulator (IHGS). During the simulated dynamic gastric digestion, the goat milk infant formula (GIF) showed earlier signs of aggregate formation compared to cow milk infant formula (CIF) and sheep milk infant formula (SIF). In addition, the microstructures of GIF chyme showed fragmented and porous structures. On the contrary, CIF formed dense protein networks that trapped oil droplets, whereas SIF exhibited a microstructure of smooth oil droplets surrounded by fewer protein networks. The different aggregation behaviours and aggregate structures of the three infant-formulae chyme were related to their different protein compositions, especially the different casein compositions. Furthermore, the open fragile structure of GIF aggregates provided easier access to pepsin, allowing it to hydrolyse protein. The results from the present study provided some information to assist in understanding the coagulation and digestion behaviours of commercial infant formulae made from different species of milk.

Which is the optimal choice for neonates' formula or breast milk?

The incidence of prematurity has been increasing since the twenty-first century. Premature neonates are extremely vulnerable and require a rich supply of nutrients, including carbohydrates, proteins, docosahexaenoic acid (DHA), arachidonic acid (ARA) and others. Typical breast milk serves as the primary source for infants under six months old to provide these nutrients. However, depending on the individual needs of preterm infants, a more diverse and intricate range of nutrients may be necessary. This paper provides a comprehensive review of the current research progress on the physical and chemical properties, biological activity, function, and structure of breast milk, as well as explores the relationship between the main components of milk globular membrane and infant growth. Additionally, compare the nutritional composition of milk from different mammals and newborn milk powder, providing a comprehensive understanding of the differences in milk composition and detailed reference for meeting daily nutritional needs during lactation.

Effect of pH and protein composition on proteolysis of goat milk proteins by pepsin and pancreatin

The roles of protein composition, pH and enzymes in goat milk protein hydrolysis is still unclear and the proteolysis of low abundant goat milk proteins has received limited attention. The aim of this study was to study the impact of protein composition and proteolytic conditions on goat milk protein hydrolysis in a simplified digestion model. Both whole milk and infant formula were hydrolyzed at pH 2 and 4, using pepsin as well as pepsin combined with pancreatin. Intact proteins were separated from digests using spin filters, followed by bottom-up proteomics of the separated proteins. Results show that under all conditions, caseins are hydrolyzed quickly. Goat casein hydrolysis in infant formula was slightly faster than in goat whole milk, possibly due to less casein coagulation during pepsin hydrolysis at both pH 2 and 4. Several low abundant immunoactive goat milk proteins, especially immunoglobulins, GLYCAM-1 and osteopontin, resisted proteolysis more than high abundant proteins, independent of the pH and enzyme used for hydrolysis. Fast hydrolysis of casein and slow hydrolysis of immunoactive proteins may indicate a good balance between protein utilization and protection of the infant by goat milk proteins.

Comparative Analysis of Protein Digestion Characteristics in Human, Cow, Goat, Sheep, Mare, and Camel Milk under Simulated Infant Condition

An infant in vitro digestion model was utilized to investigate protein digestion characteristics in human and diverse mammalian milk (i.e., cow, goat, sheep, mare, and camel milk) using electrophoresis and chromatography. Digestive differences among milks were mainly manifested in the infant gastric phase, as evidenced by varying degrees of protein digestion. Notably, proteins (i.e., lactoferrin, serum albumin, and immunoglobulin G-heavy chain) remained partially intact in human milk, whereas these proteins in animal milk were exclusively degraded after gastrointestinal digestion. The peptide spectra of human, mare, and camel milk were highly similar, with a predominant formation of low-intensity small peptides, whereas the other three milk showed the opposite phenomenon. Heatmap cluster analysis indicated that camel milk was the most comparable to human milk before digestion, yet sheep milk was the most similar to human milk regarding protein digestion behaviors following infant gastric digestion.

Differences in small intestinal apparent amino acid digestibility of raw bovine, caprine, and ovine milk are explained by gastric amino acid retention in piglets as an infant model

Background

The rate of stomach emptying of milk from different ruminant species differs, suggesting that the small intestinal digestibility of nutrients could also differ across these milk types.

Objective

To determine the small intestinal amino acid (AA) digestibility of raw bovine, caprine, and ovine milk in the piglet as an animal model for the infant.

Methods

Seven-day-old piglets (n = 12) consumed either bovine, caprine, or ovine milk diets for 15 days (n = 4 piglets/milk). On day 15, fasted piglets received a single meal of fresh raw milk normalized for protein content and containing the indigestible marker titanium dioxide. Entire gastrointestinal tract contents were collected at 210 min postprandially. Apparent AA digestibility (disappearance) in different regions of the small intestine was determined.

Results

On average, 35% of the dietary AAs were apparently taken up in the small intestine during the first 210 min post-feeding, with 67% of the AA digestibility occurring in the first quarter (p ≤ 0.05) and 33% in the subsequent two quarters. Overall, except for isoleucine, valine, phenylalanine, and tyrosine, the small intestinal apparent digestibility of all AAs at 210 min postprandially in piglets fed ovine milk was, on average, 29% higher (p ≤ 0.05) than for those fed bovine milk. Except for lysine, there was no difference in the apparent digestibility (p > 0.05) of any AAs between piglets fed caprine milk or ovine milk. The apparent digestibility of alanine was higher (p ≤ 0.05) in piglets fed caprine milk than those fed bovine milk. When apparent digestibility was corrected for gastric AA retention, only small differences in the small intestinal apparent digestibility of AAs were observed across milk types.

Conclusion

Bovine, caprine and ovine milk had different apparent small intestinal AA digestibility at 210 min postprandially. When corrected for gastric AA retention, the differences in apparent digestibility across species largely disappeared. The apparent AA digestibility differed across small intestinal locations.

Gastrointestinal digestibility of micellar casein dispersions: Effects of caprine vs bovine origin, and partial colloidal calcium depletion using in vitro digestion models for the adults and elderly

In vitro coagulation and digestion of caprine and bovine micellar casein concentrate (MCC) with or without partial colloidal calcium depletion (deCa) were studied under simulated adult and elderly conditions. Gastric clots were smaller and looser for caprine than bovine MCC, and were further looser with deCa and under elderly condition for both caprine and bovine MCC. Casein hydrolysis and concomitant formation of large peptides was faster for caprine than bovine MCC, and with deCa and under adult condition for caprine and bovine MCC. Formation of free amino groups and small peptides were faster for caprine MCC, and with deCa and under adult condition. Upon intestinal digestion, proteolysis occurred rapidly, and was faster under adult condition, but showed less differences with increasing digestion between caprine and bovine MCC, and with and without deCa. These results suggested weakened coagulation and greater digestibility for caprine MCC and MCC with deCa under both conditions.

Impact of mixing coriander oil with goat feed on the chemical, microbiological and sensory characterizations of bio rayeb milk

This research aimed to investigate the properties of bio rayeb milk that results from goats fed on feed supplemented with different concentrations of coriander oil. The study design included a control treatment (C) and two coriander oil concentrations, a low level of (0.95%) T1 and a high level of (1.9%) T2. A probiotic starter culture, Direct Vat Set (DVS) of lactobacillus delbrueckii ssp. bulgaricus and streptococcus salivarius ssp. thermophilus in the ratio (1:1) was used to prepare bio rayeb. All treatments were stored at 4 °C for 2 weeks and analyzed on day one and at the end of storage. Results showed that the coagulation time during bio rayeb manufacturing remained consistent at almost 6 h for all batches. However, using a high coriander oil level (1.90%) significantly decreased the apparent viscosity and the content of monounsaturated fatty acids. The DPPH inhibition and the content of monounsaturated fatty acids increased. The electrophoresis chromatogram exhibited a high degree of proteolysis in T2 compared to the control and T1. Microbiologically, yeast, molds, and coliforms were absent in all treatments. Feeding goats on provender supplemented with a low concentration of coriander oil may positively impact the resultant milk's technological and sensorial properties.

Lactobacillus casei-Derived Postbiotics Elevate the Bioaccessibility of Proteins via Allosteric Regulation of Pepsin and Trypsin and Introduction of Endopeptidases

The potential of probiotics to benefit digestion has been widely reported, while its utilization in high-risk patients and potential adverse reactions have focused interest on postbiotics. A variable data-independent acquisition (vDIA)-based spatial-omics strategy integrated with unsupervised variational autoencoders was applied to profile the functional mechanism underlying the action of Lactobacillus casei-derived postbiotic supplementation in goat milk digestion in an infant digestive system, from a metabolomics-peptidomics-proteomics perspective. Amide and olefin derivatives were proved to elevate the activities of pepsin and trypsin through hydrogen bonding and hydrophobic forces based on allosteric effects, and recognition of nine endopeptidases and their cleavage to serine, proline, and aspartate were introduced by postbiotics, thereby promoting the generation of hydrophilic peptides and elevating the bioaccessibility of goat milk protein. The peptides originating from αs1-casein, β-casein, β-lactoglobulin, Ig-like domain-containing protein, κ-casein, and serum amyloid A protein, with multiple bioactivities including angiotensin I-converting enzyme (ACE)-inhibitory, osteoanabolic, dipeptidyl peptidase IV (DPP-IV) inhibitory, antimicrobial, bradykinin-potentiating, antioxidant, and anti-inflammatory activities, were significantly increased in the postbiotic supplementation group, which was also considered to potentially prevent necrotizing enterocolitis through inhibiting the multiplication of pathogenic bacteria and blocking signal transducer and activator of transcription 1 and nuclear factor kappa-light-chain-enhancer of activated B cells inflammatory pathways. This research deepened the understanding of the mechanism underlying the postbiotics affecting goat milk digestion, which established a critical groundwork for the clinical application of postbiotics in infant complementary foods.

Bioimprinted lipase-catalyzed synthesis of medium- and long-chain structured lipids rich in docosahexaenoic acid for infant formula

Medium- and long-chain structured lipids (MLSLs) rich in docosahexaenoic acid (DHA) were obtained in shorter reaction time by acidolysis of single-cell oil (DHASCO) from Schizochytrium sp. with caprylic acid (CA) using a lipase bioimprinted with fatty acids as a catalyst. The conditions for preparation of the bioimprinted lipase for the acidolysis reaction were firstly optimized and the activity of the obtained lipase was 2.17 times higher than that of the non-bioimprinted. The bioimprinted lipase was then used as a catalyst and the reaction conditions were optimized. Under the optimal conditions, the equilibrium could be achieved in 4 h, and the total and sn-1,3 CA contents in the product were 29.18% and 42.34%, respectively, and the total and sn-2 DHA contents were 46.26% and 70.12%, respectively. Such MLSLs rich in sn-1,3 CA and sn-2 DHA are beneficial for DHA absorption, and thus have potential for use in infant formula.

The protein dynamics of bovine and caprine β-lactoglobulin differ as a function of pH

The properties of milk proteins differ between mammalian species. β-Lactoglobulin (βlg) proteins from caprine and bovine milk are sequentially and structurally highly similar, yet their physicochemical properties differ, particularly in response to pH. To resolve this conundrum, we compared the dynamics of both the monomeric and dimeric states for each homologue at pH 6.9 and 7.5 using hydrogen/deuterium exchange experiments. At pH 7.5, the rate of exchange is similar across both homologues, but at pH 6.9 the dimeric states of the bovine βlg B variant homologue have significantly more conformational flexibility compared with caprine βlg. Molecular dynamics simulations provide a mechanistic rationale for the experimental observations, revealing that variant-specific substitutions encode different conformational ensembles with different dynamic properties consistent with the hydrogen/deuterium exchange experiments. Understanding the dynamic differences across βlg homologues is essential to understand the different responses of these milks to processing, human digestion, and differences in immunogenicity.

The Effect of Goat-Milk-Based Infant Formulas on Growth and Safety Parameters: A Systematic Review and Meta-Analysis

Goat-milk-based infant formulas (GMFs) are now available in several countries, having been approved by authorities. We systematically evaluated the effects of GMF compared with cow-milk-based formula (CMF) on infant growth and safety parameters. The MEDLINE, EMBASE, and Cochrane Library databases were searched (December 2022) for randomized controlled trials (RCTs). The risk of bias was assessed using the Revised Cochrane Risk-of-Bias tool (ROB-2). Heterogeneity was quantified by I². Four RCTs involving a total of 670 infants were identified. All trials revealed some concern in ROB-2. Furthermore, all of the included studies were funded by the industry. Compared with infants fed CMF, those fed GMF showed similar growth in sex- and age-adjusted z-scores for weight (mean difference, MD, 0.21 [95% confidence interval, CI, -0.16 to 0.58], I² = 56%), length (MD 0.02, [95% CI -0.29 to 0.33], I² = 24%), and head circumference (MD 0.12, 95% [CI -0.19 to 0.43], I² = 2%). Stool frequency was similar among the groups. Due to differences in the reporting of stool consistency, no firm conclusion can be drawn. Adverse effects (serious or any) were similar in both groups. These findings provide reassurance that GMFs compared with CMFs are safe and well tolerated.

Effects of infant feeding with goat milk formula or cow milk formula on atopic dermatitis: protocol of the randomised controlled Goat Infant Formula Feeding and Eczema (GIraFFE) trial

INTRODUCTION

Atopic dermatitis (AD) is a chronic, inflammatory skin condition significantly affecting quality of life. A small randomised trial showed an approximately one-third lower incidence of AD in goat milk formula-fed compared with cow milk formula-fed infants. However, due to limited statistical power, AD incidence difference was not found to be significant. This study aims to explore a potential risk reduction of AD by feeding a formula based on whole goat milk (as a source of protein and fat) compared with a formula based on cow milk proteins and vegetable oils.

METHODS AND ANALYSIS

This two-arm (1:1 allocation), parallel, randomised, double-blind, controlled nutritional trial shall enrol up to 2296 healthy term-born infants until 3 months of age, if parents choose to start formula feeding. Ten study centres in Spain and Poland are participating. Randomised infants receive investigational infant and follow-on formulas either based on whole goat milk or on cow milk until the age of 12 months. The goat milk formula has a whey:casein ratio of 20:80 and about 50% of the lipids are milk fat from whole goat milk, whereas the cow milk formula, used as control, has a whey:casein ratio of 60:40 and 100% of the lipids are from vegetable oils. The energy and nutrient levels in both goat and cow milk formulas are the same. The primary endpoint is the cumulative incidence of AD until the age of 12 months diagnosed by study personnel based on the UK Working Party Diagnostic Criteria. The secondary endpoints include reported AD diagnosis, measures of AD, blood and stool markers, child growth, sleep, nutrition and quality of life. Participating children are followed until the age of 5 years.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the ethical committees of all participating institutions.

TRIAL REGISTRATION NUMBER

NCT04599946.

Unlocking the bioactivity of meat proteins: Comparison of meat and meat hydrolysate via simulated gastrointestinal digestion

Understanding the functional attributes of meat proteins is crucial for determining their nutritional benefits. Depending on the form in which meat proteins are available, the digestive process can release peptides which are valuable for nutrition and may also possess bioactive properties, affecting physiology. Liquid chromatography - mass spectrometry (LC-MS) was used to quantitatively compare the molecular peptide features (representing non-redundant peptides), during the different stages of a simulated gastrointestinal digestion process of a minimally processed powdered meat and its enzymatically produced hydrolysate. Results from a principal component analysis (PCA) indicated that the hydrolysate did not undergo extensive additional digestion whereas the powdered meat was digested both at the gastric and in the intestinal phases. Bioactive peptide sequence prediction identified the meat hydrolysate but not the meat powder as the only source of exact and partial bioactive matches in the angiotensin-I converting enzyme and dipeptidyl peptidase IV inhibition categories. Also, a higher source of cryptides (encrypted bioactive peptides), indicated that meat hydrolysates are potentially a better substrate for the release of these enzyme inhibitory peptides. These observations thus suggest that pre-digestion of a complex food matrix such as meat, may enhance its bioavailability following oral consumption early in the digestion process. SIGNIFICANCE: This work highlights enzymatic hydrolysis of meat proteins prior to ingestion allows for potentially higher bioavailability of bioactive peptides that inhibit angiotensin-I converting enzyme and dipeptidyl peptidase IV, thus possibly aiding high blood pressure and type 2 diabetes management.

Calcium bioaccessibility increased during gastrointestinal digestion of α-lactalbumin and β-lactoglobulin

Calcium bioaccessibility depends on the amount of soluble calcium under intestinal digestion. The changes in calcium during in vitro static digestion of α-lactalbumin and β-lactoglobulin in presence of calcium chloride (0 mM, 20 mM and 50 mM) were followed by combining electrochemical determination of free calcium with the determination of soluble calcium by inductively coupled plasma optical emission spectroscopy. α-Lactalbumin and, more evident, β-lactoglobulin were found to increase calcium bioaccessibility with increasing intestinal digestion time by around 5% and 10%, respectively, due to the complex binding of calcium to peptides formed from protein hydrolysis by gastrointestinal enzymes. In vitro digested samples of β-lactoglobulin in presence of CaCl₂ had nearly twice as much complex bound calcium as α-lactalbumin samples. The calcium bioaccessibility decreased significantly with the increasing concentration of added calcium chloride, although the amount of calcium chloride had little effect on the extension of digestion of α-lactalbumin and β-lactoglobulin. Simulated digestion fluids were found to have a negative effect on calcium bioaccessibility, especially the presence of hydrogen phosphate, and the amount of precipitated calcium increased significantly with increasing amount of added calcium chloride. Based on analysis and visualization by sequences of the peptides formed during digestion of α-lactalbumin and β-lactoglobulin, it was observed that peptides containing aspartic acid and glutamic acid acting as calcium chelators, may prevent precipitation of calcium in the intestines and increase calcium bioaccessibility. These results provide knowledge for the design of new dairy based functional foods to prevent calcium deficiency.

Genome-wide analysis for the melatonin trait associated genes and SNPs in dairy goat (Capra hircus) as the molecular breeding markers

Previous studies have reported that the endogenous melatonin level is positively associated with the quality and yield of milk of cows. In the current study, a total of 34,921 SNPs involving 1,177 genes were identified in dairy goats by using the whole genome resequencing bulked segregant analysis (BSA) analysis. These SNPs have been used to match the melatonin levels of the dairy goats. Among them, 3 SNPs has been identified to significantly correlate with melatonin levels. These 3 SNPs include CC genotype 147316, GG genotype 147379 and CC genotype 1389193 which all locate in the exon regions of ASMT and MT2 genes. Dairy goats with these SNPs have approximately 5-fold-higher melatonin levels in milk and serum than the average melatonin level detected in the current goat population. If the melatonin level impacts the milk production in goats as in cows, the results strongly suggest that these 3 SNPs can serve as the molecular markers to select the goats having the improved milk quality and yield. This is a goal of our future study.

Saudi Traditional Fermented Goat Milk Protects against Experimental Non-Alcoholic Fatty Liver Disease by Hypoglycaemic and Antioxidant Potentials

This study examined the effect of fermented goat milk (oggtt) against non-alcoholic fatty liver disease (NAFLD) in rats induced by chronic high-fat diet (HFD) treatments. Both control-fed and HFD-fed adult male rats received the same vehicle or treatment with two doses of freshly collected oggtt (2 mL or 5 mL) for 12 weeks (n = 8/group). The treatment of the control and HFD-fed rats with oggtt in both doses significantly reduced weight gain, but fasting serum glucose and insulin levels as well as HOMA-IR levels were lowered only in the HFD-fed rats. Treatment improved HFD-induced glucose and insulin homeostasis impairment as measured by the oral glucose tolerance test. Both doses of oggtt reduced serum levels of liver function markers and C-reactive protein (CRP) as well as hepatic levels of malondialdehyde (MDA), tumour necrosis factor-α (TNF-α), and in-terlukin-6 (IL-6) in HFD-fed rats. In addition, the oggtt doses reduced serum and hepatic levels of triglycerides (TGs) and cholesterol (CHOL) as well as serum levels of low-density lipoproteins (LDL) in these rats. These biochemical endpoints were reflected by the improvement in liver histology and reduction in the number of fatty vacuolated and pyknotic cells. In both the control and HFD-fed rats, oggtt at both doses stimulated levels of superoxide dismutase (SOD) and glutathione (GSH). All these effects were more profound with the highest dose of oggtt. In conclusion, the finding of this study strongly supports the use of oggtt as a functional food to treat NAFLD, as it has shown hypoglycaemic and antioxidant properties.

Effects of In Vitro Digestion on Anti-α-Amylase and Cytotoxic Potentials of Sargassum spp

This is the first study to examine the effects of in vitro digestion on biological activities of Sargassum spp., a broadly known brown seaweed for therapeutic potential. Three fractions (F1-F3) were obtained from hexane extract by column chromatography. Under in vitro simulated digestion, the anti-α-amylase capacity of F1 in oral and intestinal phases increases, while it significantly decreases in the gastric phase. The α-amylase inhibition of F2 promotes throughout all digestive stages while the activity of F3 significantly reduces. The cytotoxic activity of F1 against U266 cell-line accelerates over the oral, gastric, and intestinal stages. The fractions F2 and F3 exhibited the declined cytotoxic potentialities in oral and gastric phases, but they were strengthened under intestinal condition. Palmitic acid and fucosterol may play an active role in antidiabetic and cytotoxic activity against multiple myeloma U266 cell line of Sargassum spp. However, the involvement of other phytochemicals in the seaweed should be further investigated.

Starch and protein hydrolysis in cooked quinoa (Chenopodium quinoa Willd.) during static and dynamic in vitro oral and gastric digestion

Quinoa is a pseudocereal that has a favorable nutrient profile and may be a beneficial addition to the diet. To evaluate potential health-promoting properties of foods, it is important to understand the rate of macronutrient hydrolysis, which is commonly quantified through in vitro digestion studies. Additionally, limited information is available comparing starch and protein hydrolysis of solid foods using static and dynamic digestion models. The objective of this study was to examine starch and protein hydrolysis in cooked quinoa using a combination of a static (saliva only) or dynamic (saliva + mincing) oral digestion model with a static (gastric fluids only) or dynamic (Human Gastric Simulator) gastric digestion model. Disruption of the pericarp of the cooked quinoa seeds during dynamic oral digestion released additional surface area, which led to faster gastric emptying during dynamic gastric digestion. Starch and protein hydrolysis were impacted by type of gastric model due to differences in pH and variations in structural breakdown. Starch hydrolysis was 29.04 ± 1.83% after 180 min dynamic gastric digestion compared to 2.85 ± 1.88% during static gastric digestion (averaged across both oral digestion models). The degree of protein hydrolysis was 4.85 ± 0.01% after 180 min in the static gastric model compared to 3.94 ± 0.18% in the dynamic gastric model (averaged across both oral digestion models). This information provides evidence on the role of food structure and breakdown (through use of static vs. dynamic oral and gastric digestion models) on quinoa starch and protein hydrolysis.

An evolving view on food viscosity regulating gastric emptying

Viscosity is a property of most foods. The consumption of the high-viscosity food is associated with a variety of physiological responses, one of which is their ability to regulate gastric emptying and modulate postprandial glycemic response. Gastric emptying has been proven to be a key step affecting the digestion and absorption of food, whereas, the relationship between viscosity and gastric emptying is still far away from being understood. Here, we reviewed the factors that influence food viscosity and food viscosity changes during digestion. Besides, the effect of food viscosity on gastric emptying and food-viscosity-physiological response were highlighted. Finally, "quantitative relationship" of viscosity and gastric emptying was discussed. This review can contribute to the understanding that how food viscosity affects gastric emptying, and help for developing foods that could control satiety and manage body weight for the specific populations.

Recent Insights Into Processing Approaches and Potential Health Benefits of Goat Milk and Its Products: A Review

Goat milk is considered to be a potential source of various macro- and micro-nutrients. It contains a good proportion of protein, fat, carbohydrates, and other nutritional components which help in promoting nutritional and desirable health benefits. Goat milk is considered to be superior in terms of numerous health benefits, and lower risk of allergy, when compared to the milk of other species. Several processing techniques such as pasteurization, ultrafiltration, microfiltration, and ultrasound have been employed to enhance the quality and shelf life of goat milk and its products. The diverse range of goat milk-based products such as yogurt, cheese, fermented milk, goat milk powder, and others are available in the market and are prepared by the intervention of advanced processing technologies. Goats raised in pasture-based feeding systems are shown to have a better milk nutritional composition than its counterpart. Goat milk contains potential bioactive components, which aids in the maintenance of the proper metabolism and functioning of the human body. This review gives insight into the key nutritional ingredients and bioactive constituents present in goat milk and their potential role in the development of various functional foods using different processing technologies. Goat milk could be considered as a significant option for milk consumption in infants, as compared to other milk available.

Compositional and Functional Considerations for Bovine-, Caprine- and Plant-Based Infant Formulas

Breastmilk is the optimal source of nutrition for infants. However, in circumstances where breastfeeding is not possible or feasible, infant formula provides an essential alternative to fulfil the nutritional requirements of the developing infant. Traditionally, the manufacture of infant formula has involved utilisation of bovine milk as a base ingredient, formulated with other nutrients and bioactive ingredients to closely match the composition of human breastmilk. While it is the most widely available type of formula on the market, bovine-based infant formula is not suitable for all infants, and therefore alternatives such as those based on caprine milk, soy and rice protein are becoming increasingly available. This review provides a detailed examination of the composition of infant formula prepared from bovine milk, caprine milk, soy, and rice protein sources. Available literature on nutrient bio-accessibility and aspects of protein functionality relevant to infant formula is discussed.

Digestibility of proteins in camel milk in comparison to bovine and human milk using an in vitro infant gastrointestinal digestion system

The absence of β-lactoglobulin, high β-/α_s-casein ratio and protective proteins make camel milk a promising alternative protein base for making human infant formulae. In this study, protein digestibility of camel milk was compared with that of bovine and human milk using an in vitro infant gastrointestinal digestion system. A low degree of gastric proteolysis was observed in all three kinds of milk, and a single clot was formed in camel milk. The soluble milk proteins remaining in the gastric digesta were digested rapidly and extensively in the intestinal phase, while the proteins in the camel milk clot were hydrolysed gradually. Despite several similarities, bioactive peptides unique to individual milk were identified in the three intestinal milk digesta. The results suggest that camel milk proteins are equally digestible as bovine and human milk proteins under infant gastrointestinal digestion conditions, and it may be a prospective substitute for infant formula base.

Dynamic in vitro gastric digestion behavior of goat milk: Effects of homogenization and heat treatments

The gastric digestion behavior of differently processed goat milks was investigated using a dynamic in vitro gastric digestion model, the human gastric simulator. Homogenization and heat treatment of goat milk resulted in gastric clots with highly fragmented structures. They also delayed the pH reduction during digestion, altered the chemical composition of the clots and the emptied digesta, promoted the release of calcium from the clots, and accelerated the hydrolysis and the emptying of milk proteins. The apparent density of the protein particles and the location of the homogenized fat globules changed during the digestion process, as shown in the emptied digesta of the homogenized goat milks. The effects of processing on the digestion behavior of goat milk were broadly similar to those previously reported for cow milk. However, the overall gastric digestion process of goat milk was more affected by homogenization than by heat treatments.

Investigation on the Anaphylaxis and Anti-Digestive Stable Peptides Identification of Ultrasound-Treated α-Lactalbumin during In-Vitro Gastroduodenal Digestion

Our previous studies indicated that ultrasound treatment can increase the anaphylaxis of protein. However, investigation on the anaphylaxis changes of ultrasound-treated α-lactalbumin (ALA) during digestion is lacking. The anaphylaxis of ultrasound-treated ALA and its digesta was investigated. The anti-digestive stable peptides were identified by high-resolution mass spectrometry. Ultrasound induced the tertiary structure of ALA to unfold and increased its anaphylaxis. During digestion, the anaphylaxis of both gastric and gastroduodenal digesta was further increased. There are two reasons for this phenomenon. On the one hand, linear epitopes played an important role in affecting anaphylaxis compared with the conformational epitope, and some linear epitopes were still retained on the anti-digestive stable peptides produced after gastroduodenal digestion, resulting in increased anaphylaxis after digestion. On the other hand, the presence of intact ALA molecules after digestion still remained strong anaphylaxis. Compared with the digesta of untreated ALA, the digesta of ultrasound-treated ALA possessed higher anaphylaxis. The results indicated that ultrasound increased the anaphylaxis of ALA during digestion.

Comparative Structural and Compositional Analyses of Cow, Buffalo, Goat and Sheep Cream

Factors affecting milk and milk fraction composition, such as cream, are poorly understood, with most research and human health application associated with cow cream. In this study, proteomic and lipidomic analyses were performed on cow, goat, sheep and Bubalus bubalis (from now on referred to as buffalo), bulk milk cream samples. Confocal laser scanning microscopy was used to determine the composition, including protein, lipid and their glycoconjugates, and the structure of the milk fat globules. BLAST2GO was used to annotate functional indicators of cream protein. Functional annotation of protein highlighted a broad level of similarity between species. However, investigation of specific biological process terms revealed distinct differences in antigen processing and presentation, activation, and production of molecular mediators of the immune response. Lipid analyses revealed that saturated fatty acids were lowest in sheep cream and similar in the cream of the other species. Palmitic acid was highest in cow and lowest in sheep cream. Cow and sheep milk fat globules were associated with thick patches of protein on the surface, while buffalo and goat milk fat globules were associated with larger areas of aggregated protein and significant surface adsorbed protein, respectively. This study highlights the differences between cow, goat, sheep, and buffalo milk cream, which can be used to support their potential application in functional foods such as infant milk formula.

Analysis of the Endogenous Peptidomes of Different Infant Formula Types and Human Milk

Infant formula (IF) is a commonly used replacement whenever mother’s own milk is not available. Most IFs are based on cow milk (powders, liquids). Alternatives, based on other sources such as goat milk or plants, exist. Independent of the source, IF production and composition are strictly regulated. Besides proteins, minerals, and lipids, milk contains a variety of endogenous peptides. Whereas the human milk peptidome has been studied intensively, the peptidomes of IFs have been mostly neglected. This study investigated the peptidomes of different types of first stage IF, including cow milk-based powders and liquids, and powdered goat milk-based IF, highlighting major similarities and differences to human milk. Extracted native peptidomes were analyzed by nanoRPC-ESI-MS/MS using two different fragmentation techniques allowing the confident identification of 1587 peptides. β-Casein peptides dominated in all samples. Interestingly, powdered and liquid cow milk-based IFs differed in the numbers of β- and α_S1-casein peptides, indicating processing-derived variations. However, the peptidomes of cow and goat milk-based IF appeared to be more comparable to each other than to human milk. Despite an overlap in the major source proteins, many peptide sequences were different, i.e., species-specific. Remarkably, the data indicate that the human milk peptidome might be donor-specific as well.

Role of fermented goat milk as a nutritional product to improve anemia

Goat milk, like cow milk, needs some modifications to be used as the sole source of nutrition during early infancy. For goat milk to be more like human milk and more nutritionally complete, sugar, vitamins and minerals need to be added to it and for reduction of renal solute load, it needs to be diluted. To prevent megaloblastic anemia in infants fed exclusively on goat milk, folic acid should be supplied either by adding it to goat milk or by an oral folic acid supplement. In fortification of milk products, thermal processing, fermentation, and species differences in milk folate bioavailability are three additional factors that should be considered besides absolute difference in folate concentration between goat and human milk. Whether different feeding regimes (e.g., iron and folate content of diets) influence milk folate content needs to be elucidated by more research. Our findings showed that fermented goat milk during anemia recovery can be improve antioxidant status, protection from oxidative damage to biomolecules, protective effects on testis, improve Fe and skeletal muscle homeostasis as well as improve cardiovascular health. PRACTICAL APPLICATIONS: To be used as part of a postweaning nutritionally well-balanced diet, fermented goat milk is most likely an excellent source of nutrition for the human.

PRACTICAL USE OF GOAT MILK AND COLOSTRUM

This review presents the protein and amino acid composition of both goat colostrums and milk and describes the properties of goat colostrums and milk components. In addition, the prospects of use of goat milk and colostrum in the food and cosmetics industry and the feasibility of use of goat milk for baby feeding are shown. Functional foods produced from goat milk have antioxidant, anti-inflammatory, cardioprotective, antihypertensive and antiatherogenic activities in the human body. Goat milk cosmetics are very useful for maintaining a healthy skin and are effective in treatment of various skin diseases. Infant formula based on goat milk provides comfortable digestion for babies and are better at absorbing proteins, fats and other nutrients than infant formula based on cow’s milk.

Understanding protein digestion in infants and the elderly: Current in vitro digestion models

The last decades have witnessed a surge of interest in the fate of dietary proteins during gastrointestinal (GI) digestion. Although several in vitro digestion models are available as alternatives to clinical experiments, most of them focus on the digestive conditions of healthy young adults. This study investigates the static/dynamic models used to simulate digestion in infants and the elderly and considers the related in vivo conditions. The in vitro digestive protocols targeting these two groups are summarized, and the challenges associated with the further development of in vitro digestion models are discussed. Static models rely on several factors (e.g., enzyme concentration, pH, reaction time, and rotation speed) to differentiate digestive conditions depending on age. Dynamic models can more accurately simulate the complex digestion process and allow the inclusion of further parameters (sequential secretion of digestive fluids, gradual changes in pH, peristaltic mixing, GI emptying, and the inoculation of luminal microbiota). In the case of infants, age or growth stage clarification and the differentiation of digestive protocols between full-term and preterm infants are required, whereas protocols dealing with various health statuses are required in the case of the elderly, as this group is prone to oral cavity and GI function deterioration.