Effects of dietary protein types on immune responses and levels of infection with Eimeria vermiformis in mice

Modulation of gut-microbiota through probiotics and dietary interventions to improve host health

Dietary patterns play an important role in regards to the modulation and control of the gut microbiome composition and function. The interaction between diet and microbiota plays an important role in order to maintain intestinal homeostasis, which ultimately affect the host's health. Diet directly impacts the microbes that inhabit the gastrointestinal tract (GIT), which then contributes to the production of secondary metabolites, such as short-chain fatty acids, neurotransmitters, and antimicrobial peptides. Dietary consumption with genetically modified probiotics can be the best vaccine delivery vector and protect cells from various illnesses. A holistic approach to disease prevention, treatment, and management takes these intrinsically linked diet-microbes, microbe-microbe interactions, and microbe-host interactions into account. Dietary components, such as fiber can modulate beneficial gut microbiota, and they have resulting ameliorative effects against metabolic disorders. Medical interventions, such as antibiotic drugs can conversely have detrimental effects on gut microbiota by disputing the balance between Bacteroides and firmicute, which contribute to continuing disease states. We summarize the known effects of various dietary components, such as fibers, carbohydrates, fatty acids, vitamins, minerals, proteins, phenolic acids, and antibiotics on the composition of the gut microbiota in this article in addition to the beneficial effect of genetically modified probiotics and consequentially their role in regards to shaping human health. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of Soy–Whey Protein Nutritional Supplementation on Hematopoiesis and Immune Reconstitution in an Allogeneic Transplanted Mice

Profound malnutrition and immunodeficiency are serious negative effects of radiotherapy and bone marrow transplantation for hematologic malignancy patients. This study aimed to evaluate the effects of nutritional supplementation with a soy–whey protein mixture on hematopoietic and immune reconstitution in an allogeneic transplant mouse model. Male BALB/c (H-2Kd) mice, 6–8 weeks-old, were divided randomly into five groups and then provided with different protein nutrition support. After 28 days, blood samples, bone marrow, spleen, and thymus were harvested to measure the effects. The results showed that soy–whey blended protein supplements promoted hematopoietic stem cell engraftment, body weight recovery, and the recovery of white blood cells, lymphocytes, and neutrophils; triggered the expansion of hematopoietic stem cells and progenitor cell pools by increasing the numbers of the c-kit⁺ progenitor, Lin-Sca1⁺c-kit⁺, short-term hematopoietic stem cells, and multipotent progenitors; enhanced thymus re-establishment and splenic subset recovery in both organ index and absolute number; improved overall nutritional status by increasing total serum protein, albumin, and globulin; protected the liver from radiation-induced injury, and increased antioxidant capacity as indicated by lower concentrations of alanine aminotransferase, aspartate aminotransferase, malondialdehyde, and 4-hydroxynonenal. This study indicated that soy–whey blended protein as important nutrients, from both plant and animal sources, had a greater positive effect on patients with hematological malignancies to accelerate hematopoiesis and immune reconstitution after bone marrow transplantation.

Dairy-Derived and Egg White Proteins in Enhancing Immune System Against COVID-19

Coronavirus disease (COVID-19) is a global health challenge, caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) triggers a plethora of respiratory disturbances and even multiple organs failure that can be fatal. Nutritional intervention is one of the key components toward to a proper management of COVID-19 patients, especially in those requiring medication, and should thus be considered the first-line treatment. Immuno-modulation and -stimulation are currently being explored in COVID-19 management and are gaining interest by food and pharmaceutical industries. Various dietary combinations, bioactive components, nutrients and fortified foods have been reported to modulate inflammation during disease progression. Dietary combinations of dairy-derived products and eggs are gaining an increasing attention given the huge immunomodulatory and anti-inflammatory properties attributed to some of their chemical constituents. Eggs are complex dietary components containing many essential nutrients and bioactive compounds as well as a high-quality proteins. Similarly, yogurts can replenish beneficial bacteria and contains macronutrients capable of stimulating immunity by enhancing cell immunity, reducing oxidative stress, neutralizing inflammation and regulating the intestinal barriers and gut microbiome. Thus, this review highlights the impact of nutritional intervention on COVID-19 management, focusing on the immunomodulatory and inflammatory effects of immune-enhancing nutrients.

Milk-Derived Extracellular Vesicles in Inter-Organism, Cross-Species Communication and Drug Delivery

Milk is considered as more than a source of nutrition for infants and is a vector involved in the transfer of bioactive compounds and cells. Milk contains abundant quantities of extracellular vesicles (EVs) that may originate from multiple cellular sources. These nanosized vesicles have been well characterized and are known to carry a diverse cargo of proteins, nucleic acids, lipids and other biomolecules. Milk-derived EVs have been demonstrated to survive harsh and degrading conditions in gut, taken up by various cell types, cross biological barriers and reach peripheral tissues. The cargo carried by these dietary EVs has been suggested to have a role in cell growth, development, immune modulation and regulation. Hence, there is considerable interest in understanding the role of milk-derived EVs in mediating inter-organismal and cross-species communication. Furthermore, various attributes such as it being a natural source, as well as its abundance, scalability, economic viability and lack of unwarranted immunologic reactions, has generated significant interest in deploying milk-derived EVs for clinical applications such as drug delivery and disease therapy. In this review, the role of milk-derived EVs in inter-organismal, cross-species communication and in drug delivery is discussed.

Diet-Microbe-Host Interactions That Affect Gut Mucosal Integrity and Infection Resistance

The gastrointestinal tract microbiome plays a critical role in regulating host innate and adaptive immune responses against pathogenic bacteria. Disease associated dysbiosis and environmental induced insults, such as antibiotic treatments can lead to increased susceptibility to infection, particularly in a hospital setting. Dietary intervention is the greatest tool available to modify the microbiome and support pathogen resistance. Some dietary components can maintain a healthy disease resistant microbiome, whereas others can contribute to an imbalanced microbial population, impairing intestinal barrier function and immunity. Characterizing the effects of dietary components through the host-microbe axis as it relates to gastrointestinal health is vital to provide evidence-based dietary interventions to mitigate infections. This review will cover the effect of dietary components (carbohydrates, fiber, proteins, fats, polyphenolic compounds, vitamins, and minerals) on intestinal integrity and highlight their ability to modulate host-microbe interactions as to improve pathogen resistance.

Applications for α-lactalbumin in human nutrition

α-Lactalbumin is a whey protein that constitutes approximately 22% of the proteins in human milk and approximately 3.5% of those in bovine milk. Within the mammary gland, α-lactalbumin plays a central role in milk production as part of the lactose synthase complex required for lactose formation, which drives milk volume. It is an important source of bioactive peptides and essential amino acids, including tryptophan, lysine, branched-chain amino acids, and sulfur-containing amino acids, all of which are crucial for infant nutrition. α-Lactalbumin contributes to infant development, and the commercial availability of α-lactalbumin allows infant formulas to be reformulated to have a reduced protein content. Likewise, because of its physical characteristics, which include water solubility and heat stability, α-lactalbumin has the potential to be added to food products as a supplemental protein. It also has potential as a nutritional supplement to support neurological function and sleep in adults, owing to its unique tryptophan content. Other components of α-lactalbumin that may have usefulness in nutritional supplements include the branched-chain amino acid leucine, which promotes protein accretion in skeletal muscle, and bioactive peptides, which possess prebiotic and antibacterial properties. This review describes the characteristics of α-lactalbumin and examines the potential applications of α-lactalbumin for human health.

Protein Malnutrition Modifies Innate Immunity and Gene Expression by Intestinal Epithelial Cells and Human Rotavirus Infection in Neonatal Gnotobiotic Pigs

Malnutrition and rotavirus infection, prevalent in developing countries, individually and in combination, affect the health of millions of children, compromising their immunity and increasing the rates of death from infectious diseases. However, the interactions between the two and their combined effects on immune and intestinal functions are poorly understood. We have established the first human infant microbiota-transplanted neonatal pig model of childhood malnutrition that reproduced the impaired immune, intestinal, and other physiological functions seen in malnourished children. This model can be used to evaluate relevant dietary and other health-promoting interventions. Our findings provide an explanation of why adequate nutrition alone may lack efficacy in malnourished children.

Malnutrition affects millions of children in developing countries, compromising immunity and contributing to increased rates of death from infectious diseases. Rotavirus is a major etiological agent of childhood diarrhea in developing countries, where malnutrition is prevalent. However, the interactions between the two and their combined effects on immune and intestinal functions are poorly understood. In this study, we used neonatal gnotobiotic (Gn) pigs transplanted with the fecal microbiota of a healthy 2-month-old infant (HIFM) and fed protein-deficient or -sufficient bovine milk diets. Protein deficiency induced hypoproteinemia, hypoalbuminemia, hypoglycemia, stunting, and generalized edema in Gn pigs, as observed in protein-malnourished children. Irrespective of the diet, human rotavirus (HRV) infection early, at HIFM posttransplantation day 3 (PTD3), resulted in adverse health effects and higher mortality rates (45 to 75%) than later HRV infection (PTD10). Protein malnutrition exacerbated HRV infection and affected the morphology and function of the small intestinal epithelial barrier. In pigs infected with HRV at PTD10, there was a uniform decrease in the function and/or frequencies of natural killer cells, plasmacytoid dendritic cells, and CD103⁺ and apoptotic mononuclear cells and altered gene expression profiles of intestinal epithelial cells (chromogranin A, mucin 2, proliferating cell nuclear antigen, SRY-Box 9, and villin). Thus, we have established the first HIFM-transplanted neonatal pig model that recapitulates major aspects of protein malnutrition in children and can be used to evaluate physiologically relevant interventions. Our findings provide an explanation of why nutrient-rich diets alone may lack efficacy in malnourished children.

IMPORTANCE Malnutrition and rotavirus infection, prevalent in developing countries, individually and in combination, affect the health of millions of children, compromising their immunity and increasing the rates of death from infectious diseases. However, the interactions between the two and their combined effects on immune and intestinal functions are poorly understood. We have established the first human infant microbiota-transplanted neonatal pig model of childhood malnutrition that reproduced the impaired immune, intestinal, and other physiological functions seen in malnourished children. This model can be used to evaluate relevant dietary and other health-promoting interventions. Our findings provide an explanation of why adequate nutrition alone may lack efficacy in malnourished children.

Supplementation of fermented Maillard-reactive whey protein enhances immunity by increasing NK cell activity

Objective: The objective of this study was to investigate the impact of supplementation with fermented Maillard-reactive whey protein (F-MRP) on natural killer (NK) cell activity, circulating cytokines, and serum protein levels.

Silkworm Sericin: Properties and Biomedical Applications

Silk sericin is a natural polymer produced by silkworm, Bombyx mori, which surrounds and keeps together two fibroin filaments in silk thread used in the cocoon. The recovery and reuse of sericin usually discarded by the textile industry not only minimizes environmental issues but also has a high scientific and commercial value. The physicochemical properties of the molecule are responsible for numerous applications in biomedicine and are influenced by the extraction method and silkworm lineage, which can lead to variations in molecular weight and amino acid concentration of sericin. The presence of highly hydrophobic amino acids and its antioxidant potential make it possible for sericin to be applied in the food and cosmetic industry. The moisturizing power allows indications as a therapeutic agent for wound healing, stimulating cell proliferation, protection against ultraviolet radiation, and formulating creams and shampoos. The antioxidant activity associated with low digestibility of sericin that expands the application in the medical field, such as antitumour, antimicrobial and anti-inflammatory agent, anticoagulant, acts in colon health, improving constipation and protects the body from obesity through improved plasma lipid profile. In addition, the properties of sericin allow its application as a culture medium and cryopreservation, in tissue engineering and for drug delivery, demonstrating its effective use, as an important biomaterial.

Immunomodulatory and antiparasitic effects of garlic extract on Eimeria vermiformis-infected mice

We investigated the immunomodulatory and parasiticidal effects of garlic extract on coccidiosis caused by Eimeria vermiformis infection in male ICR mice. One group received garlic extract daily until the end of the experiment by the oral route from 10 days prior to oral infection with 300 sporulated E. vermiformis oocysts (infected-garlic(+)). The other group served as a control positive with E. vermiformis infection alone (infected-garlic(-)). In the infected-garlic(+) group, garlic extract treatment induced a significant reduction in fecal oocyst output when compared with the infected-garlic(-) group. Histopathological, immunohistochemical, and gene expression analysis for inflammatory cytokines in ileal tissues showed that the garlic extract treatment impaired intracellular development of E. vermiformis during the early stages by increasing the number of intraepithelial CD8(+) T cells and decreasing IL-10 expression. This induced cell cytotoxicity which was reflected by a decrease in oocyst numbers in the intestinal villi and the feces, indicating anticoccidial effects of the garlic extract. However, further studies to explore the precise mechanism of the observed effects of garlic treatment during Eimeria infection are needed to verify our results.

Effects of brood pheromone (SuperBoost) on consumption of protein supplement and growth of honey bee (Hymenoptera: Apidae) colonies during fall in a northern temperate climate

Honey bee, Apis mellifera L. (Hymenoptera: Apidae), nutrition is vital for colony growth and maintenance of a robust immune system. Brood rearing in honey bee colonies is highly dependent on protein availability. Beekeepers in general provide protein supplement to colonies during periods of pollen dearth. Honey bee brood pheromone is a blend of methyl and ethyl fatty acid esters extractable from cuticle of honey bee larvae that communicates the presence of larvae in a colony. Honey bee brood pheromone has been shown to increase protein supplement consumption and growth of honey bee colonies in a subtropical winter climate. Here, we tested the hypothesis that synthetic brood pheromone (SuperBoost) has the potential to increase protein supplement consumption during fall in a temperate climate and thus increase colony growth. The experiments were conducted in two locations in Oregon during September and October 2009. In both the experiments, colonies receiving brood pheromone treatment consumed significantly higher protein supplement and had greater brood area and adult bees than controls. Results from this study suggest that synthetic brood pheromone may be used to stimulate honey bee colony growth by stimulating protein supplement consumption during fall in a northern temperate climate, when majority of the beekeepers feed protein supplement to their colonies.

The effect of diet on protein concentration, hypopharyngeal gland development and virus load in worker honey bees (Apis mellifera L.)

Elucidating the mechanisms by which honey bees process pollen vs. protein supplements are important in the generation of artificial diets needed to sustain managed honeybees. We measured the effects of diet on protein concentration, hypopharyngeal gland development and virus titers in worker honey bees fed either pollen, a protein supplement (MegaBee), or a protein-free diet of sugar syrup. Workers consumed more pollen than protein supplement, but protein amounts and size of hypopharyngeal gland acini did not differ between the two feeding treatments. Bees fed sugar syrup alone had lower protein concentrations and smaller hypopharyngeal glands compared with the other feeding treatments especially as the bees aged. Deformed wing virus was detected in workers at the start of a trial. The virus concentrations increased as bees aged and were highest in those fed sugar syrup and lowest in bees fed pollen. Overall results suggest a connection between diet, protein levels and immune response and indicate that colony losses might be reduced by alleviating protein stress through supplemental feeding.

Supplemental dietary whey protein concentrate reduces rotavirus-induced disease symptoms in suckling mice

Rotavirus-induced diarrhea is a common infection that results in the death of nearly 500,000 children annually. Currently, no large-scale preventative treatments or vaccines exist. Because some whey protein concentrates (WPC) were shown to contain bioactive ingredients that may activate immune cells and/or prevent infection, the current study was conducted to assess whether the proprietary WPC IMUCARE (WPC-IC) could protect against rotavirus. Suckling BALB/c mice were treated by gavage once daily with WPC-IC or with the control protein bovine serum albumin from the age of 9 to 17 d, and were infected with murine rotavirus at the age of 11 d. Disease symptoms were graded as mild, moderate, or severe, and viral shedding was measured in fecal samples during the postinfection period. Severe diarrhea occurred in 63% of control mice; this was significantly reduced to 36% in WPC-IC-fed mice. Severe diarrhea occurred for a 4-d period in the control group but only for a 2-d period in the WPC-IC group. Although the mean viral load per mouse did not differ between the groups, the proportion of mice shedding high levels of the virus in the feces postinfection was significantly lower in the WPC-IC group on d 13, 16, and 17, and significantly higher on d 14. Rotavirus-specific antibody levels in serum and gut fluid did not differ between groups. Thus, prophylactic treatment with WPC-IC may reduce rotaviral disease by decreasing the prevalence of severe diarrhea and by decreasing the time period during which severe symptoms and high viral shedding occur.

Lack of sexual dimorphism in alcohol-induced liver damage (ALD) in rats treated chronically with ethanol-containing low carbohydrate diets: The role of ethanol metabolism and endotoxin

Evidence has been presented suggesting that females are significantly more susceptible to alcohol-induced liver damage (ALD) than males. In the current study, we examined sexual dimorphism in hepatic pathology, metabolism and cytokine profiles using two different rat models of ALD. Male and female Sprague-Dawley or Wistar rats were fed ethanol-containing low-carbohydrate liquid diets using oral or intragastric methods for 42 or 60 days. In both models, ethanol treatment produced similar significant liver hyperplasia accompanied by increases in plasma ALT, steatosis, inflammation and necrosis (p < 0.05). Greater pathology scores were observed in the intragastrically infused rats. Males did not differ significantly from females in serum ALT values or pathology despite greater elevations in TNFalpha and IL-1beta mRNAs in ethanol-treated female rat livers (p < 0.05). Furthermore, there was no sexual dimorphism in blood ethanol concentrations or CYP2E1-induction even though sexually dimorphic alterations in other hepatic cytochrome P450 enzymes were observed. These data do not support previous observations that female rats have a greater susceptibility to ethanol-induced hepatotoxicity than males.

Developmental immunotoxicity of lead in the rat: influence of maternal diet

The effect of maternal dietary protein intake on lead-induced developmental immunotoxicity was studied in female Fischer 344 rats receiving lead acetate (250 ppm) or sodium acetate (control) in the drinking water during breeding and pregnancy until parturition. Dams were fed isocaloric diets (either 20% casein or 10% casein) from 2 wk prior to mating until the end of lactation. After weaning, dams and female offspring were given the 20% casein diet and regular water. Immune function was assessed in dams at 8 wk postpartum and in offspring at 13 wk of age. Dams showed no marked difference in any of the immune endpoints examined, regardless of diet or lead treatment. In contrast, lead exposure during early development produced a subsequent significant reduction of both the delayed-type hypersensitivity response and interferon gamma production in adult offspring independent of maternal diet. Lead-exposed offspring from the high-dietary-protein group had significantly elevated production of both interleukin-4 and tumor necrosis factor alpha(TNF-alpha) with increased relative spleen weight and a decreased body weight compared to offspring in the lead control group. In contrast, lead-exposed offspring from dams receiving the low-protein diet had no marked change in TNF-alpha levels, relative spleen weight, or body weight, while interleukin-4 levels were significantly reduced compared with the lead control group. In conclusion, maternal dietary protein intake can modulate the immunotoxic effects of lead exposure during early development. This occurred at levels of protein intake and doses of lead exposure that produced no detectable effect on the maternal immune system.

Effect of dietary whey protein concentrate on primary and secondary antibody responses in immunized BALB/c mice

Proteins derived from the whey fraction of bovine milk are known to modulate immune responses. We have previously described a rennet whey protein concentrate (WPC) that can boost intestinal tract antibody responses to orally administered T-dependent antigens. In the present study, we investigated the effects of feeding WPC to mice on specific antibody responses to several orally or parenterally administered antigens, including influenza vaccine, diphtheria and tetanus toxoids, poliomyelitis vaccine, ovalbumin and cholera toxin sub-unit. WPC-fed mice produced elevated levels of antigen-specific intestinal tract and serum antibodies against all tested antigens, compared to mice that were fed a standard chow diet. Both primary and secondary intestinal tract antibody responses were elevated by WPC feeding, while only secondary serum responses were increased in WPC-fed mice. Significant up-regulation of intestinal tract antibody was observed within 2 weeks of primary oral immunizations. A period of pre-feeding with WPC, prior to commencement of immunization, did not alter the kinetics or magnitude of immune enhancement. These results identify bovine WPC as a potentially important dietary protein supplement, capable of enhancing humoral immune responses to a range of heterologous antigens.