Allergies
Episodes
Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
Comprehensive overview: Breast milk's nutritional and non-nutritional components, and health benefits for mother and infant through breastfeeding
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Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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Rhonda Exercise Aging Vitamin C Omega-3 Stem Cells Fasting Magnesium Vitamin E Vaccine Vitamin K Allergies Resveratrol Sauna Time-Restricted Eating Blood Sugar Breast MilkDr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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Comprehensive overview: Breast milk's nutritional and non-nutritional components, and health benefits for mother and infant through breastfeeding
Topic Pages
News & Publications
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Food antigens, proteins in meat and milk that trigger allergic reactions, activate immune responses that reduce the risk of small intestinal tumors. www.frontiersin.org
Proteins in milk, meat, and other foods can trigger allergic reactions in some people. However, these proteins—called antigens—can also interact with the immune system to suppress small intestinal tumors. A recent study in mice found that food antigens help activate immune responses in the small intestine, potentially reducing the risk of tumors.
Researchers fed mice genetically prone to developing intestinal tumors—similar to the genetic predisposition to familial adenomatous polyposis in humans—an antigen-free diet to pinpoint the role of food components in immune activation. They also depleted immune tissues in the animals' small intestines called Peyer’s patches to investigate how food antigens trigger immune cells.
They found that food antigens activate immune cells in Peyer’s patches, suppressing small intestinal tumor formation. This immune response is crucial for maintaining a tumor-suppressive environment in the gut.
These findings suggest that food antigens help protect against small intestinal tumors in mice by activating immune cells that promote tumor suppression, highlighting their potential as a protective factor in gut health. The microbiome plays a key role in gut health, too. Learn more in this episode featuring Dr. Eran Elinav.
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The immune system, recognized for its role in depression, now understood to shape allergen avoidance behavior. www.sciencedaily.com
The immune system plays a critical role in protecting human health. However, a recent study in mice shows that the immune system may influence behavior, too. Mice exposed to allergens – substances that trigger allergies – avoided those substances.
Researchers studied two groups of mice: one that was predisposed to egg allergy and one that was not. They exposed the two groups to water that contained ovalbumin, a protein in eggs that triggers allergic reactions.
They found that regions of the predisposed animals' brains that respond to unpleasant stimuli became active when they ingested allergens, causing them to avoid the ovalbumin-containing water. The mechanisms driving this behavior involved activation of IgE antibodies and mast cells (essential immune system components), which, in turn, triggered the activity of key immune-related molecules – cysteinyl leukotrienes and growth and differentiation factor-15 (GDF-15). Interestingly, the animals' avoidance behavior occurred before allergy-associated gut inflammation manifested.
Cysteinyl leukotrienes are pro-inflammatory lipid mediators produced by various immune cells, including mast cells, eosinophils, basophils, and macrophages. GDF-15 is a cytokine that increases in response to stress, infection, and inflammation. It increases in aging, suppressing immune responses.
These findings suggest that the immune system can shape behavior in response to allergens in mice, potentially protecting against harmful exposures. The immune system also influences behavior by inducing depressive symptoms during periods of acute or, alternatively, chronic inflammation. Learn more in this clip featuring Dr. Charles Raison.
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Experimental vaccine may prevent peanut allergy. newatlas.com
A recent study demonstrated that an experimental mRNA-based vaccine prevented peanut allergy in mice. The vaccine effectively induced peanut protein tolerance, reducing or preventing symptoms of allergy.
Researchers developed a lipid nanoparticle vaccine that delivered mRNA-encoded peanut allergen and administered it to mice that are prone to peanut allergy. Then they exposed the mice to peanut protein and assessed their immune response.
They found that the mRNA vaccine induced the production of T regulatory cells, a specialized type of T cells that suppress the body’s immune response. The vaccine also reduced cytokine production, antibody synthesis, and mast cell release – indicators of an allergic response.
Peanut allergy is one of the most common food allergies, affecting approximately 2 percent of adults and children in the United States. Typically manifesting early in life, symptoms of peanut allergy include rashes, shortness of breath, and life-threatening anaphylaxis.
mRNA-based vaccines contain the genetic material to encode a single protein that, when injected into the body, induces antibody production against that protein – in this case, a peanut allergen. Because mRNA degrades easily, it must be encapsulated in lipid nanoparticles.
These findings suggest that an mRNA-based vaccine prevents peanut allergy in mice. Although mRNA-based vaccines have been used in clinical trials for nearly two decades, this study reflects their first use against an allergen. Learn more about mRNA vaccines in this clip featuring Dr. Roger Seheult.
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Testosterone protects men from developing allergic asthma by inhibiting a certain type of immune cell, mouse study suggests. (2017) www.sciencedaily.com
From the article:
“There is a very interesting clinical observation that women are more affected and develop more severe asthma than men, and so we tried to understand why this was happening,” Dr Seillet said.
“Our research shows that high levels of testosterone in males protect them against the development of allergic asthma. We identified that testosterone is a potent inhibitor of innate lymphoid cells, a newly-described immune cell that has been associated with the initiation of asthma.”
The research team found that innate lymphoid cells – or ILC2s – ‘sensed’ testosterone and responded by halting production of the cells.
“Testosterone directly acts on ILC2s by inhibiting their proliferation,” Dr Seillet said. “So in males, you have less ILC2s in the lungs and this directly correlates with the reduced severity of asthma.”
ILC2s are found in the lungs, skin and other organs. These cells produce inflammatory proteins that can cause lung inflammation and damage in response to common triggers for allergic asthma, such as pollen, dust mites, cigarette smoke and pet hair.
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Butyrate, a short-chain fatty acid produced in the gut, reduces skin allergies.
The skin is an important biological barrier that plays critical roles in the body’s innate immune response. Skin allergies, which typically appear early in life and can impair barrier function, have become more common in recent decades. Findings from a recent study suggest that butyrate, a short-chain fatty acid produced in the gut, reduces atopic dermatitis, a type of skin allergy.
Short-chain fatty acids are fatty acids that contain fewer than six carbons in their chemical structure. They are produced by the gut microbiota during the fermentation of dietary fiber and are crucial to gut health. Short-chain fatty acids may play roles in the prevention and treatment of metabolic syndrome, inflammatory bowel disorders, and certain types of cancer. Some evidence suggests they can cross the blood-brain barrier to affect brain function. The principal short-chain fatty acids produced in the human gut are acetate, propionate, and butyrate.
The investigators first exposed two groups of mice to an allergen that induces a skin condition similar to atopic dermatitis. They fed both groups a low-fiber diet, but they supplemented one group with inulin, a type of fiber that undergoes microbial fermentation in the gut to produce butyrate. They supplemented the other group with cellulose, which does not readily ferment. They found that compared to the cellulose-supplemented mice, the mice that ate the inulin-supplemented diet had less severe skin disease, better barrier function, and a milder immune response, which they attributed to butyrate.
Next, they tracked the movement of butyrate in the animals' bodies and determined that it traveled quickly from the gut to the skin (about 45 minutes), where it directly influenced the mitochondrial metabolism of keratinocytes, the dominant cell type in the epidermal layer of the skin. Finally, they analyzed gene expression in skin collected from both groups of mice and observed a twofold increase in gene expression related to immunity and barrier function in the butyrate-exposed mice.
These findings suggest that butyrate influences skin health and reduces skin allergies. Learn more about the beneficial health effects of butyrate in our overview article.
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A pilot study to investigate the immune modulatory effects of fasting in steroid-naïve mild asthmatics www.ncbi.nlm.nih.gov
A fasting mimetic diet blunts inflammation and intermittent fasting has shown ameliorative effects in obese asthmatics. To examine whether canonical inflammatory pathways linked with asthma are modulated by fasting we designed a pilot study in mild asthmatic subjects to assess the effect of fasting on: the NLRP3 inflammasome; Th2 cell activation and airway epithelial cell cytokine production. Subjects with documented reversible airway obstruction and stable mild asthma were recruited into this study where pulmonary function testing (PFT) and peripheral blood mononuclear cells (PBMCs) extraction was performed 24 hours after fasting, with repeated PFT-testing and blood draw 2.5 hours after refeeding. PFT’s were not changed by a prolonged fast. However, steroid-naïve mild asthmatics showed fasting-dependent blunting of the NLRP3 inflammasome. Furthermore, PBMCs from these fasted asthmatics co-cultured with human epithelial cells resulted in blunting of house dust mite-induced epithelial cell cytokine production, and reduced CD4+ T cell Th2 activation compared to refed samples. This pilot study shows that prolonged fasting blunts the NLRP3 inflammasome and Th2 cell activation in steroid-naïve asthmatics, as well as diminishes airway epithelial cell cytokine production. This identifies a potential role for nutrient-level dependent regulation of inflammation in asthma. Our findings support the evaluation of this concept in a larger study, as well as the potential development of caloric restriction interventions for the treatment of asthma.