Dr. Summit Shah
New research out of the Boston Children’s Hospital has demonstrated an important role of gut bacteria in food allergies. The scientists transplanted fecal material from human babies with and without food allergies into mice that had been engineered to have severe egg allergies. When mice received fecal matter from babies with food allergies, their egg allergies persisted. However, when they received fecal matter from healthy babies, they were protected from anaphylaxis - a potentially fatal allergic reaction.
Back in the 80s and 90s, researchers began observing that gut bacteria in animals appeared to play a role in preventing food allergies. Specifically, something about gut bacteria was ensuring that the immune system recognized foods as harmless, even though they were foreign. Normally, the immune system attacks foreign entities it deems harmless as a way to ensure health and safety.
In 2000, a new study was published showing that mice with a specific genetic mutation disrupted communication between gut bacteria and the immune system. What was fascinating, though, was that mice with this mutation also experienced anaphylaxis when they were exposed to peanuts.
Since this key combination of observations linking gut bacteria to food allergies, it has been shown that a causal relationship exists between the microbiome and food allergies. One specific species of bacteria, known as Anarostipes caccae, is important for preventing allergies to cow’s milk. This role of Anarostipes caccae was discovered when it was observed that mice with lower levels of this bacteria were more likely to have allergic reactions to cow’s milk and that transferring this bacteria to mice could protect against such allergic reactions.
How can this information on the connection between gut bacteria and food allergies be put to use?
Researchers have established ways to use differences in the microbiome to predict which children will outgrow their food allergies. Ongoing research into the mechanisms underlying this connection will hopefully lead to the development of strategies to prevent or treat food allergies. Clinical trials are currently underway to determine if probiotic supplements may provide an opportunity to combat food allergies.
Many asthma sufferers do not realize that there are different types of asthma diagnoses that depend on the frequency of asthma symptoms. Whereas people who suffer from asthma symptoms regularly are often diagnosed with persistent asthma, those who experience symptoms 2 days each week or less are likely to be diagnosed with intermittent asthma. Those with intermittent asthma also do not have more than 2 night flares each month.
The main feature of intermittent asthma is flare-ups occurring only a few times each month. The symptoms themselves can range in severity, but most people with intermittent asthma have mild symptoms. It is possible for those with intermittent asthma to have asthma that progresses to persistent asthma.
Whether intermittent or persistent, asthma tends to generally include the same symptoms. These symptoms include difficulty breathing, chest tightness, shortness of breath, coughing, and wheezing. Coughing tends to happen more frequently at night or following exercise. These symptoms are caused by a few different physiological activities, including inflammation in the airway and shrinking and spasms of the lungs.
Those with intermittent asthma often notice that their symptoms are triggered by specific stimuli, such as certain chemicals, smoke, pollen, cold air, or pet dander. Respiratory infections often also lead to asthma symptoms in intermittent asthma patients.
Intermittent asthma patients can manage their symptoms by avoiding their triggers, but they will often still require medical intervention as well. Treatment for intermittent asthma, however, may be different than treatment for persistent asthma. Specifically, intermittent asthma often requires fewer treatments. The treatments are likely to be short-acting beta agonists, such as albuterol - also known as a rescue inhaler - or oral corticosteroids like prednisone. Even though people with intermittent asthma may feel as though their symptoms resolve, it is important to pursue treatment to prevent severe asthma attacks.
Trying to predict whether children will develop asthma is not a new pursuit. People who have asthma themselves or who know that their children carry risk factors that may increase their children’s likelihood of getting the disease are eager to get their hands on information that can help them predict whether their children will one day have asthma. To date, most of the tools to help assess children’s risk of developing asthma have been binary, meaning that their readout simply says that a child is or is not likely to develop asthma.
A new online tool, the Pediatric Asthma Risk Score (PARS) is a free way to evaluate asthma risk in young children, and it gives a more dynamic picture of a child’s asthma risk than other tools can. PARS asks questions related to 6 known risk factors for asthma: parental asthma, race, allergy skin test results, wheezing, and difficulty breathing. The output of the tool is a percentage likelihood that the child will have asthma by the time he or she is 7 years old.
Compared to the sensitivity of the standard Asthma Predictive Index (API), that of PARS is 11% higher. Researchers hope that they will be able to incorporate more risk factors into the tool over time so that it becomes even more sensitive.
Tools like PARS can be helpful for parents not only to alleviate the worry they may feel about the potential for their child to develop asthma but also to help them to be proactive when their child is at significant risk. Those who find that their child is likely to develop asthma can learn how to best monitor their child and help to ensure that they intervene early if intervention is indeed needed.
Given that PARS is more sensitive than other tools for assessing as asthma risk in young children, it could become very useful for clinicians and parents. Other benefits of the tool are that it is free, non-invasive, and provides more information than other tools.
Even if the only time we spend at home is while sleeping, we spend a significant amount of time in our houses. For people with allergies, ridding the home of as many allergens as possible can improve quality of life and reduce allergy symptoms on a daily basis. While it may be difficult to completely remove all allergens, using certain appliances can have a large impact in decreasing the number of allergens in your home. Some of the most beneficial appliances are:
- Vacuum cleaners that have HEPA filters built into them. HEPA filters help to trap even the smallest dust particles. Using these kinds of vacuums in the house at least once a week can be incredibly helpful in getting rid of problematic allergens.
- Fresh air filters in the HVAC system. Fresh filters will trap more dust than older filters and will also keep the system operating efficiently so that air is well circulated.
- Stand-alone air purifiers. Air purifiers work by both circulating air around rooms and also trapping particles in the air. Research on the impact of air purifiers has found that when air purifiers are used properly, they can reduce particulate matter by about 50%.
- Exhaust fan over stove. Humidity in the house can lead to mold that can cause or exacerbate allergy symptoms. Using an exhaust fan over the stove - particularly when cooking with high heat - can help reduce humidity and resulting mold.
Technological innovations have been beneficial for those with allergies because they have led to the development of effective and affordable appliances that can help us combat allergy symptoms and allergic reactions. However, there are also some very simple solutions to help rid houses of allergens. For instance, replacing bedding regularly and ensuring that bedding is made of cotton rather than synthetic fibers can help to minimize allergic reactions. Switching out rugs can also get pet dander, pollen, and dust out of the house. Combining these different strategies is the best way to ensure that your house is as allergen-free as possible
Food allergies have increased over time, especially in young children, as has the consumption of highly processed foods. New research suggests that this co-occurrence may not be a coincidence. A new study has shown that food allergies in children are in fact associated with higher levels of a compound found in junk food. The compound, called advanced glycation end product (AGE), is a protein or lipid that has been exposed to sugar.
AGEs are already known to have a role in certain neurological disorders and diseases such as diabetes. They are found in processed and microwaved foods as well as in many meat products. Given the high levels of AGEs in junk food, scientists have begun to wonder if these compounds could account for the link between diet and rising food allergies.
To evaluate the relationship between AGEs and food allergies in children, researchers conducted a study comparing children who had food allergies to those with respiratory allergies and those with no allergies. There were 61 study participants, and they ranged in age from 6 to 12 years.
The scientists found that children who ate more junk food had higher levels of AGEs beneath their skin. Additionally, compared to those with respiratory allergies or no allergies at all, children with food allergies had these higher levels of subcutaneous AGE. These results suggest that the AGEs found in junk food could have something to do with the development of food allergies in children.
This new study is not the first to point to suggest that junk food could adversely impact the immune system. Another study, conducted in 2013, investigated the relationship between fast food consumption and the likelihood of developing asthma, rhinoconjunctivitis, and eczema. This study, which involved the analysis of data from nearly 320,000 adolescents and over 180,000 children found that eating fast food at least 3 times each week was associated with a significant increase in the risk of developing allergic disease.
The specific role junk food plays in allergies, asthma, and other allergic diseases is not yet clear. However, accumulating evidence suggests that these foods may be to blame not only for issues like obesity but also for the rising food allergy prevalence. Though we know that staying away from junk food is important for maintaining a healthy weight, it may be the case that avoiding these foods can also lower the risk of developing food allergies.
A new study aimed at understanding how to improve asthma control in adults over the age of 60 has found that customizing education about asthma and how to use medications significantly improves these patients’ likelihood of taking their medications. As a result of better medication adherence, these patients also experience better asthma control. Data from this randomized trial are published in JAMA Internal Medicine.
Older adults tend to suffer from worse asthma control than younger adult patients. Given that less than 40% of older asthma patients regularly use their medications, the authors of this new study hypothesized that finding ways to improve medication adherence could be the key to improving asthma control in this population.
New York City residents over the age of 59 with uncontrolled asthma participated in this trial, called the Self Management Behaviors in Older Adults (SAMBA). Each of the 406 participants was randomly assigned to receive a self-management intervention that occurred at home, a clinic-based intervention, or usual care without management support.
The researchers found that the patients who had interventions experienced better control of their asthma symptoms and better quality of life over the course of 12 months of follow-up. After a year of interventions, these patients also visited the emergency room for asthma-related issues less frequently than the control group that received no management support.
When the researchers investigated the specific medication-related behaviors, they found that those who received the interventions were more likely to take their recommended medications and correctly use their asthma inhalers than those who were not given the relevant support. Whether the interventions were provided at home or in the clinic did not affect outcomes.
These results improve our understanding of how to help older asthma patients better control their asthma symptoms, mainly by enabling them to properly follow clinicians’ medication recommendations. The results also point to the importance of customizing solutions to specific populations, which requires understanding the specific challenges that different groups of asthma patients may face.
For those with food allergies, eating out can be anxiety-provoking, as it is difficult to control what ends up on your plate. Even if the problematic ingredient is not purposefully included in a dish, cross-contamination can occur in the kitchen. The result is that people with food allergies can still come into contact with food allergens at restaurants, even if they don’t order something containing that allergen.
To complicate matters further, allergens can get into the air during cooking, so simply cooking certain foods can put restaurants at risk for exposing allergic individuals to dangerous allergens. Given the safety risks, it is important for restaurant staff to be knowledgeable about food allergies to the extent that they can minimize harmful exposure to their customers.
A recent study in Germany, published in PLOS One, evaluated 295 people working in restaurants to determine how well they understood food allergies. Over the course of 3 months, researchers conducted face-to-face interviews with restaurant staff, about half of whom were servers.
Nearly 90% of those interviewed said that they were confident that they could provide meal information related to allergies, and 46% had completed training in food allergies. Nonetheless, not even half of the restaurant staffers could correctly answer a 5-question quiz on food allergies. Only 30% could name 3 food allergens, and 35% believed the common misconception that water alleviates food allergy reactions.
Also concerning was that individuals working in restaurants demonstrated negative views towards patrons with food allergies. While nearly 20% of those interviewed said that they would rather not serve those with food allergies, 42% said that they don’t believe customers who declare allergies. Interestingly, female servers were more likely than male servers to believe those who said that they were allergic to certain foods.
These data demonstrate that there is no correlation between food allergy training and food allergy knowledge, as those who have undergone training do not appear to be more knowledgeable about food allergies than the general population. These results suggest that new training programs may need to be developed if restaurant workers are to understand food allergies. Until then, people with food allergies should be extra cautious when dining at restaurants.
Both omega-3s and omega-6, which are found in a variety of foods, appear to impact asthma symptoms in children. Interestingly though, they seem to have opposite effects on asthma symptom severity. Specifically, new evidence suggests that omega-3 intake is associated with milder asthma symptoms in children, whereas omega-6 intake is associated with more severe symptoms.
The study, published in the American Journal of Respiratory and Critical Care Medicine, involved following 135 children who live in Baltimore. The children ranged in age from 5 to 12. The researchers evaluated what the children ate and the level of air pollutants in their homes, as well as their asthma symptoms and their use of asthma medications. The children were assessed at 3 separate times: at the start of the study, after 3 months, and after 6 months.
Data from the study demonstrated that children whose blood samples had higher levels of omega-3s were more likely to have milder signs and symptoms of asthma. In contrast, the children with higher levels of omega-6s were at higher risk for more severe asthma symptoms and more severe asthmatic responses to certain pollutants in the air that are known to trigger asthma.
In addition to the correlation between omega intake and asthma symptom severity, the researchers also found that higher levels of omega-3 and omega-6 was also associated with physiological markers of asthma. Indeed, children with higher levels of omega-6s also had higher levels of immune cells associated with inflammation in their blood, whereas those with higher levels of omega-3s had lower levels of these cells.
Foods like fish, nuts, and seeds contain high levels of omega-3s, whereas omega-6s are more easily found in vegetable oils. These new data indicate that omega-3s may help to mitigate asthma symptom severity. Though the details on how omega-3s may confer their benefits to those with asthma is not yet clear, omega-3s are known to have other health benefits and are found in healthy foods. It is therefore reasonable for those with asthma to increase their intake of omega-3s, as they may enjoy benefits from more omega-3 consumption.
Over 6 million children in the U.S. suffer from asthma, according to the Centers of Disease Control and Prevention (CDC), which is approximately 12% of all children in our country. However, the prevalence of asthma amongst children is not evenly distributed between distinct demographics. Instead, minority children, those who are obese, and those who reside in urban locations are more likely to suffer from the condition.
New research, funded by the National Institute of Environmental Health and conducted by scientists at Johns Hopkins University, has focused on how to protect children in urban environments from asthma. The study, published in the Journal of Allergy and Clinical Immunology: In Practice, specifically investigated the potential of vitamin D - which has been increasingly recognized as a vitamin in which people across the U.S. are deficient - to affect these children’s susceptibility to asthma and asthma symptoms.
The researchers studied 120 children in Baltimore who had been diagnosed with asthma, about 40 of whom were also obese. The scientists evaluated the children 4 separate times over a 9-month period, looking at the children’s asthma symptoms, the level of air pollution in their homes, and the amount of vitamin D in their blood.
The results of the study showed that for obese children with asthma, low vitamin D levels were associated with higher risks of being impacted by indoor air pollution. In other words, obese children who lived in homes that had the highest levels of air pollution had fewer asthma symptoms if their vitamin D levels were higher.
Future research should help to clarify how exactly vitamin D may confer its respiratory benefits, but experts agree that it is likely to work through its antioxidant properties and to thereby affect pathways of the immune system. For now, they argue that our growing knowledge of the link between vitamin D and asthma amongst obese children in urban communities justifies higher levels of vitamin D intake. While vitamin D levels can be improved through sunlight, consuming dietary supplements and food high in vitamin D, such as fatty fish and milk, may be a more reliable way to increase vitamin D levels.
In attempts to develop therapies for seasonal allergies, researchers in Austria are using animals not often associated with scientific research: camels.
There are currently about 800 million people worldwide suffering from seasonal allergies induced by pollen, and though there are several treatment options on the market, seasonal allergy sufferers often struggle to control their symptoms and see their symptoms worsen over time. New treatments are therefore continuously sought, and research into seasonal allergies remains a robust line of investigation.
Camels provide a unique opportunity for allergy treatment because, unlike other animals, who tend to produce antibodies containing what are referred to as two “heavy” and two “light” chains, camels are able to produce single-chained antibodies that are more capable of binding strongly to allergens and thereby preventing their problematic impact on the immune system.
Normally, upon exposure to an allergen like pollen, those who develop allergies will begin to produce antibodies against that allergen. The next time they are exposed to the allergen, those antibodies will bind to the allergen and set off a chain reaction in the immune system that leads to inflammation and allergy symptoms.
If we can produce allergen-specific antibodies that more readily bind allergens like pollen, we can prevent our own antibodies from binding to those allergens and thus prevent the resulting allergy symptoms. This logic is driving the high-performance nanobody technology project taking place in Vienna, where researchers are injecting allergens into camels and obtaining antibodies from their blood.
The hope is that these antibodies will enable us to protect against seasonal allergies through the development of treatments that will be used locally, in the nose or in the eyes. The researchers expect that it will take between 8 and 10 years to develop these therapies, and further investigation will help determine the feasibility and timeline for such treatments.