B6-dependent protein, potentially opening avenues for new antibiotics and drugs to battle diseases such as drug-resistant tuberculosis, malaria, and diabetes.
Specifically, the team used neutron crystallography to study the location of hydrogen atoms in aspartate aminotransferase, or AAT, an enzyme vital to the metabolism of certain amino acids. “We visualized the first neutron structure of a vitamin B6 enzyme that belongs to a large protein family with hundreds of members that exist in nature,” said Oak Ridge National Laboratory’s (ORNL) Andrey Kovalevsky, a senior co-author of the study, which was published in Nature Communications. Vitamin B6-dependent proteins are part of a diverse group of enzymes that conduct over a hundred different chemical reactions in cells. The enzymes are of interest to biomedical, as well as bioenergy, researchers because of their role in metabolizing amino acids and other cell nutrients.
“These enzymes are unique in that each one performs a specific chemical reaction with exquisite accuracy while suppressing other viable chemical transformations,” Kovalevsky said. “How they accomplish this is not well understood, but it is of great significance for drug design.” The team’s previous research predicted that hydrogen atoms move in and around the enzyme’s active site, where the chemical reaction takes place, indicating that the hydrogen atoms’ positioning controls the reaction type. Knowing the precise location of hydrogen atoms can explain why the behavior of these enzymes is so specific, but hydrogen is hard to detect with standard methods such as X-ray crystallography.
To directly determine the positions of hydrogen atoms within AAT, the ORNL-led team turned to neutron diffraction techniques. The researchers exposed fine protein crystals to neutrons using the IMAGINE beamline at ORNL’s High Flux Isotope Reactor and the LADI-III beamline at the Institut Laue-Langevin in Grenoble, France. Surprisingly, the team observed a reaction within one AAT protein biomolecule while another AAT biomolecule was unchanged, providing a before-and-after perspective of the enzyme-catalyzed chemical reaction. “The data revealed that in one of the enzyme’s biomolecular structures the covalent bonds reorganized after a chemical reaction occurred in the active site and, in another, the reaction had not taken place,” Kovalevsky said. “Essentially, we were able to obtain two structures in one crystal, which has never been done before for any protein using neutrons.”
With this knowledge, the team will run molecular simulations to determine the hydrogen atoms’ specific behavior when interacting with the enzyme. The results could be useful in guiding the future design of novel medicines against multidrug-resistant tuberculosis, malaria, diabetes and antibiotic-resistant bacteria. “This study highlights how neutrons are an unrivaled probe for identifying the location of hydrogen atoms in biological systems, providing us with an unprecedented level of structural detail for this important enzyme,” LADI-III beamline scientist Matthew Blakeley said.
Adapted from: Steven Dajnowicz, Ryne C. Johnston, Jerry M. Parks, Matthew P. Blakeley, David A. Keen, Kevin L. Weiss, Oksana Gerlits, Andrey Kovalevsky, Timothy C. Mueser. Direct visualization of critical hydrogen atoms in a pyridoxal 5′-phosphate enzyme. Nature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-01060-y
Nutrition Daily Nugget
Eat the rainbow! A fun and tasty way to make sure your family is eating a good variety of fruits and vegetables is to eat as many different colors as you can each day.
Researchers have found that inducing a biochemical alteration in brain proteins via the dietary supplement glucosamine was able to rapidly dampen that pathological hyperexcitability in rat and mouse models. These results represent a potentially novel therapeutic target for the treatment of seizure disorders, and they show the need to better understand the physiology underlying these neural and brain circuit changes.
Seizure disorders, including epilepsy, are associated with pathological hyperexcitability in brain neurons. Unfortunately, there are limited available treatments that can prevent this hyperexcitability. However, the *University of Alabama at Birmingham researchers have found that inducing a biochemical alteration in brain proteins via the dietary supplement glucosamine was able to rapidly dampen that pathological hyperexcitability in rat and mouse models.
These results represent a potentially novel therapeutic target for the treatment of seizure disorders, and they show the need to better understand the physiology underlying these neural and brain circuit changes. Proteins are the workhorses of living cells, and their activities are tightly and rapidly regulated in responses to changing conditions. Adding or removing a phosphoryl group of proteins is a well-known regulator of many proteins, and it is estimated that human proteins may have as many as 230,000 sites for phosphorylation. A lesser-known regulation comes from the addition or removal of N-acetylglucosamine to proteins, which is usually controlled by glucose, the primary fuel for neurons. Several years ago, neuroscientist Lori McMahon, Ph.D., professor of cell, developmental and integrative biology at UAB, found out from her colleague John Chatham, D.Phil., a UAB professor of pathology and a cardiac physiologist, that brain cells had the second-highest amounts of proteins with N-acetylglucosamine, or O-GlcNAcylation, in the body.
At the time, very little was known about how O-GlcNAcylation might affect brain function, so McMahon and Chatham started working together. In 2014, McMahon and Chatham, in a study led by graduate student Erica Taylor and colleagues, reported that acute increases in protein O-GlcNAcylation caused long-term synaptic depression, a reduction in neuronal synaptic strength, in the hippocampus of the brain. This was the first time acute changes in O-GlcNAcylation of neuronal proteins were shown to directly change synaptic function. Since neural excitability in the hippocampus is a crucial feature of seizures and epilepsy, they hypothesized that acutely increasing protein O-GlcNAcylation might dampen the pathological hyperexcitability associated with these brain disorders.
That turned out to be the case, as reported in the Journal of Neuroscience study, “Acute increases in protein O-GlcNAcylation dampen epileptiform activity in the hippocampus.” The study was led by corresponding author McMahon and first author Luke Stewart, a doctoral student in the Neuroscience Theme of the Graduate Biomedical Sciences Program. Stewart is co-mentored by McMahon and Chatham. “Our findings support the conclusion that protein O-GlcNAcylation is a regulator of neuronal excitability, and it represents a promising target for further research on seizure disorder therapeutics,” they wrote in their research significance statement. The researchers caution that the mechanism underlying the dampening is likely to be complicated.
Glucose, the primary fuel for neurons, also controls the levels of protein O-GlcNAcylation on proteins. However, high levels of the dietary supplement glucosamine, or an inhibitor of the enzyme that removes O-GlcNAcylation, leads to rapid increases in O-GlcNAc levels. In experiments with hippocampal brain slices treated to induce stable and ongoing hyperexcitability, UAB researchers found that an acute rise in protein O-GlcNAcylation significantly decreased the sudden bursts of electrical activity known as epileptiform activity in area CA1 of the hippocampus. An increased protein O-GlcNAcylation in normal cells also protected against a later induction of drug-induced hyperexcitability.
The effects were seen in slices treated with both glucosamine and an inhibitor of the enzyme that removes O-GlcNAc groups. They also found that treatment with glucosamine alone for as short a time as 10 minutes was able to dampen ongoing drug-induced hyperexcitability. In common with the long-term synaptic depression provoked by increased O-GlcNAcylation, the dampening of hyperexcitability required the GluA2 subunit of the AMPA receptor, which is a glutamate-gated ion channel responsible for fast synaptic transmission in the brain. This finding suggested a conserved mechanism for the two changes provoked by increased O-GlcNAcylation — synaptic depression and dampening of hyperexcitability.
The researchers also found that the spontaneous firing of pyramidal neurons in another region of hippocampus, area CA3, was reduced by increased O-GlcNAcylation in normal brain slices and in slices with drug-induced hyperexcitability. This reduction in spontaneous firing of CA3 pyramidal neurons likely contributes to decreased hyperexcitability in area CA1 since the CA3 neurons directly excite those in CA1. Similar to the findings for brain slices, mice that were treated to increase O-GlcNAcylation before getting drug-induced hyperexcitability had fewer of the brain activity spikes associated with epilepsy that are called interictal spikes. Several drug-induced hyperexcitable mice had convulsive seizures during the experiments, this occurred in both the increased O-GlcNAcylation mice and the control mice. Brain activity during the seizures differed between these two groups: The peak power of the brain activity for the mice with increased O-GlcNAcylation occurred at a lower frequency, as compared with the control mice.
*I am very proud to say UA (though UA Tuscaloosa) is my graduate program home!
Adapted from: Luke T. Stewart, Anas U. Khan, Kai Wang, Diana Pizarro, Sandipan Pati, Susan C. Buckingham, Michelle L. Olsen, John C. Chatham, Lori L. McMahon. Acute Increases in Protein O-GlcNAcylation Dampen Epileptiform Activity in Hippocampus. The Journal of Neuroscience, 2017; 37 (34): 8207 DOI: 10.1523/JNEUROSCI.0173-16.2017
Nutrition Daily Nugget…..and a bit of wine!
Watch out for added sugars! They add extra calories but no helpful nutrients. Sugar-sweetened beverages and soft drinks are the number one source of added sugars for most of us.
AND….if you are looking for some excellent wine selections, check out Bright Cellars. The link is also on the right side of my blog for future reference.
If you have kids in your life, you’re probably already aware that body image challenges start early. Numerous studies have shown that even elementary school children, especially girls, believe they need to change something about their body, whether it’s their weight, their hair, their freckles, or something else. It can be heartbreaking to watch the children we care about struggling with these issues, and so many grown-ups want to know what they can do to help. As it turns out, there IS one thing that we, as adults, can do to create an environment that truly supports our kids’ development of a healthy, positive body image. It’s something we actually have a lot of control over, and best of all, when we start doing this, it will immediately make our own lives better, too.
I would like to share my thoughts on the best way to help children with their weight and their body image. Though I do not have credentials behind my name….yet (another six months and I will!), I have struggled with anorexia nervosa for almost 20 years. I have been in recovery for four years so I give myself a bit of credibility when it comes to this subject. I also do a ton of research!
We live in a time when so many people, young and old, are experiencing an epidemic of body hate and body dissatisfaction. You can read the statistics. Nine out of 10 women polled are hitting on their bodies, and 40% of girls, three to six years old, are already dieting. They’re hating on their body. They’re wanting to change their body parts.
This is crazy! This is the kind of challenge that cuts me to the core….and I hope yours as well.
Hating our body, judging it, and believing that it’s unlovable in some way is the royal road to misery and an unhappy life.
Think about it. When we’re born into this world, watch a baby. They’re not sitting there worried about how they’re looking or running around naked or if they’ve got little bits of body fat here and there. Babies and infants are in love with their physiology. It’s just all one. It’s pleasure. It’s play. However, so many people are struggling in silence with self-defeating thoughts about their own physical form. We’ve got to change that.
An unhappy and unresolved body image keeps us small in our sense of self. It limits our personal growth. It stops our best creativity, and it leaves us far short of the beautiful potential that we are born with. Body hate shuts down the soul. It ruins us. It’s a soul crusher!
If you’re a parent or you have kids in your life and you really want to help the child, especially if you’re a parent, then you want to give them the best chance of a loving relationship with their body….OR at least I hope you do! An unhappy body image these days often starts at a young age. However, there is one strategy that will help you succeed in such a brilliant and beautiful way:
Heal your own relationship with your body!
That’s it. Work on you. Work on your relationship with your body. Get to a place, please, as fast as you can where you forgive your own imperfections and where you let go of your own self-criticism. Stop the fight. Just stop the war because your children, our children pick up on who we are. Children are brilliant observers. They’re not good interpreters, but they’re brilliant observers. They will observe mommy, daddy hating on their own body. They’ll feel it. They’ll absorb it through the airwaves.
In a way, this is the beauty of our young ones. They want to be like us, and they will be like us. Therefore, it is best to look in the mirror and start to work on SELF. It is going to save your kids so much heartache and unnecessary waste of life energy as they get older.
SO AGAIN!!…….the greatest gift you can give your kids is to do your own work and do it now and stop the nonsense in your own head! Here’s how you start: Call a cease-fire on self-attack, and mean it! Just wake up and say cease-fire! Consciously choose to begin to love yourself in small ways. It’s a practice. You’ve got to practice every day.
Every day practice gratitude in some way, shape, or form, for the body that you’ve been given. I know you’ve got complaints about it and this and that and all that. However, balance out all those crazy complaints with some gratitude. Find ways every day to affirm love for your body.
Honestly, it is as simple as that because when you do work on yourself, you save future generations from pain and suffering. However, I know for some…..it isn’t that simple. Your “leading by example” will uplift them in ways that they’ll never know, and when you do that, when you do your work on self so your kids don’t have to finish up that work, we create such a better planet and such a better environment for all of us to thrive in. This is the magic of the world!
A new study demonstrated that people of normal weight tend to associate natural foods, such as apples with their sensory characteristics, such as sweetness or softness. On the other hand, processed foods, such as pizzas are generally associated with their function or the context in which they are eaten, such as parties or picnics. “It can be considered an instance of ’embodiment’ in which our brain interacts with our body.” This is the comment made by Raffaella Rumiati, neuroscientist at the International School for Advanced Studies — SISSA in Trieste, on the results of research carried out by her group which reveals that the way we process different foods changes in accordance with our body mass index. The studies included two behavioral and electroencephalographic experiments
“The results are in line with the theory according to which sensory characteristics and the functions of items are processed differently by the brain,” comments Giulio Pergola, the work’s primary author. “They represent an important step forward in our understanding of the mechanisms at the basis of the assessments we make of food.” But that’s not all. Recently published in the Biological Psychology journal, the research also highlighted the ways in which underweight people pay greater attention to natural foods and overweight people to processed foods. Even when subjected to the same stimuli, these two groups show different electroencephalography signals. These results show once again the importance of cognitive neuroscience in the understanding of extremely topical clinical fields, such as dietary disorders.
Adapted from: Scuola Internazionale Superiore di Studi Avanzati. (2017, September 22). Our weight tells how we assess food: A new study reveals that our body mass index interacts with our appreciation of food characteristics. ScienceDaily. Retrieved December 15, 2017 from http://www.sciencedaily.com/releases/2017/09/170922111714.htm
Nutrition Tip of the Day
Share a meal! Try ordering your own appetizer but split the main dish with a friend.
The breast milk of mothers with premature babies have different amounts of microRNA than that of mothers with babies born at term, which may help premature babies catch up in growth and development, according to researchers. In a study, researchers compared the breast milk of mothers with babies born prematurely between 28 and 37 weeks gestation and at term after 38 weeks. They examined whether there were differences in the composition of the breast milks’ microRNAs, snippets of RNA that affect gene expression and can be passed to the infant.
“We found that there are differences in these microRNA profiles, and that the majority of the altered microRNAs influence metabolism,” said Molly Carney, medical student in the Penn State College of Medicine. “If those microRNAs are being transferred to the infant, that could potentially impact how the newborn processes energy and nutrients.” The researchers said the results, recently published in Pediatric Research, could help better match babies with donated breast milk and give insight into how to develop better infant formula.
Babies born prematurely are at risk for a host of problems, including failure to thrive and neurodevelopmental delays. They also tend to be born at a lower weight than term infants. Because of these issues, premature babies have different nutritional needs than babies born at term.
Previous research has established that the macronutrients, fats, sugars (carbohydrates) and proteins, in the breast milk of mothers with premature babies are customized to meet the unique needs of these infants. However, although researchers have suspected that microRNAs in breast milk have a role in infant health and development, no study has specifically looked at whether microRNAs differed between premature and term breast milk. The researchers collected 36 samples of breast milk from mothers with infants born at term and 31 samples from mothers with infants born prematurely. They then processed the samples in a lab, extracted the microRNAs and compared them to the human genome to pinpoint the differences between premature and term breast milk.
After the analysis, the researchers identified nine microRNAs that were significantly different in the premature breast milk. They found that these microRNAs target metabolic processes and may help regulate gastrointestinal function and energy use in premature babies. Steven Hicks, assistant professor of pediatrics in the Penn State College of Medicine, said the results may help explain why premature infants tend to do better when breast-fed by their mothers.
“We know that babies born prematurely have better health outcomes with breast milk than with formula, and our results may explain some of these health benefits associated with breast-feeding,” Hicks said. “The unique microRNA profiles that we found in premature breast milk seem well suited to premature infants, because they target metabolic pathways that could spark catch-up growth.” For example, microRNAs found in premature breast milk block both ADRB3 and NR3C1 gene expression, both of which negatively affect adipogenesis, or fat storage. Blocking these pathways could help boost fat production in premature babies that are having difficulties gaining weight.
Hicks said the results could have several applications, including matching babies with donated breast milk. “For a variety of reasons, babies who are born preterm often rely on donated breast milk,” Hicks said. “Oftentimes, that milk comes from a mother who gave birth at term, and has been breast-feeding for months. That milk may not be optimal for a 32-week premature infant who was born two days ago.”
Hicks also said the findings could lead to opportunities to create better baby formula in the future. “MicroRNAs are an epigenetic material that is made by our bodies and is not present in formula. So even though formula is made to mirror the nutritional components of breast milk — carbohydrates, lipids and proteins — it doesn’t have any of these epigenetic factors,” Hicks said. “It is possible to create microRNAs in a lab and put them in formula. This approach might help bridge the health gap we see between formula- and breast-fed infants.” The researchers said the study helps reinforce that breast milk has multiple nutritional benefits, and may be adapted to individual infant’s needs.
Have a vegetable at breakfast! Most people save their veggies for dinner, but it’s perfectly healthy to think outside the cereal bowl and veg out at breakfast, with veggies. For example, add a sliced tomato to your cheese sandwich or some mushrooms to your eggs.
Something as simple as a feces sample reveals whether you can lose weight by following dietary recommendations characterized by a high content of fruit, vegetables, fibers and whole grains. This is a finding of a new study conducted at the Department of Nutrition, Exercise and Sports at the University of Copenhagen, Denmark. The bacteria we all have in our gut may play a decisive role in personalized nutrition and the development of obesity. This is shown by several studies that have delved into the significance of these bacteria.
“Human intestinal bacteria have been linked to the increasing prevalence of overweight and obesity, and scientists have started to investigate whether the intestinal bacteria can play a role in the treatment of overweight. But it is only now that we have a breakthrough demonstrating that certain bacterial species play a decisive role in weight regulation and weight loss” says Professor Arne Astrup, Head of the Department of Nutrition, Exercise and Sports at the University of Copenhagen, Denmark.
The ratio between the two groups of intestinal bacteria is crucial
A relationship between two groups of intestinal bacteria is decisive for whether overweight people lose weight on a diet that follows the Danish national dietary recommendations and contains a lot of fruit, vegetables, fiber and whole grains. In the study 31 subjects ate the New Nordic Diet for 26 weeks and lost an average of 3.5 kg, whereas the 23 subjects eating an Average Danish Diet lost an average of 1.7 kg. Therefore, weight loss was on average 1.8 kilos greater in the subjects on the New Nordic Diet.
High proportion of Prevotella bacteria lead to weight loss
When the subjects were divided by their level of intestinal bacteria, it was found that people with a high proportion of Prevotellabacteria in relation to Bacteroides bacteria lost 3.5 kg more in 26 weeks when they ate a diet composed by the New Nordic Diet principles compared to those consuming an Average Danish Diet. Subjects with a low proportion of Prevotella bacteria in relation to Bacteroides did not lose any additional weight on the New Nordic Diet. Overall, approximately 50 percent of the population has a high proportion of Prevotella-bacteria in relation to Bacteroides-bacteria.
“The study shows that only about half of the population will lose weight if they eat in accordance with the Danish national dietary recommendations and eat more fruit, vegetables, fibers and whole grains. The other half of the population doesn’t seem to gain any benefit in weight from this change of diet,” says Assistant Professor Mads Fiil Hjorth at the Department of Nutrition, Exercise and Sports at the University of Copenhagen. He continues: “These people should focus on other diet and physical activity recommendations until a strategy that works especially well for them is identified.”
The researchers emphasize that they have already confirmed the results in two independent studies, so they are certain that these results are credible.
Personalized weight loss guidance
The results show that biomarkers, such as faecal samples, blood samples, or other samples from our body, which says something about our state of health, should play a far greater role in nutritional guidance. Simply because biomarkers allow us to adapt the guidance to the individual. “This is a major step forward in personalized nutritional guidance. Guidance based on this knowledge of intestinal bacteria will most likely be more effective than the “one size fits all” approach that often characterises dietary recommendations and dietary guidance,” says Assistant Professor Mads Fiil Hjorth.
The prevalence of food allergies and intolerances have risen exponentially within the past decade. Emerging research indicates that alterations in the intestinal flora may play an important role in the development of these disorders. So, what is the connection between gut micro biome and food allergies and intolerances? Is restoring the micro biome beneficial for treating these conditions? Lets find out! But first….
What are food allergies and intolerances?
Food allergy is defined as an immune response to a food that occurs reproducibly on exposure and generates adverse health effects. Food allergies may be IgE-, non-IgE-, or IgG-mediated. IgE-mediated food allergies occur when the immune system produces IgE antibodies to foods; the antibodies bind to mast cells and basophils, stimulating the release of proinflammatory cytokines that induce an acute, and sometimes life-threatening, allergic response. Non-IgE-mediated food allergies involve components of the immune system other than IgE and can take up to several days to manifest; the symptoms are usually isolated to the GI tract. While still controversial, there is evidence to suggest that food allergies can also be IgG-mediated; this type of allergy causes a delayed hypersensitivity to foods.
Probiotics for food allergies and intolerances
Food intolerances, on the other hand, are non-immunological reactions to food. These reactions are typically associated with enzymatic deficiencies, malabsorption, or sensitivity to certain food components such as gluten or histamine. They can cause a wide variety of gastrointestinal and inflammatory symptoms. Both food allergies and food intolerances significantly decrease quality of life. They take a toll on physical health, diminish the pleasure of eating, and provoke a state of hypervigilance about potential allergens lurking in food.
Food allergies and intolerances are on the rise
Nowadays, allergy-friendly aisles have become commonplace in grocery stores, and many schools and restaurants offer dietary accommodations for individuals with food allergies and intolerances. However, food allergies and intolerances have not always been such a big concern. In fact, it is only within the past decade that the prevalence of these conditions have skyrocketed. Between 1997 and 2011, IgE-mediated food allergies increased by 50% in American children. In addition, research has found that more than 20% of the population of industrialized countries, including the United States, United Kingdom, Australia, and China, suffer from food allergies or intolerances.
Despite the dramatic rise in food allergies and intolerances, few treatment options are available. Conventional medicine advises patients to strictly avoid their trigger foods and to have epinephrine on hand for accidental exposures. However, neither of these strategies addresses the underlying cause of food allergy and intolerance. Novel treatment approaches are desperately needed. An emerging body of research indicates that alterations in the normal human gut flora play a role in the development of food allergies and intolerances. Modulation of the gut microbiota may alleviate food allergies and intolerances and potentially restore tolerance to triggering foods.
The hygiene hypothesis
The average human body contains an astonishing quantity of bacteria—nearly 40 trillion bacterial cells, to be exact! Humans evolved alongside these bacteria, and their presence within our bodies is crucial for our health. This concept has been elucidated in the “hygiene hypothesis.” The hygiene hypothesis states that a lack of early childhood exposure to microbes increases susceptibility to allergic disease by altering the intestinal microbiota and suppressing the normal development of the immune system. Lifestyle factors that reduce microbial exposure early in life deprive the immune system of the stimulation it needs to prevent allergic disease. Factors that reduce microbial exposure include:
In industrialized countries, infants and children often receive multiple courses of antibiotics early in life; this has a significant effect on immunity and may increase their risk of developing food allergies. Maternal use of antibiotics before and during pregnancy also results in microbiome disruption and increases childhood risk of food allergies. In addition, the widespread use of pharmaceuticals in agriculture has led to the presence of antibiotic residues in meat, dairy, and eggs. The consumption of residues in these foods may lead to chronic microbiome disruption.
Exposure to certain synthetic chemicals disrupts the human microbiome. Triclosan, a synthetic antibacterial substance, and parabens, a common preservative used in body products, have been linked to sensitization to food allergens.
A SAD diet
Consumption of a Standard American Diet (SAD), high in refined carbohydrates and depleted of important nutrients, has been linked to an increased risk of food allergies and intolerances. The relationship between diet and allergic disease risk appears to begin early in life; research has discovered that infants who eat a diet high in vegetables, fruits, and home-prepared foods during their first year of life have a reduced incidence of allergic disease compared to infants who consume fewer of these foods.
Vaccination programs have resulted in a decreased exposure to infectious microbes. However, research suggests that this has deprived our immune systems of the immunoregulatory stimulation necessary for establishing protection against allergic disease. Indeed, a rise in allergic disease has been noted with increasing prevalence of vaccination.
Infants born via C-section do not pick up commensal microbes such as Lactobacilli and Bifidobacteria in the birth canal, and are therefore at an increased risk of developing allergic disease during childhood.
Breastfeeding plays a significant role in the establishment of gut flora and immunity in infants; formula feeding, rather than breastfeeding, alters this process and has been associated with an increased risk of allergic disease.
Time spent indoors
Most people in industrialized societies spend a significant portion of their lives indoors. Research suggests that our disconnect with nature reduces the bacterial diversity of the human microbiome and is associated with an increased prevalence of allergic disease.
Alterations in gut flora, food allergies, and food intolerance
Notable differences have been observed in the gut flora between food-allergic and nonallergic individuals, suggesting that alterations in the normal human gut flora play an important role in the pathogenesis of food allergies and intolerances. The normal human microbiome is composed of a diverse array of bacteria, including Bacteroides, Enterobacteria, Bifidobacteria, and Lactobacilli. These commensal bacteria interact with the mucosal immune system of the gut to promote immune tolerance of foods. Lifestyle factors that decrease numbers of beneficial gut microbes can impair immune tolerance, resulting in allergic sensitization or intolerance to foods.
Alterations in specific types of gut bacteria have been linked to the development of food allergies. Most of the studies examining this phenomenon have been conducted in infants and children. In children, decreased Lactobacilli and increased Staphylococcus aureus are associated with egg and milk allergies. Children with decreased levels of L. rhamnosus, L. casei, L. paracasei, and Bifidobacterium adolescentis during their first two months of life were found to be at a higher risk of developing allergic sensitization to cow’s milk, egg white, and inhalant allergens. Reduced Bacteroides, Proteobacteria, and Actinobacteria are also associated with food allergen sensitization in infants.
In addition to increasing the risk of food allergies, a lack of microbiome diversity may predispose to non-immunologic food intolerances such as gluten, FODMAP, and histamine intolerance. Certain species of bacteria assist in the breakdown of gluten proteins, and a lack of these may predispose to gluten intolerance. Bacterial overgrowth of the small intestine is a common cause of FODMAP intolerance. Histamine intolerance may occur when there is an overgrowth of bacteria that produce histamine or that make enzymes that interfere with the metabolism of histamine. Gut bacteria and food allergies: what do they have in common?
Probiotics for food allergies and intolerances
The therapeutic use of probiotics could truly be a breakthrough in the prevention and treatment of food allergies and intolerances. Prenatal supplementation with Bifidobacterium bifidum, B. lactis, Lactobacillus acidophilus, and Lactobacillus rhamnosus has been found to prevent food allergy-induced atopic sensitization in infants with a familial predisposition to food allergies. Administration of L.salivarius, L. paracasei, Bifidobacterium animalis, and Bifidobacterium bifidum to pregnant women and to their infants significantly reduced the incidence of atopic sensitization to common food allergens in the infants.
Probiotic supplementation may also decrease atopic sensitization, and potentially reverse sensitization, postnatally. In infants with an allergy to cow’s milk, supplementation with Lactobacillus rhamnosus promoted the acquisition of tolerance to milk proteins and reversed sensitization. In older children with cow’s milk allergy, L. rhamnosus enhanced the production of IL-10, an anti-inflammatory cytokine, and alleviated allergic symptoms. A meta-analysis of studies found that early-life supplementation with Lactobacillus and Bifidobacterium strains reduced the risk of atopic sensitization in children; however, it found that L. acidophilus increased the risk of sensitization. Inconsistent findings such as this could be related to variations in probiotic dosing or duration of treatment. It is important to note that most of the studies assessing the efficacy of probiotics for the treatment of food allergies have been conducted prenatally, in infants, and in children. The gut microbiome in early life differs from that in adulthood, in that the probiotic interventions mentioned in the blog may be more beneficial for the prevention and reversal of food allergies in young children, rather than in adults. More research is needed to determine whether probiotic supplementation can alleviate food allergies in adults.
In addition to preventing and reversing food allergies in children, probiotics may also be beneficial for treating food intolerance. Supplementation with a multi-strain probiotic that included Lactobacilli, Bacillus coagulans, and Saccharomyces boulardii significantly reduced symptoms in patients with non-celiac gluten sensitivity. Probiotics such as Bacillus coagulans and L. acidophilus may alleviate small intestinal bacterial overgrowth (SIBO), a condition associated with FODMAP intolerance. Finally, while research is not yet conclusive, it has been suggested that an overgrowth of histamine-producing bacteria in the gut may contribute to histamine intolerance. The avoidance of probiotic strains that produce histamine and consumption of strains that degrade histamine may therefore be helpful for relieving or alleviating histamine intolerance. Histamine-producing strains include L. reuteri, L. casei, and L. bulgaricus. Histamine-degrading strains include L. rhamnosus, L. plantarum, and Bifidobacteria. Whereas probiotic treatment for food allergies appears to be beneficial primarily for infants and children, the benefits of probiotics for food intolerances can be extended to adults.
Mechanisms of action of probiotics
There are several mechanisms by which probiotics alleviate food allergies and intolerances. Probiotics upregulate commensal gut microbes, the bacteria normally present in the gut that are responsible for interacting with the immune system to promote tolerance of foods. Probiotics also reduce intestinal permeability, therefore, decreasing antigen uptake from the intestinal lumen; this phenomenon is the first step in food allergen sensitization. Allergic disorders are associated with increased activity of the Th2 branch of the immune system. Probiotics modulate the immune system in such a way that it instead favors the Th1 response, an immune response associated with resolution of allergic symptoms. In addition, probiotics increase intestinal IgA, an immunoglobulin associated with immune tolerance and a reduced risk of IgE-mediated allergic diseases. Finally, probiotics may reduce food intolerances by crowding out pathogenic bacteria and reducing intestinal inflammation.
Prebiotics potentiate the action of probiotics by promoting their proliferation in the intestine. Several studies have found an association between supplementation with prebiotic oligosaccharides and a reduced incidence of allergic disease.
Eat a whole-foods diet
A whole-foods, nutrient-dense diet may offer additional protection against food allergies and intolerances. Consumption of omega-3 fatty acids; vitamins C, E, and A; beta-carotene; and zinc are associated with a decreased incidence of food allergies. Conversely, a diet high in refined carbohydrates, artificial sweeteners, gluten, omega-6 fatty acids, and food additives may predispose to food allergies and intolerances. While the evidence is not conclusive, the consumption of genetically modified foods may also contribute to food allergies and intolerances, due to the potential allergenicity of the technologically altered proteins in these foods.
In Summary (for those who have food-allergy and intolerances)
Choose foods that are nutrient-dense, contain probiotics, and are fermented
Take caution with antibiotics
Read labels on body care products, and avoid ones that contain triclosan and parabens
Spend time with nature, where beneficial microbes are abundant
Make Time to Eat with Those You Love! I hope you, just as I, value family meal times with loved ones. Our children’s schedule, as well as our own, is often hectic but make a point to eat breakfast each morning together with the kids. The family bonding time allows you to ask about their day. It also ensures they leave for school with their bellies filled from a nutritious breakfast and a smile on their face.