Summary: Researchers report infants who are allergic to cow milk have a different composition of gut microbes than those who are not allergic to the milk. Transplanting gut microbes from those with no allergies helped to protect against potentially life threatening reactions. The study suggests gut microbes impact the host’s immune system and play a critical role in regulating allergic responses to food.
New research suggests that the gut microbiome may help prevent the development of cow’s milk allergy. Scientists at the University of Chicago found that gut microbes from healthy human infant donors transplanted into mice protected animals exposed to milk from experiencing allergic reactions, while gut microbes transplanted from infants allergic to milk did not. The work, described online today in Nature Medicine, was supported in part by NIH’s National Institute of Allergy and Infectious Diseases. The findings may inform research to develop microbiome-based therapies to prevent or treat food allergy.
Scientists previously found that infants allergic to cow’s milk had different compositions of gut microbes than non-allergic infants. Previous studies also revealed that some microbes are associated with a lower risk of developing food allergy, leading researchers to examine whether gut microbes of infants without milk allergy might be protective.
Researchers transplanted gut microbes from each of eight infant donors into groups of mice raised in a sterile environment and sensitized to milk protein–meaning the animals’ immune systems created allergic antibodies to milk. When later exposed to milk, mice receiving no microbes or microbes from milk-allergic children produced allergic antibodies and experienced anaphylaxis, a potentially life-threatening allergic reaction. Mice receiving gut microbes from non-allergic infants had no reactions.
Investigators then analyzed microbes in infant stool samples, finding many differences between the stool of infants who were allergic to milk and those who were not. Mice transplanted with microbes from non-allergic infants also harbored a family of microbes previously found to protect against developing food allergies. Further experiments identified one microbe, Anaerostipes caccae, that prevented the development of milk allergy when transplanted alone into groups of mice. Researchers then sampled cells along the mice’s gut linings–where food allergies in mice and humans begin to develop. They found that mice that received microbes from non-allergic infants expressed different genes compared to those that did not, suggesting that microbes residing in the gut impact the host’s immune system. The researchers conclude that intestinal microbes play a critical role in regulating allergic responses to food and suggest that further research could lead to microbiome-modifying therapies to prevent or treat food allergy.
About this neuroscience research article
Funding: The work was supported by NIH/National Institute of Allergy and Infectious Diseases.
Source: Judith Lavelle – NIH/NIAID Publisher: Organized by NeuroscienceNews.com. Image Source: NeuroscienceNews.com image is credited to The University of Chicago. Original Research:Abstract for “Healthy infants harbor intestinal bacteria that protect against food allergy” by Taylor Feehley, Catherine H. Plunkett, Riyue Bao, Sung Min Choi Hong, Elliot Culleen, Pedro Belda-Ferre, Evelyn Campbell, Rosita Aitoro, Rita Nocerino, Lorella Paparo, Jorge Andrade, Dionysios A. Antonopoulos, Roberto Berni Canani & Cathryn R. Nagler in Nature Medicine. Published January 14 2019. doi:10.1038/s41591-018-0324-z
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[cbtabs][cbtab title=”MLA”]NIH/NIAID”Gut Microbes From Healthy Infants Block Milk Allergy Development: Mouse Study.” NeuroscienceNews. NeuroscienceNews, 14 January 2019. <https://neurosciencenews.com/microbiome-milk-allergy-10527/>.[/cbtab][cbtab title=”APA”]NIH/NIAID(2019, January 14). Gut Microbes From Healthy Infants Block Milk Allergy Development: Mouse Study. NeuroscienceNews. Retrieved January 14, 2019 from https://neurosciencenews.com/microbiome-milk-allergy-10527/[/cbtab][cbtab title=”Chicago”]NIH/NIAID”Gut Microbes From Healthy Infants Block Milk Allergy Development: Mouse Study.” https://neurosciencenews.com/microbiome-milk-allergy-10527/ (accessed January 14, 2019).[/cbtab][/cbtabs]
Healthy infants harbor intestinal bacteria that protect against food allergyy
There has been a striking generational increase in life-threatening food allergies in Westernized societies1,2. One hypothesis to explain this rising prevalence is that twenty-first century lifestyle practices, including misuse of antibiotics, dietary changes, and higher rates of Caesarean birth and formula feeding have altered intestinal bacterial communities; early-life alterations may be particularly detrimental3,4. To better understand how commensal bacteria regulate food allergy in humans, we colonized germ-free mice with feces from healthy or cow’s milk allergic (CMA) infants5. We found that germ-free mice colonized with bacteria from healthy, but not CMA, infants were protected against anaphylactic responses to a cow’s milk allergen. Differences in bacterial composition separated the healthy and CMA populations in both the human donors and the colonized mice. Healthy and CMA colonized mice also exhibited unique transciptome signatures in the ileal epithelium. Correlation of ileal bacteria with genes upregulated in the ileum of healthy or CMA colonized mice identified a clostridial species, Anaerostipes caccae, that protected against an allergic response to food. Our findings demonstrate that intestinal bacteria are critical for regulating allergic responses to dietary antigens and suggest that interventions that modulate bacterial communities may be therapeutically relevant for food allergy.