Allergic responses to food have risen by as much as 20% in developed countries in the last 10 years.1 One of the most common food allergies in infants and children is cow’s milk allergy. Suggested causative factors include excessive antibiotic use, reduced exposure to infectious disease, poor dietary choices including high-fat and low-fibre diets, caesarean birth and formula feeding.1 All of these factors may negatively impact the beneficial interactions that have developed as part of our co-evolution with bacteria and which have helped the composition of our commensal microbiota. Dysbiosis is the result - this has a high incidence of predisposing genetically susceptible people to allergic disease.1
A study looked at the use of Lactobacillus rhamnosus GG, supplemented at 45-85million Colony Forming Units (CFU) per day mixed into a formula that contained a hydrolysed form of the cow’s milk protein casein, for 52 weeks. The control was a group of infants, fed the formula without Lactobacillus rhamnosus GG. The participants were infants aged 1-12months with a suspected IgE-mediated cow’s milk allergy. Stool samples were collected both before and after the treatment. All of the participants with the cow’s milk allergy had significantly reduced Bifidobacteriaceae, Streptococcaceae, Enterobacteriaceae and Enterococcaceae, and much higher levels of Ruminococcaceae and Lachnospiraceae when compared with healthy controls.1
Interestingly, five of the 12 (42%) treated with Lactobacillus rhamnosus GG developed a tolerance to cow’s milk, while all participants (100%) in the formula-only group remained allergic. At a strain-level, those who became tolerant has significantly higher levels of butyrate-producing Oscillospira.1 The treatment group also showed higher butyrate levels compared to those who remained allergic. The results showing elevated levels of butyrate after treatment of Lacobacillus rhamnosus GG also had a larger enrichment of Blautia (involved in microbiota maturation in children) and butyrate-producing Roseburia. This led the authors to conclude that tolerance may be associated with the acquisition of specific strains within these genera.1
The mechanism behind the role of Lactobacillus rhamnosus GG in relation to cow’s milk allergy is believed to be via modulation of cytokines that influence gut permeability and, as a flow on effect, reduction of the immune system’s exposure to dietary allergens.1 Lactobacillus rhamnosus GG is also involved in the enrichment of bacterial strains involved in the production of butyrate, a short chain fatty acid that is the preferred energy source for colonocytes and a marker of intestinal health.
- Berni Canani R, Sangwan N, Stefka AT, et al. Lactobacillus rhamnosus GG-supplemented formula expands butyrate-producing bacterial strains in food allergic infants. ISME J. 2016;10(3):742-750. doi:10.1038/ismej.2015.151.