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United States Department of Agriculture

Agricultural Research Service


Location: Diet, Genomics and Immunology Laboratory

2012 Annual Report

1a. Objectives (from AD-416):
ARS is interested in determining the impact of health-promoting components in foods including those containing probiotic bacteria. Experimental data generated in our pig model showed that Bifidobacterium lactis (Bb12) can modulate immune function and selectively affect local responses to allergic proteins. The hypothesis is that probiotics can prevent the incidence and severity of allergy in children with high risk of developing atopic diseases. Collaborative studies in children with allergic disease in Baltimore, MD showed that Bifidobacterium spp were reduced when compared to controls. We propose to study a larger population of subjects with atopy and from different environmental conditions (socioeconomic status, age, diet, and ethnic background) to confirm the hypothesis that Bifidobacterium spp (B. animalis, B. infantis, B. cantelatum, B. breve, and B. longum) are needed to maintain intestinal homeostasis and reduce the severity of clinical disease. The project plan has one objective that directly relates to this agreement: 1) To elucidate the mechanisms used by probiotic bacteria to improve respiratory and intestinal mucosal responses to allergens, and correlate intestinal microflora composition of pigs and humans with biomarkers of allergic and intestinal disease. The COOPERATOR is interested in the identification of risk factors for the development of asthma and atopy in children in a tropical region (Cartagena-Colombia). The ultimate goal of both ARS and the COOPERATOR is to develop recommendations for feeding selected probiotics to promote a healthy microflora in the intestine.

1b. Approach (from AD-416):
ARS will acquire processed clinical samples from the COOPERATOR (nucleic acids from blood and fecal samples). This information will be used by both ARS and the COOPERATOR to jointly develop new research studies to study intestinal microbiota homeostasis and improved immune response.

3. Progress Report:
Changes in commensal bacterial species abundance and wheezing were followed for three years in children from a population with high incidence of atopic disease by clinicians in Colombia. A subset of children from low–income families who were delivered normally and breastfed were analyzed. DNA isolated from intestinal microflora were analyzed by molecular techniques to determine the abundance of commensal bacteria species. Bifidobacterium infantis was more abundant in children receiving exclusive breastfeeding during the first trimester, but it was not associated with wheezing. Colonization by Lactobacillus species was significantly reduced in children who exhibited wheezing compared to those who didn’t suggesting that early Lactobacillus colonization may be protective from wheezing in children living in disadvantaged communities in a tropical environment. Data from molecular analysis is being analyzed to establish correlations with clinical signs and parameters associated with atopy.

4. Accomplishments

Last Modified: 2/23/2016
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