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Bifidobacteria strains isolated from stools of iron deficient infants can efficiently sequester iron.

ABSTRACT: Bifidobacteria is one of the major gut commensal groups found in infants. Their colonization is commonly associated with beneficial effects to the host through mechanisms like niche occupation and nutrient competition against pathogenic bacteria. Iron is an essential element necessary for most microorganisms, including bifidobacteria and efficient competition for this micronutrient is linked to proliferation and persistence. For this research we hypothesized that bifidobacteria in the gut of iron deficient infants can efficiently sequester iron. The aim of the present study was to isolate bifidobacteria in fecal samples of iron deficient Kenyan infants and to characterize siderophore production and iron internalization capacity.Fifty-six bifidobacterial strains were isolated by streaking twenty-eight stool samples from Kenyan infants, in enrichment media. To target strains with high iron sequestration mechanisms, a strong iron chelator 2,2-dipyridyl was supplemented to the agar media. Bifidobacterial isolates were first identified to species level by 16S rRNA sequencing, yielding B. bifidum (19 isolates), B. longum (15), B. breve (11), B. kashiwanohense (7), B. pseudolongum (3) and B. pseudocatenulatum (1). While most isolated bifidobacterial species are commonly encountered in the infantile gut, B. kashiwanohense was not frequently reported in infant feces. Thirty strains from culture collections and 56 isolates were characterized for their siderophore production, tested by the CAS assay. Siderophore activity ranged from 3 to 89% siderophore units, with 35 strains (41%) exhibiting high siderophore activity, and 31 (36%) and 20 (23%) showing intermediate or low activity. The amount of internalized iron of 60 bifidobacteria strains selected for their siderophore activity, was in a broad range from 8 to118 ?M Fe. Four strains, B. pseudolongum PV8-2, B. kashiwanohense PV20-2, B. bifidum PV28-2a and B. longum PV5-1 isolated from infant stool samples were selected for both high siderophore activity and iron internalization.A broad diversity of bifidobacteria were isolated in infant stools using iron limited conditions, with some strains exhibiting high iron sequestration properties. The ability of bifidobacteria to efficiently utilize iron sequestration mechanism such as siderophore production and iron internalization may confer an ecological advantage and be the basis for enhanced competition against enteropathogens.

SUBMITTER: Vazquez-Gutierrez P

PROVIDER: S-EPMC4320568 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature

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Bifidobacteria strains isolated from stools of iron deficient infants can efficiently sequester iron.

Vazquez-Gutierrez Pamela P Lacroix Christophe C Jaeggi Tanja T Zeder Christophe C Zimmerman Michael Bruce MB Chassard Christophe C

BMC microbiology 20150116

<h4>Background</h4>Bifidobacteria is one of the major gut commensal groups found in infants. Their colonization is commonly associated with beneficial effects to the host through mechanisms like niche occupation and nutrient competition against pathogenic bacteria. Iron is an essential element necessary for most microorganisms, including bifidobacteria and efficient competition for this micronutrient is linked to proliferation and persistence. For this research we hypothesized that bifidobacteri ...[more]

PMID: 25591860

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Project description:Iron-deficiency anemia (IDA) is associated with alterations in infant behavior and development that may not be corrected with iron therapy.To determine if a home-based intervention to foster child development improves behavior and development of infants with IDA.Infants with IDA and nonanemic infants aged 6 and 12 months were treated with oral iron and randomly assigned to a year of surveillance or intervention. Infants in the surveillance group were visited weekly, and information on iron intake, feeding, and health were recorded. Infants in the intervention were visited weekly, and the home visits included an hour-long program to foster child development by providing support to the mother-infant relationship. The number of infants enrolled was 128 (66 who received intervention) and 149 (70 intervention) at 6 and 12 months, respectively. Psychologists who were unaware of iron status and intervention assignment assessed infants' cognitive, motor, and social-emotional development (Bayley Scales) at the beginning, midpoint, and end of the year; 116 6-month-olds and 134 12-month-olds had at least 2 assessments. Hierarchical linear modeling was used to analyze change over time.Infants with IDA, regardless of enrollment age, were rated as less positive in social-emotional behavior at baseline. There were significant interactions between iron status and intervention associated with change in cognitive performance and positive social-emotional behavior. Infants with IDA who received intervention had developmental trajectories comparable to those of nonanemic infants in the intervention and surveillance groups, but these infants did not catch up in social-emotional behavior. Infants with IDA who received surveillance showed less increase in cognitive scores and had declines in positive social-emotional ratings.Home-based intervention to foster child development improved cognitive and social-emotional scores in infants with IDA, but social-emotional differences remained between infants with IDA and those without IDA.

Project description:BackgroundIron therapy induces inflammation, which could decrease iron absorption. Increased exposure of iron in the gut could also alter microbiome file. Providing antioxidants such as vitamin E with iron therapy has been associated with reduced oxidative potential.ObjectiveThe aim of the present study was to test the efficacy of adding vitamin E to therapeutic iron therapy on iron repletion, inflammation markers, and gut microbiome in iron-deficient infants and toddlers.DesignThis was a randomized, double-blind, control trial in which infants and toddlers (Denver, CO metro area) who were at risk of iron deficiency were screened. Eligible participants were randomized to receive iron therapy (6 mg · kg · day) plus placebo (n = 22) or iron (6 mg · kg · day) and vitamin E (18 mg/day, n = 14) for 8 weeks. Iron and inflammation status, and gut microbiome (16S sequencing) were analyzed in all participants before and after the treatment.ResultsAfter 8 weeks of treatment, average serum ferritin level returned to normal for both iron + placebo and iron + vitamin E groups at 33.3 ± 20.2 and 33.5 ± 21.5 μg/L, respectively. Serum vitamin E concentration increased in iron + vitamin E group. No change over time was observed regarding serum interleukin-4, tumor necrosis factor-α, or fecal calprotectin. The relative abundance of the genus Roseburia (phylum Firmicutes), a butyrate producer, increased in the Fe + E group (Δ1.3%, P < 0.01). Also at the genus level, the genus Escherichia decreased by 1.2% on average among all participants (effect of time P = 0.01).ConclusionsUsing a therapeutic iron dose of 6 mg · kg · day is effective in treating iron deficiency during an 8-week period, without inducing persistent inflammatory response. Changes of the gut microbiome raised the possibility that antioxidant therapy in conjunction with therapeutic iron supplementation could potentially improve microbial community profiles in the intestinal tract.

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Bifidobacteria strains isolated from stools of iron deficient infants can efficiently sequester iron.

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Bifidobacteria strains isolated from stools of iron deficient infants can efficiently sequester iron.

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