Interaction of Bifidobacterium bifidum LMG13195 with HT29 Cells Influences Regulatory-T-Cell-Associated Chemokine Receptor Expression

Self Cite

Exopolysaccharides (EPS) are extracellular carbohydrate polymers synthesized by a large variety of bacteria. Their physiological functions have been extensively studied, but many of their roles have not yet been elucidated. We have sequenced the genomes of two isogenic strains of Bifidobacterium animalis subsp. lactis that differ in their EPS-producing phenotype. The original strain displays a nonmucoid appearance, and the mutant derived thereof has acquired a mucoid phenotype. The sequence analysis of their genomes revealed a nonsynonymous mutation in the gene Balat_1410, putatively involved in the elongation of the EPS chain. By comparing a strain from which this gene had been deleted with strains containing the wild-type and mutated genes, we were able to show that each strain displays different cell surface characteristics. The mucoid EPS synthesized by the strain harboring the mutation in Balat_1410 provided higher resistance to gastrointestinal conditions and increased the capability for adhesion to human enterocytes. In addition, the cytokine profiles of human peripheral blood mononuclear cells and ex vivo colon tissues suggest that the mucoid strain could have higher anti-inflammatory activity. Our findings provide relevant data on the function of Balat_1410 and reveal that the mucoid phenotype is able to alter some of the most relevant functional properties of the cells.T he genus Bifidobacterium includes commensal microorganisms commonly found in the human gut. Some strains, belonging mainly to the species Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium bifidum, and Bifidobacterium animalis, have been used as probiotics, since there is scientific evidence that links the administration of these bacteria with specific health benefits (1, 2). In particular, B. animalis subsp. lactis has a robust phenotype that allows growth at high numbers in commercial applications under nonanaerobic conditions. Furthermore, strains of this subspecies survive the gastric passage and reach the intestinal tract in a metabolically active state, being also the most common representatives of bifidobacteria in functional food products (3). Because they are more resistant to harsh environmental conditions, strains of B. animalis subsp. lactis have been studied more than those of other members of the genus Bifidobacterium, and clinical studies demonstrated their healthpromoting attributes in some gastrointestinal disorders and allergic processes (4-6).Exopolysaccharides (EPS) are extracellular layers of carbohydrates typically found in microorganisms (7). EPS production has been involved in a variety of physiological processes that have implications for the producer microorganism and the host (8, 9). Specifically, in intestinal bacteria some of the most relevant roles attributed to EPS are the favoring of intestinal colonization and survival (10-12) and immunomodulation (11,13,14).A common set of functional modules, including the synthesis of activated sugar precursors, cytoplasmic assembly of the EPS unit, export...

Section: Resultsmentioning

confidence: 99%

A Single Mutation in the Gene Responsible for the Mucoid Phenotype of Bifidobacterium animalis subsp. lactis Confers Surface and Functional Characteristics

Hidalgo-Cantabrana

Sánchez

Álvarez‐Martín

et al. 2015

Self Cite

“…It was recently reported that soluble factors secreted after Bifidobacterium bifidum LMG13195 administration interact with intestinal epithelial cells and promote the generation of CD4 ϩ CD25 high lymphocytes expressing chemokine receptor Treg markers that favor mucosal homing, thus making possible their recruitment to the intestinal mucosa (45). This in turn contributes to the increase in the percentage of jejunal and ileal LPL CD3 ϩ CD4 ϩ CD8 Ϫ T cells.…”

Section: Cd4mentioning

confidence: 99%

Dose-Dependent Effects of Lactobacillus rhamnosus on Serum Interleukin-17 Production and Intestinal T-Cell Responses in Pigs Challenged with Escherichia coli

Zhu

Zhang

et al. 2014

“…The strain was selected as a representative of a species that has been reported to possess numerous host interaction properties (9), including marked adhesion to enterocytes (10)(11)(12), immunomodulation (12)(13)(14), and metabolism of mucin and human milk oligosaccharides (15,16).…”

mentioning

confidence: 99%

Consumption of a Bifidobacterium bifidum Strain for 4 Weeks Modulates Dominant Intestinal Bacterial Taxa and Fecal Butyrate in Healthy Adults

Gargari

Taverniti

Balzaretti

et al. 2016

Modulation of the intestinal microbial ecosystem (IME) is a useful target to establish probiotic efficacy in a healthy population. We conducted a randomized, double-blind, crossover, and placebo-controlled intervention study to determine the impact of Bifidobacterium bifidum strain Bb on the IME of adult healthy volunteers of both sexes. High-throughput 16S rRNA gene sequencing was used to characterize the fecal microbiota before and after 4 weeks of daily probiotic cell consumption. The intake of approximately one billion live B. bifidum cells affected the relative abundance of dominant taxa in the fecal microbiota and modulated fecal butyrate levels. Specifically, Prevotellaceae (P ‫؍‬ 0.041) and Prevotella (P ‫؍‬ 0.034) were significantly decreased, whereas Ruminococcaceae (P ‫؍‬ 0.039) and Rikenellaceae (P ‫؍‬ 0.010) were significantly increased. We also observed that the probiotic intervention modulated the fecal concentrations of butyrate in a manner dependent on the initial levels of short-chain fatty acids (SCFAs). In conclusion, our study demonstrates that a single daily administration of Bifidobacterium bifidum strain Bb can significantly modify the IME in healthy (not diseased) adults. These findings demonstrate the need to reassess the notion that probiotics do not influence the complex and stable IME of a healthy individual. IMPORTANCEFoods and supplements claimed to contain health-promoting probiotic microorganisms are everywhere these days and mainly intended for consumption by healthy people. However, it is still debated what actual effects probiotic products may have on the healthy population. In this study, we report the results of an intervention trial aimed at assessing the modifications induced in the intestinal microbial ecosystem of healthy adults from the consumption of a probiotic product. Our results demonstrate that the introduction of a probiotic product in the dietary habits of healthy people may significantly modify dominant taxa of the intestinal microbiota, resulting in the modulation of short-chain fatty acid concentrations in the gut. The overall changes witnessed in the probiotic intervention indicate a mechanism of microbiota modulation that could have potential effects on human health.