Detection and quantification ofBifidobacterium lactisLAFTI^�B94 in human faecal samples from a consumption trial

Abstract

A method was developed to allow detection of the probiotic Bifidobacterium lactis LAFTI B94 in human clinical samples. A new probe, Laf94p, was developed to accomplish colony hybridization of B. lactis B94. PCR detection of B94 was also achieved using the species-specific (B. lactis) primer pair. These tests and probes allowed detection and quantification of B94 in the human intestinal flora. The sensitivity of the probe was assessed by monitoring faecal levels of B94 in humans who were fed the culture. In this trial, five volunteers were fed with the probiotic. The presence of B94 was assessed daily. Viable B94 could be detected at high levels (as high as 1.8 x 10(9) cfu g(-1) wet weight) during the feeding period. Four weeks after the feeding stopped, B94 could still be detected in one subject. These results indicate that B94 survives in the human gastrointestinal tract.

Effect of a Synbiotic Yogurt on Levels of Fecal Bifidobacteria, Clostridia, and Enterobacteria

“…The rapid disappearance of Bb-12 from fecal samples following cessation of feeding is consistent with other published clinical studies (7,22). Some studies have seen persistence in one or two subjects for a week or two longer (42). However, this may have been due to variations in subject reliability or to inadvertent consumption of other foods containing bifidobacteria rather than persistence of the species.…”

Genomic Insights into Bifidobacteria

“…The prolonged exposure of this subspecies to dairy fermentation environments is further supported by the reduced size of the genomes of this subspecies, which is a phenomenon that has been found to occur in organisms that are in less-complex environments where fewer features are needed to be successful, such as the genome reduction of Buchnera aphidicola, which is predicted to be due to environmental changes (230). This may explain the inability of these bacteria to persist in the intestines of human subjects, as they have been observed to disappear rapidly after stoppage of eating foods containing these bacteria (88,215,300,319).…”

Multi-Loci Gene Sequencing and Identification of Bifidobacteria Strains Isolated from Dairy and Pharmaceutical Sources in South Africa

“…Bifidobacterium animalis subsp. lactis Bb12 (Lake Foods, SA) was used as a reference strain because it has been a commercial strain for over 25 years and is cited in more than 200 scientific publications (Su et al, 2005;Barrangou et al, 2009;Buruleanu et al, 2012).…”

“…The MLSA approach is one of the best techniques that can be used for the phylogenetic analysis of strains of closely related species (Delétoile et al, 2010). Accuracy in probiotic strain identification is imperative during probiotic food product development as well as in clinical trials (Su et al, 2005). The MLSA approach was also applied in the present study because the precisely identified strains were intended to be included in a probiotic fermented maize beverage, in later work.…”

“…animalis subsp. lactis may be the most used Bifidobacterium strain in marketed probiotic dairy products (Su et al, 2005;Collado et al, 2006;Barrangou et al, 2009), perhaps due to technological reasons. Bifidobacterium lactis for example tolerates oxygen better than Bf.…”