The life history ofLactobacillus acidophilusas a probiotic: a tale of revisionary taxonomy, misidentification and commercial success

Abstract

Lactobacillus acidophilus is a commercially significant bacterial probiotic, originally isolated from the human gastrointestinal tract and designated Bacillus acidophilus in 1900. Throughout the development of methods to identify and characterise bacteria, L. acidophilus has undergone multiple taxonomic revisions and is now the type species of a phylogenetic subgroup in the highly diverse and heterogeneous Lactobacillus genus. As a result of the limitations of differentiating phenotypically similar species by morphological and biochemical means and revisionary nature of Lactobacillus taxonomy, the characterisation of L. acidophilus has struggled with misidentification and misrepresentation. In contrast, due to its global use as a probiotic supplement in functional foods, L. acidophilus sensu stricto is now one of the most well-characterised Lactobacillus species. Here, we establish the provenance of L. acidophilus strains, unpicking historical and current misidentifications of L. acidophilus, and reviewing the probiotic, genomic and physiological characteristics of this important Lactobacillus species.

Assessment of potentially probiotic properties of Lactobacillus strains isolated from chickens

“…The capability to tolerate acid and bile is considered as good indicators for the viability in the GIT, thus these characteristics are often assessed in preliminary examination of potentially probiotic strains (Bull et al 2013). …”

Bacteriocin production: a relatively unharnessed probiotic trait?

“…Lactobacillus acidophilus probiotics, several of which are employed for use in commercial products 31, 32 , are somewhat exceptional in this regard in that two such strains, NCFM and LA-5, are known to produce the bacteriocin lactacin B 33, 34 . This bacteriocin has a narrow spectrum of activity, capable of inhibiting other lactobacilli and Enterococcus faecalis 35 .…”

Probiotics for vaginal health in South Africa: what is on retailers’ shelves?

“…Some reasons cited for the use of L. acidophilus strains in probiotic formulations include that it is stable in products, resistant to GIT bile, tolerant to low pH, and adherent to human colonocytes in cell culture [50–53]. In addition, they produce antimicrobial substances and contain lactase activity, meeting the criteria needed for an effective probiotic [54]. Similar characteristics have been described for all the above-mentioned Lactobacillus and Bifidobacterium spp.…”