Numerical taxonomy of Lactobacillus spp. associated with healthy and diseased mucosa of the human intestines

Abstract

Two-hundred and fifty Lactobacillus strains isolated from healthy and diseased mucosa of human intestines of 75 individuals and 49 reference strains were phenotypically classified using 49 unit characters. Data were processed by the Jaccard (SJ) and Simple Matching (SSM) coefficients, and unweighted pair group algorithm with arithmetic averages. Seventeen major clusters were defined at the 76% SJ-similarity level which approximately correspond to the SSM-level of 91%. Seven clusters could be identified: Lactobacillus plantarum (isolates recovered from 5% of the patients), Lact. casei subsp. rhamnosus (17% of the patients), Lact. casei subsp. pseudoplantarum (5% of the patients), Leuconostoc mesenteroides subsp. mesenteroides (3% of the patients), Lact. buchneri (4% of patients), Lact. reuteri (4% of the patients) and Lact. salivarius subsp. salivarius (9% of the patients). Unassigned clusters 1 and 3 both contained homofermentative Lactobacillus strains. Cluster 1 included the type strains of Lact. crispatus, Lact. acidophilus, Lact. jensenii and Lact. gasseri, and cluster 3, the type strains of Lact. delbrueckii subsp. lactis, Lact. agilis and Lact. casei subsp. tolerans. Clusters 1 and 3 were found in 15% and 25% of the patients, respectively. Unassigned clusters 2, 6, 7, 8 and 10 contained homofermentative Lactobacillus strains but no reference strains. Clusters 11, 12, 15 and 17 were made up of heterofermentative Lactobacillus strains but no reference strains. Phenotypical characteristics of the clusters are given. No obvious trends in species (cluster) composition between different intestinal locations could be noted. Most clusters contained isolates from both diseased and healthy mucosa. Exceptions were cluster 15 and cluster 17 which only included isolates from healthy mucosa, and cluster 11 which only included isolates from diseased mucosa. Cluster 15 was isolated in 12% of the patients, and cluster 11 in 8%.

Host-microbial symbiosis in the vertebrate gastrointestinal tract and the Lactobacillus reuteri paradigm

“…In contrast, the prevalence of L. reuteri is much lower in humans, where the species is only occasionally found (46). For example, Molin et al (47) reported that only 4% of the human subjects harbored L. reuteri on the GIT mucosa. Nevertheless, the type strain of L. reuteri, DSM 20016 T , could be continuously isolated from a human subject over several months, and the species has been considered autochthonous to the human digestive tract (41,48).…”

Lactobacilli from human gastrointestinal mucosa are strong stimulators of IL-12 production

“…Lactobacilli are members of the normal indigenous flora of the oral cavity, small and large intestine, and female genital tract [2,3]. The Lactobacillus species which dominate on the human gastrointestinal mucosa are: L. plantarum, L. rhamnosus and L. paracasei ssp.…”

Diversity of the genus Lactobacillus revealed by comparative genomics of five species

“…It has been extensively studied for its probiotic properties in human trials and animal models (Dunne et al, 1999(Dunne et al, , 2001McCarthy et al, 2003;Sheil et al, 2004). Members of this species are commonly isolated from the oral and GI tracts of humans and other animals (Ahrne et al, 1998;Heilig et al, 2002;Molin et al, 1993;Rogosa et al, 1953). The 2?13 Mb genome of L. salivarius UCC118 comprised a 1?83 Mb chromosome, a 242 kb megaplasmid and two smaller plasmids of 20 kb and 44 kb.…”