Intestinal Lactobacilli of Estonian and Swedish Children

Abstract

The prevalence of intestinal lactobacilli was compared for sets of Estonian (71) and Swedish (65) 1–2-year-old children. A total of 227 Lactobacillus isolates from 50 Estonian and 30 Swedish children were collected. The distribution of the three lactobacilli fermentation types, obligate homofermenta tive, facultative heteroferment ative and obligate heteroferment ative (OHOL, FHEL and OHEL) was assessed among 138 Estonian and 89 Swedish paediatric isolates of lactobacilli according to their gas production from glucose and also their growth at different temperatures. Furthermore, 76 selected OHOL, FHEL and OHEL isolates from 18 (36%) Estonian and 13 (43%) Swedish children were typed using gas chromatographic analysis. In addition, species-level identi? cation was performed using an API 50 CHL kit (bioMe´rieux, Lyon, France) and internal-transcribed spacer PCR coupled with restriction analysis. The Swedish children examined were less frequently colonized with Lactobacillus sp. than the Estonian children (46% vs. 70% children; p< 0.01). The prevalence of the OHOL, OHEL and FHEL groups was found to be similar within both sets of children with FHEL present in 72% of Estonian and 80% of Swedish children. Utilizing both pheno- and genotypin g systems seven species were found within the Estonian group of children versus three species within the Swedish group. The API 50CHL identified a further three Lactobacillus species in the Estonian group and one additional species in the Swedish group. Significantly, Lactobacillus plantarum strains were present in 33% of Estonian children tested but were not present in Swedish children ( p< 0.05). Thus, among young children regional differences may occur in the number and species of intestinal lactobacilli. These differences between infants in the two countries with a low and a high prevalence of allergy are of interest in the suggested role of lactobacilli as immune modulators. Keywords: children, lactobacilli, obligate homofermentative, facultative heteroferment ative, obligate heteroferment ative species, prevalence.