Distinctive Intestinal Lactobacillus Communities in 6-Month-Old Infants From Rural Malawi and Southwestern Finland

Objective:Our aim was to compare the composition and diversity of Lactobacillus microbiota in infants living in Malawi and Southwestern Finland.Methods:The composition and diversity of the Lactobacillus group was analyzed in the feces of healthy 6-month-old infants living in rural Malawi (n=44) and Southwestern Finland (n=31), using the quantitative polymerase chain reaction method and PCR-denaturing gradient gel electrophoresis fingerprinting.Results:Malawian infants had higher counts of lactobacilli than their Finnish counterparts (7.45 log cells/g vs 6.86 log cells/g, P<0.001, respectively) and the Lactobacillus community was richer and more diverse in the Malawian infants. Leuconostoc citreum and Weissella confusa were the predominant species in both study groups, but Malawian infants were more often colonized by these species (100% vs 74.2%, P<0.001; 95.5% vs 41.9%, P<0.001, respectively). Moreover, Lactobacillus ruminis, Lactobacillus gasseri, Lactobacillus acidophilus, and Lactobacillus mucosae were detected more often in the Malawian infants (59.1% vs 0.0%, P<0.001; 38.6% vs 9.7%, P=0.004; 29.5% vs 0.0%, P<0.001; 22.7% vs 3.2%, P=0.017, respectively). Lactobacillus casei group species, however, were only detected in the Finnish infants.Conclusions:Malawian infants have a more abundant Lactobacillus microbiota with a distinct composition compared with Finnish infants. The environment, including diet and hygiene, may be among the factors influencing these differences.