• Journal of Microbiology and Biotechnology
• /
• v.33 no.12
• /
• pp.1657-1670
• /
• 2023

This study aimed to evaluate the effects of Limosilactobacillus fermentum and Lactiplantibacillus plantarum isolated from human feces coordinating with inulin on the composition of gut microbiota and metabolic profiles in db/db mice. These supplements were administered to db/db mice for 12 weeks. The results showed that the Lactobacillaceae coordinating with inulin group (LI) exhibited lower fasting blood glucose levels than the model control group (MC). Additionally, LI was found to enhance colon tissue and increase the levels of short-chain fatty acids. 16S rRNA sequencing revealed that the abundance of Corynebacterium and Proteus, which were significantly increased in the MC group compared with NC group, were significantly decreased by the treatment of LI that also restored the key genera of the Lachnospiraceae_NK4A136_group, Lachnoclostridium, Ruminococcus_gnavus_group, Desulfovibrio, and Lachnospiraceae_UCG-006. Untargeted metabolomics analysis showed that lotaustralin, 5-hydroxyindoleacetic acid, and 13(S)-HpODE were increased while L-phenylalanine and L-tryptophan were decreased in the MC group compared with the NC group. However, the intervention of LI reversed the levels of these metabolites in the intestine. Correlation analysis revealed that Lachnoclostridium and Ruminococcus_gnavus_group were negatively correlated with 5-hydroxyindoleacetic acid and 13(S)-HpODE, but positively correlated with L-tryptophan. 13(S)-HpODE was involved in the "linoleic acid metabolism". L-tryptophan and 5-hydroxyindoleacetic acid were involved in "tryptophan metabolism" and "serotonergic synapse". These findings suggest that LI may alleviate type 2 diabetes symptoms by modulating the abundance of Ruminococcus_gnavus_group and Lachnoclostridium to regulate the pathways of "linoleic acid metabolism", "serotonergic synapse", and" tryptophan metabolism". Our results provide new insights into prevention and treatment of type 2 diabetes.

• Journal of Species Research
• /
• v.10 no.2
• /
• pp.117-133
• /
• 2021

In 2019, 43 bacterial strains were isolated from food, soil, marine environments, human, and animals related sources from the Republic of Korea. Based on the analysis of 16S rRNA gene sequence, these isolates were allocated to the phyla Bacteroidetes and Firmicutes as unrecorded species in Korea. The 10 Bacteroidetes strains were classified into the families Bacteroidaceae, Chitinophagaceae, Cytophagaceae, Flavobacteriaceae, and Prolixibacteraceae (of the orders Bacteroidales, Chitinophagales, Cytophagales, Flavobacteriales, and Marinilabiliales, respectively). The 33 Firmicutes strains belonged to the families Bacillaceae, Paenibacillaceae, Planococcaceae, Staphylococcaceae, Clostridiaceae, Lachnospiraceae, Peptostreptococcaceae, Enterococcaceae, Lactobacillaceae, Leuconostocaceae, and Streptococcaceae (of the orders Bacillales, Clostridiales, and Lactobacillales). These unrecorded bacteria were determined based on taxonomic criterion (>98.7%; 16S rRNA gene sequence similarity). In addition, their phylogenetic affiliation, as well as cell and colony morphologies, staining reactions, and physiological and biochemical properties were investigated. Therefore, we report 43 isolates as unrecorded species, and described basic features, isolation source, and locations of these strains.