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Lactiplantibacillus plantarum TWK10, a probiotic strain, has been demonstrated to improve exercise performance, regulate body composition, and ameliorate age-related declines. Here, we performed a comparative analysis of viable and heat-killed TWK10 in the regulation of exercise performance, body composition, and gut microbiota in humans. Healthy adults (n = 53) were randomly divided into three groups: Control, TWK10 (viable TWK10, 3 × 1011 colony forming units/day), and TWK10-hk (heat-killed TWK10, 3 × 1011 cells/day) groups. After six-week administration, both the TWK10 and TWK10-hk groups had significantly improved exercise performance and fatigue-associated features and reduced exercise-induced inflammation, compared with controls. Viable TWK10 significantly promoted improved body composition, by increasing muscle mass proportion and reducing fat mass. Gut microbiota analysis demonstrated significantly increasing trends in the relative abundances of Akkermansiaceae and Prevotellaceae in subjects receiving viable TWK10. Predictive metagenomic profiling revealed that heat-killed TWK10 administration significantly enhanced the signaling pathways involved in amino acid metabolisms, while glutathione metabolism, and ubiquinone and other terpenoid-quinone biosynthesis pathways were enriched by viable TWK10. In conclusion, viable and heat-killed TWK10 had similar effects in improving exercise performance and attenuating exercise-induced inflammatory responses as probiotics and postbiotics, respectively. Viable TWK10 was also highly effective in regulating body composition. The differences in efficacy between viable and heat-killed TWK10 may be due to differential impacts in shaping gut microbiota. [ABSTRACT FROM AUTHOR]

We developed a PCR-based method to detect and quantify viable Bifidobacterium bifidum BF-1 cells in human feces. This method (PMA-qPCR) uses propidium monoazide (PMA) to distinguish viable from dead cells and quantitative PCR using a BF-1-specific primer set designed from the results of randomly amplified polymorphic DNA analysis. During long-term culture (10 days), the number of viable BF-1 cells detected by counting the number of CFU on modified MRS agar, by measuring the ATP contents converted to CFU, and by using PMA-qPCR decreased from about 1010 to 106 cells/ml; in contrast, the total number of (viable and dead) BF-1 cells detected by counting 4',6-diamidino-2-phenylindolee (DAPI)-stained cells and by using qPCR without PMA and reverse transcrip- tion-qPCR remained constant. The number of viable BF-1 cells in fecal samples detected by using PMA-qPCR was highly and significantly correlated with the number of viable BF-1 cells added to the fecal samples, within the range of 105.3 to 10.3 cells/g feces (wet weight) (r> 0.99, P < 0.001). After 12 healthy subjects ingested 1010.3 to 1011.0 CFU of BF-1 in a fermented milk product daily for 28 days, 104.5 ± standard deviation [SD]) BF-1 CFU/g was detected in fecal samples by using strain-specific selective agar; in contrast, 106.2 ± 0.4 viable BF-1 cells/g were detected by using PMA-qPCR, and a total of 1076 ± 0.7 BF-1 cells/g were detected by using qPCR without PMA. Thus, the number of viable BF-1 cells detected by PMA-qPCR was about 50 times higher (P < 0.01) than that de- tected by the culture-dependent method. We conclude that strain-specffic PMA-qPCR can be used to quickly and accurately evaluate viable BF-1 in feces. [ABSTRACT FROM AUTHOR]

Asia differs substantially among and within its regions populated by diverse ethnic groups, which maintain their own respective cultures and dietary habits. To address the diversity in their gut microbiota, we characterized the bacterial community in fecal samples obtained from 303 school-age children living in urban or rural regions in five countries spanning temperate and tropical areas of Asia. The microbiota profiled for the 303 subjects were classified into two enterotype-like clusters, each driven by Prevotella (P-type) or Bifidobacterium/Bacteroides (BB-type), respectively. Majority in China, Japan and Taiwan harbored BB-type, whereas those from Indonesia and Khon Kaen in Thailand mainly harbored P-type. The P-type microbiota was characterized by a more conserved bacterial community sharing a greater number of type-specific phylotypes. Predictive metagenomics suggests higher and lower activity of carbohydrate digestion and bile acid biosynthesis, respectively, in P-type subjects, reflecting their high intake of diets rich in resistant starch. Random-forest analysis classified their fecal species community as mirroring location of resident country, suggesting eco-geographical factors shaping gut microbiota. In particular, children living in Japan harbored a less diversified microbiota with high abundance of Bifidobacterium and less number of potentially pathogenic bacteria, which may reflect their living environment and unique diet. [ABSTRACT FROM AUTHOR]

The composition of the human gut microbiota is related to host health, and it is thought that dietary habits may play a role in shaping this composition. Here, we examined the population size and prevalence of six predominant bacterial genera and the species compositions of genus Bifidobacterium (g-Bifid) and Bacteroides fragilis group (g-Bfra) in 42 healthy Belgian adults by quantitative PCR (qPCR) over a period of one month. The population sizes and prevalence of these bacteria were basically stable throughout the study period. The predominant g-Bifid species were Bifidobacterium adolescentis and Bifidobacterium longum ss. longum, and the predominant g-Bfra species were Bacteroides vulgatus, Bacteroides uniformis, and Bacteroides ovatus. The Belgian gut microbiota data were then compared with gut microbiota data from 46 Japanese subjects collected according to the same protocol (Matsuki et al., Appl. Environ. Microbiol. 70, 167–173, 2004). The population size and prevalence of Bifidobacterium catenulatum group were significantly lower in the Belgian gut microbiota than in the Japanese gut microbiota (P < 0.001); however, the population size and prevalence of g-Bifid did not differ. This species-level qPCR analysis will be helpful for investigating the diversity of gut microbiota among ethnic groups. [Copyright &y& Elsevier]