Lactococcus cremoris subsp. cremoris FC-fermented milk activates protein synthesis and increases skeletal muscle mass in middle-aged mice.

Age-related muscle atrophy is associated with decreased protein anabolic capacity. Dietary intervention is an important strategy for the treatment of age-related muscle atrophy. This study examined the effect of Lactococcus cremoris subsp. cremoris FC-fermented milk on muscle mass and protein anabolic signaling in middle-aged mice. Male C57BL/6J mice (18-month-old) were divided into the control and Lactococcus cremoris subsp. cremoris FC-fermented milk supplementation groups. Mice were administered unfermented or fermented milk (300 µL/day) by gavage every alternate day for 8 weeks; thereafter, muscle weight, protein metabolic signaling factors, and inflammatory factors were investigated. Soleus muscle weight was higher in the fermented milk group than in the control group. Expression of insulin growth factor-1, a typical anabolic factor, and phosphorylation levels of anabolic signaling factors (mTOR and p70S6K) were higher after fermented milk supplementation. Levels of tumor necrosis factor-α, an inhibitor of protein anabolism, were lower in the fermented milk group. These data suggest that the daily intake of Lactococcus cremoris subsp. cremoris FC-fermented milk increased skeletal muscle mass as well as protein synthesis in the middle-aged mice, which may be mediated by reduction in the levels of inflammatory factors. Therefore, accelerated protein synthesis, induced by the consumption of fermented milk, has a potential role in counteracting muscle atrophy.

The effects of fermented milk containing Lactococcus lactis subsp. cremoris FC on defaecation in healthy young Japanese women: a double-blind, placebo-controlled study.

The objective of this double-blind, placebo-controlled study was to elucidate the effects of fermented milk containing Lactococcus lactis subsp. cremoris FC (FC) on defaecation in healthy young women. We included 31 women (18-31 years old) who were randomly selected into two groups. Subjects in the test group consumed fermented milk containing FC, while subjects in the placebo group consumed non-fermented gelled milk. In the test group, defaecation frequency (both in days and times per week) and stool volume significantly increased during the consumption of fermented milk containing FC compared with before consumption. These effects were also observed in subjects with mild constipation. Furthermore, in subjects with mild constipation, stool ammonia concentration was significantly lower in the test group than that in the placebo group after 4 weeks. These results suggest that fermented milk containing FC is beneficial for improving defaecation and faecal properties.

Prolonged Lifespan, Improved Perception, and Enhanced Host Defense of Caenorhabditis elegans by Lactococcus cremoris subsp. cremoris.

Lactic acid bacteria are beneficial to Caenorhabditis elegans; however, bacteria acting as probiotics in nematodes may not necessarily have probiotic functions in humans. Lactococcus cremoris subsp. cremoris reportedly has probiotic functions in humans. Therefore, we determined whether the strain FC could exert probiotic effects in C. elegans in terms of improving host defenses and extending life span. Live FC successfully extended the life span and enhanced host defense compared to Escherichia coli OP50 (OP50), a standard food source for C. elegans. The FC-fed worms were tolerant to Salmonella enterica subsp. enterica serovar Enteritidis or Staphylococcus aureus infection and had better survival than the OP50-fed control worms. Further, the chemotaxis index, an indicator of perception ability, was more stable and significantly higher in FC-fed worms than in the control worms. The increase in autofluorescence from advanced glycation end products (AGEs) with aging was also ameliorated in FC-fed worms. FC showed beneficial effects in daf-16 and pmk-1 mutants, but not in skn-1 mutants. Since SKN-1 is the C. elegans ortholog of Nrf2, we measured the transcription of heme oxygenase-1 (HO-1), which is regulated by Nrf2, in murine macrophages and found that HO-1 mRNA expression was increased >5 times by inoculation with FC cells. Thus, FC could exert antisenescence effects via the SKN-1/Nrf2 pathway. This study showed for the first time that FC supported perceptive function and suppressed AGEs in nematodes as probiotic bacteria. Therefore, C. elegans can be an alternative model to screen for probiotic bacteria that can be used for antisenescence effects in humans. IMPORTANCE Aging is one of our greatest challenges. The World Health Organization proposed that "active aging" might encourage people to continue to work according to their capacities and preferences as they grow old and would prevent or delay disabilities and chronic diseases that are costly to both individuals and the society, considering that disease prevention is more economical than treatment. Probiotic bacteria, such as lactobacilli, are live microorganisms that exert beneficial effects on human health when ingested in sufficient amounts and can promote longevity. The significance of this study is that it revealed the antisenescence and various beneficial effects of the representative probiotic bacterium Lactococcus cremoris subsp. cremoris strain FC exerted via the SKN-1/Nrf2 pathway in the nematode Caenorhabditis elegans.

Comparative Genome Analysis of Three Komagataeibacter Strains Used for Practical Production of Nata-de-Coco.

We determined the whole genome sequences of three bacterial strains, designated as FNDCR1, FNDCF1, and FNDCR2, isolated from a practical nata-de-coco producing bacterial culture. Only FNDCR1 and FNDCR2 strains had the ability to produce cellulose. The 16S rDNA sequence and phylogenetic analysis revealed that all strains belonged to the Komagataeibacter genus but belonged to a different clade within the genus. Comparative genomic analysis revealed cross-strain distribution of duplicated sequences in Komagataeibacter genomes. It is particularly interesting that FNDCR1 has many duplicated sequences within the genome independently of the phylogenetic clade, suggesting that these duplications might have been obtained specifically for this strain. Analysis of the cellulose biosynthesis operon of the three determined strain genomes indicated that several cellulose synthesis-related genes, which are present in FNDCR1 and FNDCR2, were lost in the FNDCF1 strain. These findings reveal important genetic insights into practical nata de coco-producing bacteria that can be used in food development. Furthermore, our results also shed light on the variation in their cellulose-producing abilities and illustrate why genetic traits are unstable for Komagataeibacter and Komagataeibacter-related acetic acid bacteria.