Lactobacillus gasseri BNR17 Ameliorates Dexamethasone-Induced Muscle Loss in BALB/c Mice and C2C12 Myotubes.

This study aimed to investigate the effects and mechanism of Lactobacillus gasseri BNR17, a probiotic strain isolated from human breast milk, on dexamethasone-induced muscle loss in mice and cultured myotubes. BALB/c mice were intraperitoneally injected with dexamethasone, and orally administered L. gasseri BNR17 for 21 days. L. gasseri BNR17 treatment ameliorated dexamethasone-induced decline in muscle function, as evidenced by an increase in forelimb grip strength, treadmill running time, and rotarod retention time in both female and male mice. In addition, L. gasseri BNR17 treatment significantly increased the mass of the gastrocnemius and quadriceps muscles. Dual-energy X-ray absorptiometry showed a significant increase in lean body mass and a decrease in fat mass in both whole body and hind limb after treatment with L. gasseri BNR17. It was found that L. gasseri BNR17 treatment downregulated serum myostatin level and the protein degradation pathway composed of muscle-specific ubiquitin E3 ligases, MuRF1 and MAFbx, and their transcription factor FoxO3. In contrast, L. gasseri BNR17 treatment upregulated serum insulin-like growth factor-1 level and Akt-mTOR-p70S6K signaling pathway involved in protein synthesis in muscle. As a result, L. gasseri BNR17 treatment significantly increased the levels of major muscular proteins such as myosin heavy chain and myoblast determination protein 1. Consistent with in vivo results, L. gasseri BNR17 culture supernatant significantly ameliorated dexamethasone-induced C2C12 myotube atrophy in vitro. In conclusion, L. gasseri BNR17 ameliorates muscle loss by downregulating the protein degradation pathway and upregulating the protein synthesis pathway.

Effects of multi-species probiotic supplementation on alcohol metabolism in rats.

Probiotics are known to protect against liver damage induced by the alcohol and acetaldehyde accumulation associated with alcohol intake. However, there have been few studies of the direct effect of probiotics on alcohol metabolism, and the types of probiotics that were previously analyzed were few in number. Here, we investigated the effects of 19 probiotic species on alcohol and acetaldehyde metabolism. Four probiotic species that had a relatively high tolerance to alcohol and metabolized alcohol and acetaldehyde effectively were identified: Lactobacillus gasseri CBT LGA1, Lactobacillus casei CBT LC5, Bifidobacterium lactis CBT BL3, and Bifidobacterium breve CBT BR3. These species also demonstrated high mRNA expression of alcohol and acetaldehyde dehydrogenases. ProAP4, a mixture of these four probiotics species and excipient, was then administered to rats for 2 weeks in advance of acute alcohol administration. The serum alcohol and acetaldehyde concentrations were significantly lower in the ProAP4-administered group than in the control and excipient groups. Thus, the administration of ProAP4, containing four probiotic species, quickly lowers blood alcohol and acetaldehyde concentrations in an alcohol and acetaldehyde dehydrogenasedependent manner. Furthermore, the serum alanine aminotransferase activity, which is indicative of liver damage, was significantly lower in the ProAP4 group than in the control group. The present findings suggest that ProAP4 may be an effective means of limiting alcohol-induced liver damage.

A synbiotic combination of Lactobacillus gasseri 505 and Cudrania tricuspidata leaf extract prevents hepatic toxicity induced by colorectal cancer in mice.

Colorectal cancer (CRC) is known to be a life-threatening disease and commonly leads to metastasis in the liver. Fermented milk acts as an effective carrier for probiotic strains, whose consumption improves host health. Our previous study indicated that fermented milk that included a synbiotic combination of Lactobacillus gasseri 505 (505) and Cudrania tricuspidata leaf extract (CT) resulted in significantly greater anti-oxidative effects than fermented milk without CT. Therefore, we hypothesized that fermented milk containing CT and 505 (FCT) could result in hepatoprotective effects against CRC-induced liver metastasis. Liver inflammation and CRC were induced in male C57BL/6J mice, using azoxymethane/dextran sodium sulfate, and 505, CT, and FCT were administered to the 3 sample-treated 505, CT, and FCT groups, respectively, for 10 wk. The results showed that FCT treatment significantly reduced serum aspartate aminotransferase and alanine aminotransferase concentrations and elevated albumin concentrations. Moreover, the results of histological analysis showed that hepatic steatosis was notably reduced in the FCT group. Among the 3 sample-treated groups, the expression of mRNA associated with enzymes showing anti-oxidative activities, such as superoxide dismutase, catalase, and glutathione reductase, was the highest in the FCT-treated mice. In addition, FCT administration resulted in the greatest anti-inflammatory activity, as inflammatory marker levels (i.e., tumor necrosis factor-α, cyclooxygenase-2, myeloperoxidase, and nuclear factor kappa-light-chain enhancer of activated B cells) were significantly downregulated at the mRNA level and the expression of proteins associated with the nuclear factor kappa-light-chain enhancer of activated B cells and mitogen-activated protein kinase signaling pathways was suppressed by FCT. Therefore, this study demonstrated that fermented milk containing novel synbiotics has the potential to prevent hepatic toxicity induced because of CRC owing to its enhanced anti-oxidative and anti-inflammatory activities.

Metabolomic profiling of oxalate-degrading probiotic Lactobacillus acidophilus and Lactobacillus gasseri.

Oxalate, a ubiquitous compound in many plant-based foods, is absorbed through the intestine and precipitates with calcium in the kidneys to form stones. Over 80% of diagnosed kidney stones are found to be calcium oxalate. People who form these stones often experience a high rate of recurrence and treatment options remain limited despite decades of dedicated research. Recently, the intestinal microbiome has become a new focus for novel therapies. Studies have shown that select species of Lactobacillus, the most commonly included genus in modern probiotic supplements, can degrade oxalate in vitro and even decrease urinary oxalate in animal models of Primary Hyperoxaluria. Although the purported health benefits of Lactobacillus probiotics vary significantly between species, there is supporting evidence for their potential use as probiotics for oxalate diseases. Defining the unique metabolic properties of Lactobacillus is essential to define how these bacteria interact with the host intestine and influence overall health. We addressed this need by characterizing and comparing the metabolome and lipidome of the oxalate-degrading Lactobacillus acidophilus and Lactobacillus gasseri using ultra-high-performance liquid chromatography-high resolution mass spectrometry. We report many species-specific differences in the metabolic profiles of these Lactobacillus species and discuss potential probiotic relevance and function resulting from their differential expression. Also described is our validation of the oxalate-degrading ability of Lactobacillus acidophilus and Lactobacillus gasseri, even in the presence of other preferred carbon sources, measuring in vitro 14C-oxalate consumption via liquid scintillation counting.

Lactobacillus gasseri in the Upper Small Intestine Impacts an ACSL3-Dependent Fatty Acid-Sensing Pathway Regulating Whole-Body Glucose Homeostasis.

Long-chain acyl-CoA synthetase (ACSL)-dependent upper small intestinal lipid metabolism activates pre-absorptive pathways to regulate metabolic homeostasis, but whether changes in the upper small intestinal microbiota alter specific fatty acid-dependent pathways to impact glucose homeostasis remains unknown. We here first find that upper small intestinal infusion of Intralipid, oleic acid, or linoleic acid pre-absorptively increases glucose tolerance and lowers glucose production in rodents. High-fat feeding impairs pre-absorptive fatty acid sensing and reduces upper small intestinal Lactobacillus gasseri levels and ACSL3 expression. Transplantation of healthy upper small intestinal microbiota to high-fat-fed rodents restores L. gasseri levels and fatty acid sensing via increased ACSL3 expression, while L. gasseri probiotic administration to non-transplanted high-fat-fed rodents is sufficient to restore upper small intestinal ACSL3 expression and fatty acid sensing. In summary, we unveil a glucoregulatory role of upper small intestinal L. gasseri that impacts an ACSL3-dependent glucoregulatory fatty acid-sensing pathway.

The growth kinetics and metabolic and antioxidant activities of the functional synbiotic combination of Lactobacillus gasseri 505 and Cudrania tricuspidata leaf extract.

In a previous study, the synbiotic combination of selected Lactobacillus gasseri strains and Cudrania tricuspidata leaf extract (CT) was shown to significantly improve the functionality of fermented milk, and the greatest synbiotic effect was exhibited with L. gasseri 505. The aim of the present study was to investigate the growth kinetics and fermentation metabolism of this specific synbiotic combination. Fermentation was carried out in synthetic media and milk with or without CT supplementation using L. gasseri 505. Whole genome sequencing and comparative genomics analyses were conducted to verify the novelty of strain. Titratable acidity, pH, microbial population, and organic acid production were measured during the fermentation period. The addition of CT accelerated the acidification rate, supporting the growth of L. gasseri 505, and the production of fermentation metabolites such as lactic acid and pyruvic acid also significantly increased during fermentation of both of CT-supplemented synthetic media and milk. In particular, the formic acid and propionic acid in CT were significantly utilized during fermentation of milk by L. gasseri 505. Moreover, the antioxidant capacity of CT-supplemented fermented milk increased due to the release of bioactive compounds until the exponential growth phase, after which the antioxidant activity declined due to degradation and loss of potency. Therefore, this study established that L. gasseri 505 efficiently utilized the CT-related nutrients during fermentation producing resulting metabolites with health-promoting effects, although it is necessary to control the fermentation time to obtain dairy products with optimum functionality.

Improved functionality of fermented milk is mediated by the synbiotic interaction between Cudrania tricuspidata leaf extract and Lactobacillus gasseri strains.

This study was designed to investigate the cooperative effect of selected Lactobacillus gasseri strains and Cudrania tricuspidata (CT) leaf extract in enhancing the health-promoting activities of fermented milk. Addition of CT increased total bacterial counts and proteolysis during fermentation of milk with L. gasseri strains. Antioxidant capacities were determined by measuring the ABTS, DPPH, and peroxyl radical scavenging activities and ferric reducing power. The antioxidant capacity of CT-supplemented milk was greater than that of milk without supplementation; moreover, the antioxidant activity of CT-supplemented milk was synergistically improved by fermentation with L. gasseri strains. In particular, CT-supplemented milk fermented by L. gasseri 505 showed the highest antioxidant activity. The phenolic compounds in CT, such as neo-chlorogenic, chlorogenic, and caffeic acid, were metabolized during fermentation with L. gasseri strains, and 3,4-dihydroxy-hydrocinnamic acid was produced as a fermentation metabolite. Moreover, the liberation of bioactive peptides of fermented milk was increased by the proteolytic activity of L. gasseri strains. In particular, six peptides, which were mainly derived from ß-casein, were newly identified in this study. These findings suggest that L. gasseri strains metabolize the phenolic acids in the CT and the bioactive peptides released through this interaction improve the antioxidant activity of the fermented milk.