Role of polyamines in intestinal mucosal barrier function.

The intestinal epithelium is a rapidly self-renewing tissue; the rapid turnover prevents the invasion of pathogens and harmful components from the intestinal lumen, preventing inflammation and infectious diseases. Intestinal epithelial barrier function depends on the epithelial cell proliferation and junctions, as well as the state of the immune system in the lamina propria. Polyamines, particularly putrescine, spermidine, and spermine, are essential for many cell functions and play a crucial role in mammalian cellular homeostasis, such as that of cell growth, proliferation, differentiation, and maintenance, through multiple biological processes, including translation, transcription, and autophagy.

Sugar and arginine facilitate oral tolerance by ensuring the functionality of tolerogenic immune cell subsets in the intestine.

Although oral tolerance is a critical system in regulating allergic disorders, the mechanisms by which dietary factors regulate the induction and maintenance of oral tolerance remain unclear. To address this, we explored the differentiation and function of various immune cells in the intestinal immune system under fasting and ad libitum-fed conditions before oral ovalbumin (OVA) administration. Fasting mitigated OVA-specific Treg expansion, which is essential for oral tolerance induction.

Distinct lactate metabolism between hepatocytes and myotubes revealed by live cell imaging with genetically encoded indicators.

The process of glycolysis breaks down glycogen stored in muscles, producing lactate through pyruvate to generate energy. Excess lactate is then released into the bloodstream. When lactate reaches the liver, it is converted to glucose, which muscles utilize as a substrate to generate ATP.

Mitochondrial ATP concentration decreases immediately after glucose administration to glucose-deprived hepatocytes.

Hepatocytes can switch their metabolic processes in response to nutrient availability. However, the dynamics of metabolites (such as lactate, pyruvate, and ATP) in hepatocytes during the metabolic switch remain unknown. In this study, we visualized metabolite dynamics in primary cultured hepatocytes during recovery from glucose-deprivation.

Strain-level detection of in colorectal cancer specimens by targeting the CRISPR-Cas region.

is one of the predominant oral bacteria in humans. However, this bacterium is enriched in colorectal cancer (CRC) tissues and may be involved in CRC development. Our previous research suggested that is present in CRC tissues originating from the oral cavity using a traditional strain-typing method [arbitrarily primed polymerase chain reaction (AP-PCR)].

subsp. and arginine mixture intake improves cognitive flexibility in mice.

The relationship between intestinal microbiota and cognitive function has been investigated as one of the major topics within the intestinal microbiota-gut-brain axis. Although an increasing number of studies have demonstrated an improvement in learning and memory when using probiotics or prebiotics, to date, there are no studies that target the cognitive flexibility observed in the early stages of several neuropsychiatric diseases, including dementia. We have recently developed a novel behavioral task using the touchscreen operant system to assess cognitive flexibility.

Effects of Intestinal Bacterial Hydrogen Gas Production on Muscle Recovery following Intense Exercise in Adult Men: A Pilot Study.

This study aimed to examine the effects of hydrogen gas (H) produced by intestinal microbiota on participant conditioning to prevent intense exercise-induced damage. In this double-blind, randomized, crossover study, participants ingested H-producing milk that induced intestinal bacterial H production or a placebo on the trial day, 4 h before performing an intense exercise at 75% maximal oxygen uptake for 60 min. Blood marker levels and respiratory variables were measured before, during, and after exercise.

Impact of Intestinal Microbiota on Cognitive Flexibility by a Novel Touch Screen Operant System Task in Mice.

Cognitive flexibility is the ability to rapidly adapt to a constantly changing environment. It is impaired by aging as well as in various neurological diseases, including dementia and mild cognitive impairment. In rodents, although many behavioral test protocols have been reported to assess learning and memory dysfunction, few protocols address cognitive flexibility.

Putrescine Production by KP 3-4 Isolated from Fermented Foods.

Polyamines are aliphatic hydrocarbons with terminal amino groups and are essential for biological activities. It has been reported that polyamines have health-promoting effects in animals, such as the extension of lifespan by polyamine intake. The identification of a high polyamine-producing bacterium from foods could lead to the development of a novel probiotic candidate.

A prospective interventional trial on the effect of periodontal treatment on Fusobacterium nucleatum abundance in patients with colorectal tumours.

Fusobacterium nucleatum is associated with the progression of colorectal cancer. Thus, the possibility of preventing colorectal cancer or its progression by targeting F. nucleatum has been explored.

Symbiotic polyamine metabolism regulates epithelial proliferation and macrophage differentiation in the colon.

Intestinal microbiota-derived metabolites have biological importance for the host. Polyamines, such as putrescine and spermidine, are produced by the intestinal microbiota and regulate multiple biological processes. Increased colonic luminal polyamines promote longevity in mice.

Green fluorescent protein-based lactate and pyruvate indicators suitable for biochemical assays and live cell imaging.

Glycolysis is the metabolic pathway that converts glucose into pyruvate, whereas fermentation can then produce lactate from pyruvate. Here, we developed single fluorescent protein (FP)-based lactate and pyruvate indicators with low EC for trace detection of metabolic molecules and live cell imaging and named them "Green Lindoblum" and "Green Pegassos," respectively. Green Lindoblum (EC of 30 µM for lactate) and Green Pegassos (EC of 70 µM for pyruvate) produced a 5.

Polyamines polarized Th2/Th9 cell-fate decision by regulating GATA3 expression.

Polyamines produced by both prokaryotes and eukaryotes are bioactive substances with pleiotropic effects. Accumulating evidence has demonstrated that polyamines contribute to anti-inflammatory responses by suppressing the expression of proinflammatory cytokines in mononuclear cells and macrophages. However, the effects of polyamines on CD4 T cell responses remain to be elucidated.

Microbiota-derived butyrate limits the autoimmune response by promoting the differentiation of follicular regulatory T cells.

Background: Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disorder with a high prevalence, especially in industrialized countries. Dysbiosis of the intestinal microbiota has been observed in RA patients. For instance, new-onset untreated RA (NORA) is associated with the underrepresentation of the Clostridium cluster XIVa, including Lachnospiraceae, which are major butyrate producers, although the pathological relevance has remained obscure.

The benefit of elobixibat in chronic constipation is associated with faecal deoxycholic acid but not effects of altered microbiota.

Background: Elobixibat, a novel inhibitor of apical sodium-dependent bile acid transporter for treating chronic constipation, increases colonic bile acid concentrations, stimulating bowel function. However, it is not clear which bile acids are altered, or whether altered gut microbiota are associated with functional effects that may alter bowel function.

Aims: To investigate the effects of elobixibat on changes in the faecal concentrations of total and individual bile acids and in faecal microbiota.

Prevention of Atherosclerosis by the Induction of Microbial Polyamine Production in the Intestinal Lumen.

Low molecular weight metabolites produced by the intestinal microbiome that have been associated with health and disease as metabolites need to be constantly absorbed from the intestinal lumen and transported to intestinal epithelial cells and blood. Polyamines, especially spermidine and spermine, are bioactive chemicals which promote autophagy and suppress inflammation. The main source of exogenous polyamines is the intestinal lumen, where they are produced by intestinal microbiome.

Hydrogen-producing milk to prevent reduction in tear stability in persons using visual display terminals.

Purpose: To examine the effect of hydrogen (H)-producing milk, which induces H production by intestinal microbiota, on the prevention of dry eye disease.

Methods: A randomized, double-blind, placebo-controlled, parallel-group comparative study was conducted in humans. Of 118 candidates aged 20-60 years who were using visual display terminals daily, 54 subjects (mean age, 42.

Endothelial Function is improved by Inducing Microbial Polyamine Production in the Gut: A Randomized Placebo-Controlled Trial.

Recently, it was demonstrated that spermidine-induced autophagy reduces the risk of cardiovascular disease in mice. Intestinal bacteria are a major source of polyamines, including spermidine. We previously reported that the intake of both subsp.

Free D-amino acids produced by commensal bacteria in the colonic lumen.

D-amino acids (D-AAs) have various biological activities, such as activation of N-methyl-D-aspartic acid (NMDA) receptor as a co-agonist by D-Ser. Since several free D-AAs are released in the broth monocultured with bacterium and D-AAs are probably utilized for bacterial communication, we presume that intestinal microbiota releases several kinds of free D-AAs, which may be involved in the hosts' health. However, presently, only four free D-AAs have been found in the ceacal lumen, but not in the colonic lumen.

Taxonomic classification for microbiome analysis, which correlates well with the metabolite milieu of the gut.

Background: 16S rRNA gene amplicon sequencing analysis (16S amplicon sequencing) has provided considerable information regarding the ecology of the intestinal microbiome. Recently, metabolomics has been used for investigating the crosstalk between the intestinal microbiome and the host via metabolites. In the present study, we determined the accuracy with which 16S rRNA gene data at different classification levels correspond to the metabolome data for an in-depth understanding of the intestinal environment.

Intestinal luminal putrescine is produced by collective biosynthetic pathways of the commensal microbiome.

The intestinal microbiome produces various metabolites that may harm or benefit the host. However, the production pathways of these metabolites have not been well characterised. The polyamines putrescine and spermidine required for physiological process are also produced by intestinal microbiome.

Bioactive polyamine production by a novel hybrid system comprising multiple indigenous gut bacterial strategies.

Metabolites of the intestinal microbiota are thought to be generated through metabolic pathways spanning multiple taxa of intestinal bacteria. We have previously shown that the level of putrescine, a polyamine found abundantly in the human intestinal lumen, is increased in the colonic lumen following administration of arginine and the probiotic sp.; however, the underlying mechanism remained poorly understood.

Colonic Absorption of Low-Molecular-Weight Metabolites Influenced by the Intestinal Microbiome: A Pilot Study.

Low-molecular-weight metabolites produced by the intestinal microbiome play a direct role in health and disease. However, little is known about the ability of the colon to absorb these metabolites. It is also unclear whether these metabolites are bioavailable.

A Novel Putrescine Exporter SapBCDF of Escherichia coli.

Recent research has suggested that polyamines (putrescine, spermidine, and spermine) in the intestinal tract impact the health of animals either negatively or positively. The concentration of polyamines in the intestinal tract results from the balance of uptake and export of the intestinal bacteria. However, the mechanism of polyamine export from bacterial cells to the intestinal lumen is still unclear.