栃尾 巧

Psychiatric disorders such as major depressive disorder are closely linked to the intestinal environment, suggesting intestinal health may contribute to their prevention. Prebiotics, which enhance intestinal health, are promising candidates for preventing psychiatric disorders. 1-Kestose (kestose), a type of prebiotics, has shown potential, but its effects on psychiatric disorders remain unclear. In this study, we investigated whether kestose prevents abnormal behaviors induced by social isolation (SI) stress and which underlies mechanisms of preventive effects. C57BL/6J male mice (3 weeks old) were divided into two groups: individually housed (SI) group and housed five mice per cage (GH) group. Each group received either a normal diet or a kestose diet (5% kestose) for 5 weeks daily until the end of the behavioral testing. Kestose prevented the SI-induced abnormal behaviors including reduced sociality, impaired spatial recognition, and heightened anxiety, which were associated with suppressed microglial activation in the hippocampus. Kestose altered the diversity of gut microbiota and increased the abundance of Bacteroides sartorii. Furthermore, short-chain fatty acids (SCFAs) such as butyric acid, acetic acid, and propionic acid, produced by intestinal microbiota, were increased after kestose supplementation. Positive correlations were observed between B. sartorii abundance and SCFA levels, suggesting that B. sartorii contributes to SCFA production. Notably, both B. sartorii and SCFAs were strongly associated with the abnormal behaviors by SI. These findings suggest that kestose prevents SI-induced abnormal behaviors by modulating gut microbiota, particularly B. sartorii, through an increase of SCFA production. Taken together, kestose could be used as a promising prebiotic intervention for psychiatric disorders.

Background/Objectives: Nopalea cochenillifera (L.) Salm-Dyck cladodes are rich in dietary fiber, polyphenols, and minerals, which are known to exert antioxidant and immunomodulatory effects. However, the mechanisms and active constituents have not been fully elucidated. In this study, we investigated the effects of continuous N. cochenillifera consumption on lipid metabolism, immune function, and the gut microbiota in mice. Methods: The feed was made using freeze-dried and powdered cladodes of N. cochenillifera. Male C57BL/6J mice were assigned to four groups: control diet (C), control diet plus 10% N. cochenillifera (CN), high-fat diet (FC), and high-fat diet plus 10% N. cochenillifera (FN). Results: Cactus supplementation reduced the body and liver weights that were elevated by the high-fat diet. Serum total cholesterol and free fatty acids were increased in the FC group compared with the C group, while cactus intake lowered these levels and enhanced fecal cholesterol excretion. Cactus consumption also elevated fecal total IgA and mucin contents. IL-4 expression in Peyer's patches was significantly increased in the FN group compared with the FC group. Gut microbiota analysis showed significant differences in β-diversity, along with increased α-diversity and higher abundance of Lachnospiraceae, following cactus intake. Conclusions: These findings suggest that N. cochenillifera intake increases gut microbiota diversity, which enhances intestinal barrier function and thereby contributes to improved lipid metabolism and immune regulation.

BACKGROUND: Erythritol, a sugar alcohol, has been reported to suppress the in vitro growth of Staphylococcus pseudintermedius and Staphylococcus coagulans. OBJECTIVES: To determine whether erythritol suppresses the growth of Staphylococcus hyicus, a major pathogen causing porcine exudative epidermitis, and to investigate the molecular mechanisms involved in erythritol-induced S. hyicus growth suppression. MATERIALS AND METHODS: An in vitro turbidity assay was performed to assess the effect of erythritol on the growth of 26 S. hyicus strains, including a reference strain JCM 2423 and the 25 wild strains isolated from pigs. Differentially expressed genes in response to erythritol in JCM 2423 were identified by RNA-Seq and quantitative reverse transcription-PCR. The impact of trehalose, glucose and arginine supplementation on erythritol-induced growth suppression of the 25 S. hyicus wild strains was also investigated. RESULTS: Erythritol suppressed the in vitro growth of JCM 2423 and the 25 S. hyicus wild strains. Moreover, erythritol upregulated the transcription of multiple genes in JCM 2423, including those encoding ATP-binding cassette transporter enzymes (potB, potC and potD), arginine biosynthetic pathway enzymes (argF, argG and argH), l-arginine deiminase pathway enzymes (arcA, arcC and arcD), fatty acid metabolism pathway enzymes (fabH and fabF) and trehalose metabolism-related proteins (treC, treR and treP). Supplementation of trehalose or glucose in aerobic conditions or arginine supplementation in anaerobic conditions restored in vitro growth of the 25 S. hyicus wild strains treated by erythritol. CONCLUSIONS AND CLINICAL RELEVANCE: Erythritol suppresses the in vitro growth of S. hyicus by inhibiting intracellular sugar and arginine metabolism under aerobic and anaerobic conditions, respectively.

BACKGROUND: Ventilator-associated pneumonia (VAP) after tracheal intubation is a major infectious complication in patients in the intensive care unit (ICU), with an incidence of 8-28%. Oral care in the ICU is essential; however, the presence of an intubation tube and restricted mouth opening cause complications. A healthy commensal microflora in the oral cavity resists colonization by respiratory pathogens, and poor oral hygiene may increase the risk for VAP. In this study, we examined the effectiveness of oral care on oral bacterial counts and microbial diversity in patients admitted to the ICU. METHODS: Fifteen ICU patients were included in this study. Oral microbiome samples were collected by swabbing the surface of the tongue. Oral bacterial counts were measured at four time points: before and after oral care, both pre- and post-extubation. Additionally, microbiome analysis was conducted twice: once before oral care pre-extubation, and once before oral care post-extubation. Oral bacterial counts were assessed using a bacterial counter, and microbiome analysis was performed through 16S rRNA gene amplicon sequencing. RESULTS: Oral bacterial counts significantly decreased after oral care at both pre- and post-extubation time points. Microbiome analysis revealed significant differences in alpha diversity pre- and post-extubation samples. Samples post extubation were less diverse. CONCLUSIONS: This study demonstrates that oral care effectively reduces bacterial counts in ICU patients, both pre- and post-extubation. Microbiome analysis revealed shifts in microbial diversity, suggesting that the oral microbiota was disrupted during intubation. Given the risk of VAP, oral care may play an important role to prevent VAP in ICU settings.

INTRODUCTION: Gastrectomy considerably affects the gut microbiome; however, the association between dysbiosis and post-gastrectomy syndrome remains to be explored. This study prospectively explored fecal gut microbiota alterations before and 3 months after gastrectomy, investigating their potential association with weight loss. METHODS: The gut microbiome of 21 patients with gastric cancer scheduled for gastrectomy in April-October 2022 was analyzed using 16S rRNA gene Next-Generation Sequencing. Their microbiome profiles were compared to those of healthy controls. Bacterial taxa demonstrating significant changes were determined using the Linear Discriminant Analysis Effect Size algorithm and further analyzed for their relationship with weight loss in the gastrectomy cohort. RESULTS: Postoperative complications (≥grade 2) were observed in 14.3% of patients. Postoperative weight loss was －10.9%, with the following breakdown: distal (－7.0%), total (－13.5%), and proximal (－14.0%) gastrectomy (P = 0.003). Microbiota analysis demonstrated a significant incline in the abundance of the Streptococcus salivarius group and a decline in Bacteroides uniformis in patients with gastric cancer compared to healthy controls. The S. salivarius group exhibited a further increase, while B. uniformis showed signs of recovery after gastrectomy. Additionally, 5α-reductase gene levels, reported to decrease as several cancers progress, were found to elevate post-surgery. Furthermore, patients experiencing greater weight loss showed a significant reduction in Faecalibacterium prausnitzii levels, while lower serum prealbumin and zinc levels were associated with the abundance of Escherichia coli. CONCLUSION: Gastrectomy significantly alters the gut microbiome. Supporting microbiome health with prebiotics may help alleviate postoperative issues and improve patients' quality of life.

Feline atopic skin syndrome (FASS) is a chronic inflammatory skin disease characterized by itching and dermatitis. While the relationship between the gut microbiota and atopic dermatitis (AD) has been highlighted, exploring gut-targeted therapies for FASS remain limited. This study aimed to evaluate the effects of a parasynbiotic containing 1-kestose and heat-killed Lactobacillus plantarum FM8 on clinical symptoms and gut microbiota in cats with FASS. Eleven FASS cats were treated with a parasynbiotic containing 1-kestose (400 mg/day) and heat-killed FM8 (2.0 × 1010 CFU/day) for 8 weeks. Clinical symptoms were assessed using the SCORing Feline Allergic Dermatitis (SCORFAD), investigator pruritus score (IPS), and rating of global assessment of improvement (GAI). Fecal microbiota composition was analyzed through 16S rRNA sequencing, with 16 healthy cats serving as controls. Parasynbiotic intervention significantly reduced SCORFAD and IPS scores. GAI scores improved in 10 of 11 cats, with the most severe case maintaining a score of 3. The β-diversity analysis showed no significant differences; however, a trend toward variation was observed between the healthy control cats and the baseline group of FASS cats, as well as between the healthy control cats and post- intervention groups. The abundance of Collinsella stercoris was significantly higher in FASS cats than in healthy controls, and it significantly decreased after parasynbiotic intervention, suggesting potential improvements in gut health and inflammation. This study is the first to demonstrate the potential benefits of parasynbiotic administration in FASS, showing improvements in clinical symptoms and partial modulation of the gut microbiota. These findings highlight parasynbiotic administration as a compelling therapeutic approach for FASS, offering new possibilities for innovative interventions aimed at the gut–skin axis.

The gut microbiota has been implicated in the modulation of food allergies. Building on previous studies on the preventive effects of combining short-chain fructan 1-kestose (Kes) and long-chain fructan inulin (Inu) in food allergies, we investigated their therapeutic effects in an ovalbumin (OVA)-induced food allergy mouse model. Following OVA sensitization, the mice received 5% Kes and Inu, either individually or a combined 2.5% dose of each, for 4 wk. We assessed allergy-related markers, such as OVA-specific serum IgE (OVA-sIgE) levels, in the blood and monitored changes in the gut microbiome. The intake of fructans ameliorated allergic symptoms and stabilized rectal temperatures, with a significant reduction in OVA-sIgE levels only in the combined Kes and Inu group (Kes+Inu), p<0.05. Gut microbiota diversity analysis revealed significant differences in beta diversity between the groups not receiving fructans and those receiving Kes, Inu, or Kes+Inu (p<0.01 each). Specifically, in the Kes+Inu group, the abundance of the genus UBA7173 belonging to the family Muribaculaceae significantly increased. Additionally, acetate levels were significantly elevated only in the Kes+Inu group and correlated positively with the presence of the genus UBA7173. These findings indicated that the combined intake of Kes and Inu improves allergic outcomes, positively affects the gut microbiome, and enhances the production of acetate.

OBJECTIVES: Colorectal cancer (CRC) is a major global health concern, and surgical resection remains its primary treatment. However, the impact of different surgical procedures on gut microbiota and their influence on postoperative outcomes remain unclear. This study investigated changes in the gut microbiota following three types of CRC resections: right-sided colectomy (RSC), left-sided colectomy (LSC), and low anterior resection (LAR). METHODS: Fecal samples were collected from 34 patients with CRC who underwent curative resection at Fujita Health University Hospital between April 2022 and December 2023. Bacterial profiling was performed using 16S rRNA gene amplicon sequencing. The results were compared with data from 85 healthy controls. RESULTS: Significant alterations in gut microbiota composition were observed in surgical groups compared to the healthy control (Ctrl) group. The RSC group exhibited the greatest reduction in alpha diversity, likely because of ileocecal valve loss. Beta-diversity analysis revealed distinct microbial profiles between the Ctrl group and the surgical groups, with notable alterations in key bacterial species. The RSC group exhibited significant reduction in beneficial bacteria, including Faecalibacterium prausnitzii and Bifidobacterium spp., alongside increase in Escherichia coli, suggesting a shift toward a pro-inflammatory environment. In contrast, the LSC and LAR groups exhibited enrichment of Akkermansia muciniphila, which may promote gut barrier integrity and immune modulation. CONCLUSIONS: CRC resection induces site-specific changes in gut microbiota composition. These microbial alterations may affect postoperative inflammation, metabolism, and cancer recurrence risk. Further studies are necessary to explore microbiome-targeted strategies for improving postoperative outcomes in cases of CRC.

Negative experiences during adolescence, such as social isolation (SI), bullying, and abuse, increase the risk of psychiatric diseases in adulthood. However, the pathogenesis of psychiatric diseases induced by these factors remain poorly understood. In adolescents, stress affects the intestinal homeostasis in the gut-brain axis. This study determined whether adolescent SI induces behavioral abnormalities by disrupting colonic function. Adolescent mice exposed to SI exhibit spatial cognitive deficits and microglial activation in the hippocampus (HIP). SI decreased the differentiation of mucin-producing goblet cells, which was accompanied by alterations in the composition of the gut microbiota, particularly the depletion of mucin-feeding bacteria. Treatment with rebamipide, which promotes goblet cell differentiation in the colon, attenuated SI-induced spatial cognitive deficits and microglial activation in the HIP and decreased cystine, a downstream metabolite of homocysteine. Treatment with cystine ameliorated SI-induced spatial cognitive deficits and increased microglial C-C motif chemokine ligand 7 (CCL7) levels in the HIP. Inhibition of CCL7 receptors by antagonists of CC motif chemokine receptors 2 (CCR2) and 3 (CCR3) in the HIP prevented spatial cognitive deficits induced by SI. Infusion of CCL7 into the HIP following microglial ablation with clodronate liposome induced spatial cognitive deficits. These findings suggest that adolescent SI decreases serum cystine levels by damaging the colonic goblet cells, resulting in spatial cognitive deficits by triggering microglial activation in the HIP. Our results indicate that increased CCL7 expression in hippocampal microglia may contribute to spatial cognitive deficits by activating CCR2 and CCR3.

As the global population continues to grow, so too does the demand for poultry meat. However, the concurrent increase in the prevalence of drug-resistant bacteria has stimulated interest in the search for alternatives to antibiotics in poultry and livestock agriculture. One potential strategy is the use of probiotics. In this study, we showed that prophylactic oral administration of Limosilactobacillus ingluviei C37 (LIC37) reduced Campylobacter jejuni colonization of the cecum in cage-raised chicks, without causing significant changes in the overall diversity of gut bacteria. Further, the abundance of Blautia, another genus of probiotic bacteria, increased in the gastrointestinal tract following ingestion of LIC37 by chicks. These findings suggest that LIC37 could potentially be used as a novel probiotic agent against C. jejuni in livestock production.

Recent studies have linked Ruminococcus gnavus to inflammatory bowel disease and Fusobacterium nucleatum to various cancers. Agarooligosaccharides (AOS), derived from the acid hydrolysis of agar, have shown significant inhibitory effects on the growth of R. gnavus and F. nucleatum at concentrations of 0.1 and 0.2%, respectively. RNA sequencing and quantitative reverse-transcription PCR analyses revealed the downregulation of fatty acid biosynthesis genes (fab genes) in these bacteria when exposed to 0.1% AOS. Furthermore, AOS treatment altered the fatty acid composition of R. gnavus cell membranes, increasing medium-chain saturated fatty acids (C8, C10) and C18 fatty acids while reducing long-chain fatty acids (C14, C16). In contrast, no significant growth inhibition was observed in several strains of Bifidobacteria and Lactobacillales at AOS concentrations of 0.2 and 2%, respectively. Co-culture experiments with R. gnavus and Bifidobacterium longum in 0.2% AOS resulted in B. longum dominating the population, constituting over 96% post-incubation. In vivo studies using mice demonstrated a significant reduction in the Lachnospiraceae family, to which R. gnavus belongs, following AOS administration. Quantitative PCR also showed lower levels of the nan gene, potentially associated with immune disorders, in the AOS group. These findings suggest that AOS may introduce a novel concept in prebiotics by selectively inhibiting potentially pathogenic bacteria while preserving beneficial bacteria such as Bifidobacteria and Lactobacillales.

Aim: This study aimed to establish a non-invasive, rapid, and cost-effective method to assess the potential risk of immune and psychiatric disorders by quantifying nan gene levels in gut microbiota, specifically focusing on Ruminococcus gnavus and other Lachnospiraceae species associated with mucin degradation. Methodology: We first designed a primer set targeting the consensus sequence of the nanA gene, which is highly conserved within nan gene clusters. To validate this primer set, we performed Next-Generation Sequencing (NGS) on the PCR-amplified fragments. To explore the association between nan levels and immune or psychiatric disorders, we conducted qPCR to quantify nan levels in the intestines, analyzing intestinal DNA from both allergy-induced mice with or without fructan treatment, and dogs with or without aggressive behavior. Additionally, to assess whether nan levels reflect the clinical status of immune disorders, fecal samples were collected from 45 patients with ulcerative colitis (UC) and analyzed for nan levels. Results: NGS analysis of DNA fragments amplified from various intestinal samples using the nan primer set confirmed the presence of nanA sequences from R. gnavus and other members of the Lachnospiraceae family, including Blautia and Dorea species. The qPCR quantification of nan levels using this primer set revealed that allergy-induced mice treated with fructans, which are known to be associated with lower allergy scores compared to untreated mice, exhibited significantly reduced nan levels. Additionally, the nan levels of aggressive dogs were substantially higher than those of non-aggressive dogs. Notably, nan levels were also substantially elevated in patients with UC in comparison to the healthy control individuals. Conclusion: qPCR-based measurement of nan levels in gut microbiota shows potential for selectively detecting pathogenic nan-harboring strains and may reflect the clinical status of immune and psychiatric disorders. This approach could provide a non-invasive, rapid, and cost-effective method for assessing the risk of these disorders.

BACKGROUND/PURPOSE: Gut microbiota status after pancreaticoduodenectomy (PD) is unclear, and postoperative fatty liver is an important complication after PD. This study evaluated the relationship between postoperative fatty liver and gut microbiota after PD. METHODS: Fecal samples were collected from patients who had undergone PD and remained stable after 6 months of follow-up. A comprehensive bacterial analysis using 16S rRNA gene amplicon sequencing was performed. The results were compared with those of 85 healthy volunteers. The association between perioperative factors, gut microbiota, and development of fatty liver was investigated. RESULTS: Twenty-four patients after PD, including 10 in the fatty liver (FL) group and 14 in the normal liver (NL) group were investigated. The β-diversity of the gut microbiota was significantly different between the healthy volunteers and patients after PD, with more Escherichia coli and Streptococcus gallolyticus and less Bifidobacterium catenulatum and Faecalibacterium prausnitzii in the patients with PD. Lactobacillus gasseri was significantly less abundant in the FL group than in the healthy volunteers, although this change was not observed in the NL group. CONCLUSIONS: The gut microbiota of patients after PD was in dysbiosis at postoperative ≥6 months. Development of fatty liver might be associated with significant differences in gut microbiota.

Introduction. Hepatocellular carcinoma (HCC) is one of the deadliest cancers worldwide.Gap statement. Monitoring of HCC and predicting its immunotherapy responses are challenging.Aim. This study explored the potential of the gut microbiome for HCC monitoring and predicting HCC immunotherapy responses.Methods. DNA samples were collected from the faeces of 22 patients with HCC treated with atezolizumab/bevacizumab (Atz/Bev) and 85 healthy controls. The gut microbiome was analysed using 16S rRNA next-generation sequencing and quantitative PCR (qPCR).Results. The microbiomes of patients with HCC demonstrated significant enrichment of Lactobacillus, particularly Lactobacillus fermentum, and Streptococcus, notably Streptococcus anginosus. Comparative analysis between Atz/Bev responders (R) and non-responders (NR) revealed a higher abundance of Bacteroides stercoris in the NR group and Bacteroides coprocola in the R group. Using qPCR analysis, we observed elevated levels of S. anginosus and reduced levels of 5α-reductase genes, essential for the synthesis of isoallolithocholic acid, in HCC patients compared to controls. Additionally, the analysis confirmed a significantly lower abundance of B. stercoris in the Atz/Bev R group relative to the NR group.Conclusions. The gut microbiome analysis and specific gene quantification via qPCR could provide a rapid, less invasive, and cost-effective approach for assessing the increased risk of HCC, monitoring patient status, and predicting immunotherapy responses.

Less than half of all patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) respond to chemotherapy, and the prognosis of PDAC is poor, which may be mediated by the gut microbiota. We investigated the clinical improvement effects of 1-kestose, a fructooligosaccharide, on PDAC chemotherapy in this single-center, randomized, controlled pilot trial conducted at Fujita Health University Hospital, which enrolled patients with PDAC. The trial included 1-kestose administration and non-administration groups. The 1-kestose group received 9 g of 1-kestose daily for 12 weeks, and their blood markers, imaging studies, physical findings, and gut microbiota were evaluated. In the 1-kestose administration group, the cancer marker CA19-9 significantly decreased, and there was a reduction in the neutrophil-to-lymphocyte ratio (NLR). There was also suppression of the reduction of albumin levels and of an increase in C-reactive protein. Additionally, Escherichia coli, which typically increases in PDAC, significantly decreased in the 1-kestose group. Thus, 1-kestose altered the gut microbiota and improved the prognostic factors for PDAC. Large-scale, long-term trials of 1-kestose interventions for PDAC are thus warranted to improve the prognosis of PDAC.

(1) Background: Proglucagon-derived peptides (PDGPs) including glucagon (Gcg), GLP-1, and GLP-2 regulate lipid metabolism in the liver, adipocytes, and intestine. However, the mechanism by which PGDPs participate in alterations in lipid metabolism induced by high-fat diet (HFD) feeding has not been elucidated. (2) Methods: Mice deficient in PGDP (GCGKO) and control mice were fed HFD for 7 days and analyzed, and differences in lipid metabolism in the liver, adipose tissue, and duodenum were investigated. (3) Results: GCGKO mice under HFD showed lower expression levels of the genes involved in free fatty acid (FFA) oxidation such as Hsl, Atgl, Cpt1a, Acox1 (p &lt; 0.05), and Pparα (p = 0.05) mRNA in the liver than in control mice, and both FFA and triglycerides content in liver and adipose tissue weight were lower in the GCGKO mice. On the other hand, phosphorylation of hormone-sensitive lipase (HSL) in white adipose tissue did not differ between the two groups. GCGKO mice under HFD exhibited lower expression levels of Pparα and Cd36 mRNA in the duodenum as well as increased fecal cholesterol contents compared to HFD-controls. (4) Conclusions: GCGKO mice fed HFD exhibit a lesser increase in hepatic FFA and triglyceride contents and adipose tissue weight, despite reduced β-oxidation in the liver, than in control mice. Thus, the absence of PGDP prevents dietary-induced fatty liver development due to decreased lipid uptake in the intestinal tract.

Introduction. Colorectal cancer (CRC) is a leading cause of cancer deaths, closely linked to the intestinal microbiota and bile acid metabolism. Secondary bile acids, like deoxycholic and lithocholic acid, are associated with increased CRC risk due to their disruption of vital cellular functions. In contrast, isoallolithocholic acid (isoalloLCA) shows potential health benefits, highlighting the complex role of bile acids in CRC. A specific primer set was previously developed to amplify homologs of the 5α-reductase gene (5ar), which are involved in the biosynthesis of isoalloLCA, thereby enabling the estimation of abundance of 5ar (5ar levels) in the intestine.Hypothesis/Gap Statement. We hypothesized that 5ar levels in the intestine are associated with CRC.Aim. This study aimed to investigate intestinal 5ar levels and compare them across different stages of the adenoma-carcinoma sequence, providing insights into novel strategies for monitoring CRC risk.Methodology. DNA was extracted from intestinal lavage fluids (ILF) collected during 144 colonoscopies. Next-generation sequencing (NGS) was employed to examine the sequence of 5ar homologues, using a specific primer set on DNA from seven selected ILFs - four from carcinoma patients and three from individuals with non-neoplastic mucosa. Additionally, we used quantitative PCR (qPCR) to measure 5ar levels in all 144 DNA samples.Results. We conducted 144 colonoscopies and categorized patients according to the adenoma-cancer sequence: 52 with non-neoplastic mucosa, 69 with adenomas and 23 with carcinoma. Analysis of 292,042 NGS-derived 5ar sequences revealed the seven most prevalent amplicon sequence variants, each 254 base pairs in length. These closely matched or were identical to 5ar sequences in Bacteroides uniformis, Phocaeicola vulgatus and Phocaeicola dorei. Furthermore, qPCR analysis demonstrated significantly lower 5ar levels in the carcinoma group compared to those in the non-neoplastic mucosa group (P = 0.0004). A similar, though not statistically significant, trend was observed in the adenoma group (P = 0.0763), suggesting that 5ar levels decrease as CRC progresses.Conclusion. These findings indicate that PCR-based monitoring of 5ar levels in intestinal samples over time could provide a non-invasive, rapid and cost-effective method for assessing an increased risk of CRC.

Staphylococcus coagulans (SC) belongs to a group of coagulase-positive staphylococci occasionally isolated from the skin lesions of dogs with pyoderma. We recently revealed that erythritol, a sugar alcohol, inhibited the growth of SC strain JCM7470. This study investigated the molecular mechanisms involved in this growth inhibition of JCM7470 by erythritol, and determine whether erythritol inhibits the growth of SC isolated from the skin of dogs with pyoderma. Comprehensive analysis of the gene expression of JCM7470 in the presence of erythritol revealed that erythritol upregulated the expression of glcB and ptsG genes, both of which encode phosphotransferase system (PTS) glucoside- and glucose-specific permease C, B, and A domains (EIICBA), respectively, associated with sugar uptake. Moreover, erythritol suppressed in vitro growth of all 27 SC strains isolated from the skin lesions of canine pyoderma, including 13 mecA gene-positive and 14 mecA gene-negative strains. Finally, the growth inhibition of the SC clinical isolates by erythritol was restored by the addition of glucose. In summary, we revealed that erythritol promotes PTS gene expression and suppresses the in vitro growth of SC clinical isolates from dogs with pyoderma. Restoration of the erythritol-induced growth inhibition by glucose suggested that glucose starvation may contribute to the growth inhibition of SC.

Probiotics such as bifidobacteria have been given to low-birth-weight neonates (LBWNs) at risk for a disrupted gut microbiota leading to the development of serious diseases such necrotizing enterocolitis. Recently prebiotics such as lactulose are used together with bifidobacteria as synbiotics. However, faster and more powerful bifidobacteria growth is desired for better LBWN outcomes. The prebiotic 1-kestose has a higher selective growth-promoting effect on bifidobacteria and lactic acid bacteria in vitro among several oligosaccharides. Twenty-six premature neonates (less than 2,000 g) admitted to a neonatal intensive care unit (NICU) were randomly assigned to receive Bifidobacterium breve M16-V with either 1-kestose or lactulose once a day for four weeks from birth. A 16S rRNA gene analysis revealed similar increases in alpha-diversity from 7 to 28 days in both groups. The most dominant genus on both days was Bifidobacterium in both groups, with no significant difference between the two groups. Quantitative PCR analysis revealed that the number of Staphylococcus aureus tended to be lower in the 1-kestose group than in the lactulose group at 28 days. The number of Escherichia coli was higher in the 1-kestose group at 7 days. The copy number of total bacteria in the 1-kestose group was significantly higher than that in the lactulose group at 3 time points, 7, 14, and 28 days. No severe adverse events occurred in either group during the study period. l-Ketose may offer an alternative option to lactulose as a prebiotic to promote the development of gut microbiota in LBWNs.

In recent years, an increased emphasis on enhancing the care and health management of captive marine mammals has been observed. Belugas (White Whale, Delphinapterus leucas), belonging to the family Monodontidae, are of considerable importance and often the centerpiece of aquarium collections worldwide. This study aimed to investigate the effects of the administration of prebiotics on the gut microbiota and overall health of the beluga. Prebiotic 1-kestose, a fructooligosaccharide comprising sucrose and fructose, was administered to three belugas, alongside their regular vitamin supplements for a duration of 8 weeks. 16S rRNA gene amplicon sequencing of intestinal DNA revealed that the relative abundance of the genus Turicibacter, a potentially pathogenic bacteria, significantly reduced after 1-kestose administration when compared to that at baseline (P=0.050). In addition, a quantitative PCR analysis revealed that the levels of collagenase gene, a putative virulence factor gene of Turicibacter, significantly reduced after 1-kestose administration (P=0.050). Blood creatinine levels that were initially above the normal value also reduced after 1-kestose administration (P=0.023). Therefore, this study demonstrated the potential of 1-kestose to improve the health and welfare of aquarium belugas.

Silkworm (Bombyx mori) larvae are expected to be useful as an ingredient in entomophagy. They are full of nutrients, including indigestible proteins; however, there have been few studies on the effects of the consumption of the entire body of silkworms on the intestinal microflora. We prepared a customized diet containing silkworm larval powder (SLP), and investigated the effects of ad libitum feeding of the SLP diet on the intestinal microbiota and the amount of short-chain fatty acids (SCFAs) in mice. We found that the diversity of the cecal and fecal microbiota increased in the mice fed the SLP diet (SLP group), and that the composition of their intestinal microbiota differed from that of the control mice. Furthermore, a genus-level microbiota analysis showed that in the SLP group, the proportions of Alistipes, Lachnospiraceae A2, and RF39, which are associated with the prevention of obesity, were significantly increased, while the proportions of Helicobacter and Anaerotruncus, which are associated with obesity, were significantly decreased. Additionally, the level of butyrate was increased in the SLP group, and Clostridia UCG 014 and Lachnospiraceae FCS020 were found to be associated with the level of butyrate, one of the major SCFAs. These findings indicated that silkworm powder may be useful as an insect food that might also improve obesity.

Despite the well-known potential health benefits of prebiotics and non-viable probiotics (paraprobiotics) in various animal species, research regarding their use in penguins is scarce. Our study aimed to investigate the impact of a combined administration of prebiotics and paraprobiotics (referred to here as "parasynbiotics") on the gut microbiome and overall health of Magellanic penguins (Spheniscus magellanicus). The parasynbiotics consisted of 1-kestose, which is a fructooligosaccharide comprising sucrose and fructose, and heat-killed Lactiplantibacillus plantarum FM8, isolated from pickled vegetables. It was administered to eight penguins aged <3 years (Young-group) and nine penguins aged >17 years (Adult-group) for 8 weeks. Results from 16S rRNA sequencing revealed that compared to baseline, parasynbiotic administration significantly decreased the relative abundance of intestinal Clostridiaceae_222000 in both groups and significantly increased that of Lactobacillaceae in the Young-group. Quantitative real-time polymerase chain reaction revealed a significant decrease in the plc gene levels encoding alpha-toxin of Clostridium perfringens in the Young-group after parasynbiotic administration (P=0.0078). In the Young-group, parasynbiotic administration significantly increased the plasma levels of total alpha-globulin (P=0.0234), which is associated with inflammatory responses. Furthermore, exposure of dendritic cells to heat-killed L. plantarum FM8 promoted the secretion of interleukin 10, a major anti-inflammatory cytokine. Overall, parasynbiotic administration enhanced the activity of gut Lactobacillaceae, decreased the levels of C. perfringens and its toxin encoding plc gene, and reduced inflammatory response in penguins. These results provide novel insights into the potential benefits of parasynbiotics for improving penguin health.

Abstract Background and Aim Potassium‐competitive acid blockers more strongly suppress the gastric acid barrier than proton pump inhibitors and cause dysbiosis. However, preventive measures in this regard have not been established. We aimed to evaluate whether 1‐kestose, a known prebiotic, was effective at alleviating dysbiosis caused by potassium‐competitive acid blockers. Methods Patients scheduled to undergo endoscopic resection for superficial gastroduodenal tumors were enrolled and randomized 1:1 to receive either 1‐kestose or placebo. All patients were started on potassium‐competitive acid blocker (vonoprazan 20 mg/day) and took 1‐kestose 10 g/day or placebo (maltose) 5 g/day for 8 weeks. The primary outcome was the effect of 1‐kestose on potassium‐competitive acid blocker‐induced alterations in the microbiome. The fecal microbiome was analyzed before and after potassium‐competitive acid blocker treatment via MiSeq (16S rRNA gene V3–V4 region). Results Forty patients were enrolled, and 16 in each group were analyzed. In the placebo group, the Simpson index, an alpha diversity, was significantly decreased and relative abundance of Streptococcus was significantly increased by 1.9‐fold. In the kestose group, the Simpson index did not change significantly and relative abundance of Streptococcus increased 1.3‐fold, but this was not a significant change. In both groups, no adverse events occurred, ulcers were well healed, and pretreatment and posttreatment short‐chain fatty acid levels did not differ. Conclusions The potassium‐competitive acid blocker caused dysbiosis in the placebo group; this effect was prevented by 1‐kestose. Thus, 1‐kestose may be useful in dysbiosis treatment.

BACKGROUND: It has become clear that the intestinal microbiota plays a role in food allergies. The objective of this study was to assess the food allergy-preventive effects of combined intake of a short fructan (1-kestose [Kes]) and a long fructan (inulin ([Inu]) in an ovalbumin (OVA)-induced food allergy mouse model. RESULTS: Oral administration of fructans lowered the allergenic symptom score and alleviated the decreases in rectal temperature and total IgA levels and increases in OVA-specific IgE and IgA levels induced by high-dose OVA challenge, and in particular, combined intake of Kes and Inu significantly suppressed the changes in all these parameters. The expression of the pro-inflammatory cytokine IL-4, which was increased in the allergy model group, was significantly suppressed by fructan administration, and the expression of the anti-inflammatory cytokine IL-10 was significantly increased upon Kes administration. 16 S rRNA amplicon sequencing of the gut microbiota and beta diversity analysis revealed that fructan administration may induce gut microbiota resistance to food allergy sensitization, rather than returning the gut microbiota to a non-sensitized state. The relative abundances of the genera Parabacteroides B 862,066 and Alloprevotella, which were significantly reduced by food allergy sensitization, were restored by fructan administration. In Parabacteroides, the relative abundances of Parabacteroides distasonis, Parabacteroides goldsteinii, and their fructan-degrading glycoside hydrolase family 32 gene copy numbers were increased upon Kes or Inu administration. The concentrations of short-chain fatty acids (acetate and propionate) and lactate were increased by fructan administration, especially significantly in the Kes + Inu, Kes, and Inu-fed (Inu, Kes + Inu) groups. CONCLUSION: Combined intake of Kes and Inu suppressed allergy scores more effectively than single intake, suggesting that Kes and Inu have different allergy-preventive mechanisms. This indicates that the combined intake of these short and long fructans may have an allergy-preventive benefit.

PURPOSE: Postoperative diarrhea (PD) remains one of the significant complications. Only a few studies focused on PD after minimally invasive surgery. We aimed to investigate PD after minimally invasive gastrectomy for gastric cancer. METHODS: A total of 1476 consecutive patients with gastric cancer undergoing laparoscopic or robotic gastrectomy between 2009 and 2019 at our institution were retrospectively reviewed. PD was defined as continuous diarrhea for ≥ 2 days, positive stool culture, or positive clostridial antigen test. The incidence, causes, and related clinical factors were analyzed. RESULTS: Of the 1476 patients, the median age was 69 years. Laparoscopic and robotic approaches were performed in 1072 (72.6%) and 404 (27.4%), respectively. Postoperative complications with Clavien-Dindo classification grade of ≥ IIIa occurred in 108 (7.4%) patients. PD occurred in 89 (6.0%) patients. Of the 89 patients with PD, Clostridium difficile, enteropathogenic Escherichia coli, and methicillin-resistant Staphylococcus aureus were detected in 24 (27.0%), 16 (33.3%), and 7 (14.6%) patients, respectively. Multivariate analysis revealed that age ≥ 75 years (OR 1.62, 95% CI [1.02-2.60], p = 0.042) and postoperative complications (OR 6.04, 95% CI [3.54-10.32], p < 0.001) were independent risk factors for PD. In patients without complications, TG (OR 1.88) and age of ≥ 75 years(OR 1.71) were determined as independent risk factors. CONCLUSION: The incidence of PD following minimally invasive gastrectomy for gastric cancer was 6.0%. Older age and TG were obvious risk factors in such a surgery, with the latter being a significant risk even in the absence of complications.

BACKGROUND: Erythritol was found to inhibit the growth of microorganisms. The present study aimed to demonstrate the growth inhibition of Staphylococcus pseudintermedius by erythritol and to define the changes in gene transcription signatures induced by erythritol. Changes in the gene transcription profiles were analysed by RNA sequencing and quantitative reverse transcription PCR. Gene ontology analysis was performed to assign functional descriptions to the genes. RESULTS: Erythritol inhibited S. pseudintermedius growth in a dose-dependent manner. We then performed a transcriptome analysis of S. pseudintermedius with and without 5% (w/w) erythritol exposure to validate the mechanism of growth inhibition. We revealed that erythritol induced up-regulation of three genes (ptsG, ppdK, and ppdkR) that are related to the phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS). Glucose supplementation restored the up-regulation of the PTS-related genes in response to erythritol. In addition, erythritol down-regulated eleven genes that are located in a single pur-operon and inhibited biofilm formation of S. pseudintermedius. CONCLUSIONS: These findings indicated that erythritol antagonistically inhibits PTS-mediated glucose uptake, thereby exerting a growth inhibitory effect on S. pseudintermedius. Moreover, erythritol inhibits the 'de novo' IMP biosynthetic pathway that may contribute to biofilm synthesis in S. pseudintermedius.

A single-arm study was conducted with 10 children aged 2-12 years with severe cow's milk allergy (CMA) requiring complete allergen elimination. Subjects were administered kestose, a prebiotic, at 1 or 2 g/day for 12 weeks. Results of a subsequent oral food challenge (OFC) showed a statistically significant increase in the total dose of cow's milk ingestion (1.6 ml vs. 2.7 ml, p = 0.041). However, the overall evaluation of the OFC results, TS/Pro (total score of Anaphylaxis Scoring Aichi (ASCA)/cumulative dose of protein), showed no statistically significant improvement, although the values were nominally improved in seven out of 10 subjects. The 16S rDNA analysis of fecal samples collected from the subjects revealed a statistically significant increase in the proportion of Faecalibacterium spp. (3.8 % vs. 6.8%, p = 0.013), a type of intestinal bacterium that has been reported to be associated with food allergy. However, no statistically significant correlation was found between Faecalibacterium spp. abundance and the results of the OFC.

ABSTRACT The trisaccharide 1-kestose, a major constituent of fructooligosaccharide, has strong prebiotic effects. We used high-performance liquid chromatography and 1H nuclear magnetic resonance spectroscopy to show that BiBftA, a β-fructosyltransferase belonging to glycoside hydrolase family 68, from Beijerinckia indica subsp. indica catalyzes transfructosylation of sucrose to produce mostly 1-kestose and levan polysaccharides. We substituted His395 and Phe473 in BiBftA with Arg and Tyr, respectively, and analyzed the reactions of the mutant enzymes with 180 g/L sucrose. The ratio of the molar concentrations of glucose and 1-kestose in the reaction mixture with wild-type BiBftA was 100:8.1, whereas that in the reaction mixture with the variant H395R/F473Y was 100:45.5, indicating that H395R/F473Y predominantly accumulated 1-kestose from sucrose. The X-ray crystal structure of H395R/F473Y suggests that its catalytic pocket is unfavorable for binding of sucrose while favorable for transfructosylation.

By comparing germ-free mice and specific pathogen-free mice, we recently demonstrated that the presence of gut commensals upregulates microRNA-200 family members in lamina propria leukocytes (LPL) of the murine large intestine. The present study tested whether the consumption of 1-kestose (KES), an indigestible oligosaccharide that alters gut microbiota composition, influences the microRNA expression in the LPL. Supplementation of KES (4%) in drinking water for 2 wk increased the levels of miR-182-5p, -205-5p, -290a-5p, miR-200 family members (miR-141-3p, -200a-3p, -200b-3p, -200c-3p, and -429-3p) as well as miR-192/215 family members (miR-192-5p, -194-5p, and -215-5p) as determined by microarray analysis in large intestinal LPL of C57BL/6 mice. Quantitative reverse transcription-PCR further confirmed the increase in miR-192-5p, -194-5p, -200a-3p, -200b-3p, -200c-3p, -205-5p, and 215-5p. KES consumption significantly increased Bifidobacterium pseudolongum in the cecal contents. In a separate experiment, intragastric administration of B. pseudolongum (109 CFU/d) for 7 d increased the levels of miR-182-5p, -194-5p, and -200a-3p and tended to increase the levels of miR-200b-3p, -215-5p, and -429-3p. These results suggest that dietary KES influences miRNA expression in the large intestinal LPL, which may be associated with the increased population of B. pseudolongum.

Aggression in the animal kingdom is a necessary component of life; however, certain forms of aggression, especially in humans, are pathological behaviors that are detrimental to society. Animal models have been used to study a number of factors, including brain morphology, neuropeptides, alcohol consumption, and early life circumstances, to unravel the mechanisms underlying aggression. These animal models have shown validity as experimental models. Moreover, recent studies using mouse, dog, hamster, and drosophila models have indicated that aggression may be affected by the "microbiota-gut-brain axis." Disturbing the gut microbiota of pregnant animals increases aggression in their offspring. In addition, behavioral analyses using germ-free mice have shown that manipulating the intestinal microbiota during early development suppresses aggression. These studies suggest that treating the host gut microbiota during early development is critical. However, few clinical studies have investigated gut-microbiota-targeted treatments with aggression as a primary endpoint. This review aims to clarify the effects of gut microbiota on aggression and discusses the therapeutic potential of regulating human aggression by intervening in gut microbiota.

BACKGROUND: Interventions targeting the gut microbiota for treating food allergy (FA) have been gaining much attention. Although several studies have examined the effects of probiotics, few have verified the effects of prebiotic intervention on FA in humans. METHODS: We conducted a preliminary open-label, parallel-group comparison trial in children diagnosed with severe cow's milk allergy (CMA) who were instructed to ingest baked milk (BM; bread or cookies) daily. The subjects either received or did not receive the prebiotic 1-kestose (kestose) daily for 6 months. CMA symptoms and the threshold dose for milk protein were evaluated by oral food challenge with heated milk or BM. Blood and fecal samples were also collected for investigations of the antigen-specific immunoglobulin (Ig) E levels and microbiota composition. RESULTS: Kestose treatment significantly increased the threshold dose for milk protein, and decreased the milk- and casein-specific IgE levels in serum. In those treated with kestose, the abundance of Fusicatenibacter spp. significantly increased in the feces, and a significant inverse correlation was seen between the abundance of Fusicatenibacter spp. and the milk- and casein-specific IgE levels. CONCLUSION: Kestose treatment induced some tolerance to milk protein via changes in the gut microbiota composition in children with FA. IMPACT: A 6-month treatment with the prebiotic kestose increased the threshold dose for milk protein, and decreased the serum levels of milk- and casein-specific IgE in children diagnosed with cow's milk allergy. The kestose treatment increased the abundance of Fusicatenibacter spp. in the gut, which was inversely correlated with the antigen-specific IgE levels. This is the first study to demonstrate that a prebiotic intervention induced some tolerance to an allergen in children with food allergy.

Probiotics and prebiotics are viable bacteria with beneficial effects on the host and components that selectively act on the beneficial commensal bacteria, respectively. The combined use of probiotics and prebiotics is termed synbiotics. Probiotic intake improves dysbiosis in the intestinal microbiota and can positively affect canine atopic dermatitis (CAD). However, clinical studies on improvements in CAD using synbiotics remain limited. In this study, 15 dogs with CAD who received prednisolone, a synthetic glucocorticoid (GC) used in the treatment of CAD, for more than 90 days were continuously treated with Lactobacillus paracasei M-1 from fermented food as a probiotic, and trisaccharide kestose as a prebiotic, for 90 days to determine their synbiotic effects on CAD. The CAD symptoms were evaluated using the canine atopic dermatitis lesion index (CADLI) and pruritus visual analog scores (PVAS) at 30, 60 and 90 days after synbiotic administration. The total prednisolone use for 90 days pre- and post-administration was also evaluated. Synbiotic administration significantly reduced the CADLI (pre: median, 28.0 [22.0-32.0]; 30 days: median, 20.0 [20.0-28.0]; 60 days: median, 20.0 [10.0-21.0]; 90 days: median, 12.0 [10.0-19.0]) and PVAS (pre: median, 6.0 [5.0-7.0]; 30 days: median, 3.0 [3.0-3.5]; 60 days: median, 3.0 [3.0-3.5]; 90 days: median, 2.0 [2.0-3.5]) scores, and reduced the total prednisone use over 90 days (pre: 112.0 [25-450] mg; post: 80.0 [18.-300.0] mg; p⟨0.001) in the 15 dogs. Thus, the synbiotic activity of L. paracasei M-1 and trisaccharide kestose can improve CAD.

BACKGROUND: Ulcerative colitis involves an excessive immune response to intestinal bacteria. Whether administering prebiotic 1-kestose is effective for active ulcerative colitis remains controversial. AIMS: This randomised, double-blind, placebo-controlled pilot trial investigated the efficacy of 1-kestose against active ulcerative colitis. METHODS: Forty patients with mild to moderate active ulcerative colitis were randomly treated with 1-kestose (N = 20) or placebo (maltose, N = 20) orally for 8 weeks in addition to the standard treatment. The Lichtiger clinical activity index and Ulcerative Colitis Endoscopic Index of Severity were determined. Faecal samples were analysed to evaluate the gut microbiome and metabolites. RESULTS: The clinical activity index at week 8 was significantly lower in the 1-kestose group than in the placebo group (3.8 ± 2.7 vs. 5.6 ± 2.1, p = 0.026). Clinical remission and response rates were higher in the 1-kestose group than in the placebo group (remission: 55% vs. 20%, p = 0.048; response: 60% vs. 25%, p = 0.054). The Ulcerative Colitis Endoscopic Index of Severity at week 8 was not significantly different (2.8 ± 1.6 vs. 3.5 ± 1.6, p = 0.145). Faecal analysis showed significantly reduced alpha-diversity in the 1-kestose group, with a decreased relative abundance of several bacteria, including Ruminococcus gnavus group. The short-chain fatty acid levels were not significantly different between the groups. The incidence of adverse events was comparable between the groups. DISCUSSION: Oral 1-kestose is well tolerated and provides clinical improvement for patients with mild to moderate ulcerative colitis through modulation of the gut microbiome.

Pancreatic ductal adenocarcinoma (PDAC) can be treated with surgery, chemotherapy, and radiotherapy. Despite medical progress in each field in recent years, it is still insufficient for managing PDAC, and at present, the only curative treatment is surgery. A typical pancreatic cancer is relatively easy to diagnose with imaging. However, it is often not recommended for surgical treatment at the time of diagnosis due to metastatic spread beyond the pancreas. Even if it is operable, it often recurs during postoperative follow-up. In the case of PDAC with a diameter of 10 mm or less, the 5-year survival rate is as good as 80% or more, and the best index for curative treatment is tumor size. The early detection of pancreatic cancer with a diameter of less than 10 mm or carcinoma in situ is critical. Here, we provide an overview of the current status of diagnostic imaging features and genetic tests for the accurate diagnosis of early-stage PDAC.

Abstract Brevibacterium linens (B. linens) is a dairy microorganism used in the production of washed cheese. However, there has been little research on B. linens, especially regarding its effects in vivo. Herein, we report the morphological characteristics of B. linens, such as its two‐phase growth and V‐ and Y‐shaped bodies. We also report that oral administration of B. linens increased the diversity of the gut microbiota and promoted the growth of lactobacilli and short‐chain fatty acid‐producing bacteria, such as Lachnospiraceae and Muribaculaceae. These findings suggest that the ingestion of B. linens may have beneficial effects in humans and animals.