Psacalium decompositum is a shrub indigenous to northern Mexico and Arizona and New Mexico in the USA. It has been utilized in traditional medicine for the treatment of many ailments, including rheumatic disorders, pain, and diabetes. A chemical analysis of a hexane extract from the rhizomes of P. decompositum revealed the presence of sesquiterpenes, including cacalol, cacalone, maturin, and maturinone, among others. Furthermore, its aqueous fraction was subjected to isolation, resulting in the identification of linear fructooligosaccharides with an eight-unit polymerisation degree (LFOS8). The objective of this study was to ascertain the impact of LFOS8 derived from P. decompositum on the intestinal microbiota of rats through 16S rRNA gene sequencing and bioinformatics analysis. Male Wistar rats were randomly assigned to the following groups (n=8): a control group administered an isotonic saline solution, positive control group treated with chicory inulin (a prebiotic), and experimental group treated with LFOS8 fraction. The positive control and experimental groups of animals demonstrated alterations in their gut microbiota, resulting in an increase in the growth of beneficial bacteria, including bacteria that are considered probiotics and produce butyrate. This research provides insights into the potential therapeutic benefits of P. decompositum.

Breath hydrogen concentration measurement is a valuable tool for assessing the intestinal environment; however, few epidemiological studies have investigated the relationship between exhaled hydrogen and gut microbiota in healthy subjects. This study aimed to epidemiologically elucidate the relationships between exhaled hydrogen, gut microbiota, and nutrient intake in healthy residents of the Iwaki area of Hirosaki City, Aomori Prefecture, including those who exhaled methane. We categorized participants into low- and high-exhaled hydrogen groups based on the median exhaled hydrogen concentration of 6.13 ppm and matched background factors by propensity score matching for age, body mass index, and defecation habits. In the high exhaled hydrogen group, intestinal butyrate-producing bacteria such as Faecalibacterium, Anaerostipes, and Roseburia increased, and Bacteroides strains decreased. In addition, the group with high exhaled hydrogen concentrations had a high dietary fiber intake, and positive correlation was observed between dietary fiber intake and butyrate-producing bacteria. This trend was particularly pronounced for soluble dietary fiber. The exhaled methane concentration decreased in the higher exhaled hydrogen concentration group, and intestinal Methanobrevibacter was positively correlated with the exhaled methane concentration, although in extremely small amounts. No significant relationship was found between each nutrient intake and Methanobrevibacter strain. Measurement of the exhaled hydrogen concentration is useful for assessing the intestinal environment associated with nutritional intake. However, methane gas production was not changed by dietary intake, suggesting that intervention with prebiotics may be necessary.

An altered gut microbiota is considered to be an environmental factor contributing to the pathogenesis of various diseases, including metabolic disorders. In this study, we identified changes in the composition of the fecal microbiota of Mexican individuals with prediabetes and analyzed their influences on variables related to this metabolic disorder. Bacterial DNA was extracted from feces of normoglycemic and prediabetes individuals, followed by sequencing of the V4 16S rDNA. Clinical variables were correlated with bacterial abundance and diversity indexes. LEfSe analysis was used to identify relevant bacteria in normoglycemic and prediabetes individuals. Relationships between bacterial clusters and clinical data were assessed with weighted correlation network analysis (WGCNA). Bacterial diversity was positively correlated with anthropometric variables in the control group, while in individuals with prediabetes, it was negatively correlated with the insulin concentration and homeostatic model assessment of insulin resistance (HOMA-IR). We also observed that the microbiota in prediabetes individuals had a higher prevalence of Ralstonia and was enriched with bacteria belonging to the family Lachnospiraceae, as well as Eubacterium biforme and Gemmiger formicilis, while in controls, we found higher abundances of Coprococcus and Bifidobacterium bifidum (abs(linear discriminant analysis (LDA) score) >2). These results identify changes in the microbiota in Mexican adults with prediabetes. Remarkably, the genus Ralstonia was only found in prediabetes individuals. Higher insulin concentrations and HOMA-IR in those individuals were correlated with lower microbiota diversity.

The human gut microbiota plays a crucial role in overall health, impacting various diseases, including autism spectrum disorder (ASD). This study explores the relationship between gut microbiota changes and ASD by analyzing microbial compositions and abundances of 692 gut microbiota samples using public 16S rRNA sequencing datasets. Data preprocessing included normalization and redundancy reduction, retaining 367 microbial features. A machine learning model was then developed to predict ASD, utilizing feature-selected random forest algorithms that showed superior performance in both training and independent test sets. Identified microbial features with high correlation to ASD included Clostridiales bacterium VE202-08, Solobacterium moorei gene, and other features. The findings suggest that modulating the gut microbiota composition could mitigate ASD risk or alleviate symptoms. These insights pave the way for novel ASD diagnostic methods through microbiota analysis, although further research is required to validate these possibilities. This study offers a new perspective on the etiology and progression of ASD and proposes potential predictive tools for its diagnosis.

The oral administration of living Limosilactobacillus reuteri (formerly Lactobacillus reuteri) ATCC PTA 6475 cells has been shown preliminarily to prevent obesity in diet-derived obese mice and to act to ameliorate the decline in serum testosterone in old male mice. Through a clinical trial comprising a single-arm open-label pilot study in which all subjects received the same intervention, the present study aimed to evaluate whether L. reuteri ATCC PTA 6475 cells can also ameliorate the decline in serum testosterone levels in senior citizens and explore how the strain changes the intestinal microbiota. The trial was conducted with 10 eligible subjects (aged 50–69) at Hiroshima University from January to April 2024. They were instructed to take two capsules that contained a total of 1.0 × 10¹⁰ living lyophilized cells of ATCC PTA 6475 strain every day. After the 12 weeks, although remarkable changes in sex hormones were not observed, significant decreases were observed in body fat percentage, blood pressure, and some inflammation-related parameters. In addition, analysis of the fecal microbiota indicated that intake of ATCC PTA 6475 cells significantly increased the relative abundance of the genera Butyricimonas, Holdemania, and Odoribacter, which have been reported to contribute to the amelioration of obesity phenotypes. In conclusion, although the present study was carried out as a pilot study with only 10 subjects, making a placebo-controlled study necessary in the future, it demonstrates the probiotic potential of the ATCC PTA 6475 strain.

Rutin is a functional compound with both antioxidant and anti-cancer properties. The hydrolysis of rutin glycosides by intestinal bacteria is important for rutin absorption. We isolated Enterococcus sp. rutin_18, an intestinal bacterium that can convert rutin to quercetin, and investigated the possibility of Enterococcus sp. rutin_18-mediated rutin conversion to quercetin in vivo using mono-associated mice. We compared the plasma and cecal quercetin levels in rutin-metabolizing Enterococcus sp. rutin_18 mono-associated (Entero) and germ-free (GF) mice fed a rutin-supplemented diet. The plasma quercetin, isorhamnetin, and tamarixetin concentrations were significantly higher in the Entero mice than in the GF mice. The cecal rutin concentration was significantly lower in the Entero mice than in the GF mice (p<0.001). We found that Enterococcus sp. rutin_18 converted rutin to quercetin in the Entero mice. We infer that the Enterococcus sp. rutin_18 used in this study is an important intestinal bacterium that converts rutin to quercetin.

Soybean-related pollen-food allergy syndrome (PFAS) is a food allergy triggered by birch or alder pollen-specific immunoglobulin E, which cross-reacts with soybean proteins homologous to pollen proteins. Although soybean-related PFAS generally causes mild symptoms, some individuals develop severe symptoms, including anaphylaxis, especially after consuming soymilk. This study attempted to reduce the risk of allergy by fermenting soymilk with Lacticaseibacillus paracasei strain Shirota (YIT 9029, LcS). The levels of Gly m 4, which causes soybean-related PFAS, in soymilk and fermented soymilk were analyzed using enzyme-linked immunosorbent assay (ELISA) and western blotting. Reactions to soymilk and fermented soymilk were evaluated in patients with soybean-related PFAS using skin prick tests to compare allergic risks. Gly m 4 levels in the soluble fraction of fermented soymilk were significantly lower than those in soymilk. The reduction in Gly m 4 levels was associated with alterations in the fermentation process, including pH reduction. Additionally, compared with soymilk, fermented soymilk reduced skin prick test reactions in patients with soybean-related PFAS. In conclusion, fermenting soymilk with LcS reduced soluble Gly m 4 levels and alleviated allergic reactions associated with soybean-related PFAS. This study demonstrates the potential of fermented soymilk as a safe and effective alternative for individuals with soybean-related PFAS.

Depression is one of the common psychiatric disorders, and it has been reported that the imbalance in the microbiota-gut-brain (MGB) axis contributes to the pathogenesis of depression. Milk fat globule membrane (MFGM) can impact the gut-brain axis by regulating the intestinal flora and metabolite production. The aim of this study was to investigate whether MFGM could ameliorate depressive-like behaviors induced by chronic unpredictable mild stress (CUMS) and further elucidate the potential mechanism through a fecal microbiota transplantation (FMT) experiment. Male Sprague-Dawley rats were provided with an MFGM diet for 5 weeks after the induction with CUMS. Depressive-like behaviors were assessed, and the levels of neurotransmitters, neuroendocrine hormones, microbiota, short-chain fatty acids (SCFAs), and tight junction proteins, including occludin and zonula occludens-1 (ZO-1), were measured. It was revealed that MFGM could alleviate the depressive-like behaviors in CUMS rats. MFGM up-regulated the expression of occludin and ZO-1 and ameliorated intestine pathological changes in CUMS rats. Moreover, MFGM increased the levels of 5-hydroxytryptamine (5-HT), dopamine (DA), and norepinephrine and decreased the levels of neuroendocrine hormones in CUMS rats. Furthermore, it was confirmed that the concentrations of SCFAs, DA, 5-HT, and tight junction proteins significantly increased in the recipient rats that were inoculated with the fecal microbiota from the rats after MFGM treatment. These findings demonstrated that MFGM could alleviate depressive-like behaviors in CUMS rats and was possibly associated with modulation of the gut microbiota and up-regulation of SCFAs and monoamine neurotransmitters.

Immunoglobulin A (IgA) plays a key role in mucosal immunity. We investigated the IgA-inducing capacity of heat-killed Bifidobacterium bifidum G9-1 (BBG9-1) using Peyer’s patch (PP)-derived cells. Heat-killed BBG9-1, but not its culture supernatant, significantly enhanced IgA secretion and cell aggregation. Compared with other Gram-positive bacteria, BBG9-1 showed a stronger IgA-inducing effect. Component analysis revealed that peptidoglycan (PG), but not lipoteichoic acid (LTA), isolated from BBG9-1 significantly stimulated IgA secretion. These findings suggest that PG from BBG9-1 is a key factor in IgA induction, supporting its potential application in modulating mucosal immune responses.

The authors would like to apologize for not adding support information for the fund items of this work.

This work was supported by the Science and Technology Research Project of the Education Department of Jilin Province (No. JJKH20240103KJ).

This work was supported by the Wellness Science and Technology Capacity Improvement Project of the Health Commission of Jilin Province (No. 2023JC029).