Protective effect of L-pipecolic acid on constipation in C57BL/6 mice based on gut microbiome and serum metabolomic

Long-term soy dietary fiber diet modifies the intestinal internal environment: Focus on chronic ulcerative colitis

Okara is a major by-product of soybean processing, which not only has negative impacts on the environment but also leads to resource waste. Soybean residue is rich in insoluble dietary fiber, which is known to have a positive effect on ulcerative colitis. This study aimed to investigate whether long-term consumption of high-purity soy isolate dietary fiber (HPSIDF) promotes the proliferation of beneficial intestinal substances, thereby alleviating intestinal damage caused by chronic ulcerative colitis (CUC). This study induced CUC using 2 % dextran sulfate sodium (DSS) and conducted a three-phase (9-week) intervention experiment. The study showed that long-term consumption of HPSIDF can regulate the level of inflammatory factors in mice and relieve damage to intestinal tissue. In addition, long-term intake of HPSIDF inhibited the degradation of Lactobacillus intestinalis and promoted the proliferation of Oscillospira and the production of beneficial substances such as Agmatine and Betaine, which played an important role in the maintenance of intestinal bacterial flora and the improvement of the internal environment. This study clarified that long-term intake of HPSIDF not only changes the intestinal self-properties but also promotes the proliferation of beneficial flora and metabolites, providing a solution strategy for the high-value utilization of okara.

The link between ultra-processed food consumption, fecal microbiota, and metabolomic profiles in older mediterranean adults at high cardiovascular risk

BACKGROUND

Ultra-processed food (UPF) consumption has been linked to adverse metabolic outcomes, potentially mediated by alterations in gut microbiota and metabolite production.

OBJECTIVE

This study aims to explore the cross-sectional and longitudinal associations between NOVA-classified UPF consumption, fecal microbiota, and fecal metabolome in a population of Mediterranean older adults at high cardiovascular risk.

METHODS

A total of 385 individuals, aged between 55 and 75 years, were included in the study. Dietary and lifestyle information, anthropometric measurements, and stool samples were collected at baseline and after 1-year follow-up. Fecal microbiota and metabolome were assessed using 16 S rRNA sequencing and liquid chromatography-tandem mass spectrometry, respectively.

RESULTS

At baseline, higher UPF consumption was associated with lower abundance of Ruminococcaceae incertae sedis (β = - 0.275, P = 0.047) and lower concentrations of the metabolites propionylcarnitine (β = - 0.0003, P = 0.013) and pipecolic acid (β = - 0.0003, P = 0.040) in feces. Longitudinally, increased UPF consumption was linked to reduced abundance of Parabacteroides spp. after a 1-year follow-up (β = - 0.278, P = 0.002).

CONCLUSIONS

High UPF consumption was associated with less favorable gut microbiota and metabolite profiles, suggesting a possible link to reduced short-chain fatty acid (SCFA) production, altered mitochondrial energy metabolism, and impaired amino acid metabolism. These findings support the reduction of UPF consumption and the promotion of dietary patterns rich in fiber for better gut health. Further research is needed to confirm these associations and clarify the underlying mechanisms.

TRIAL REGISTRATION

ISRCTN89898870 ( https://doi.org/10.1186/ISRCTN89898870 ).

Comprehensive Expression Profiles of mRNAs, LncRNAs, and CircRNAs in the Colon Specimens of Patients with Slow Transit Constipation

Slow transit constipation (STC) is a complication of depression that can negatively impact patient prognosis and quality of life. Nonetheless, the pathogenesis of STC is unclear. In this work, colon tissues from STC and non-STC patients were utilized to determine transcriptome expression patterns (messenger ribonucleic acids [mRNAs], Long noncoding RNAs [lncRNAs], and Circular RNAs [circRNAs]) via high-throughput sequencing. We found that 4430 mRNAs, 984 lncRNAs, and 2152 circRNAs exhibited substantial variations in expression patterns in the colon tissues of STC and non-STC patients. Next, we constructed a protein-protein interaction network and identified three significant elements, namely, POLR2B, SRSF1, and SUMO1, which attracted our interest. Utilizing the data of 6 upregulated circRNAs and 10 downregulated circRNAs, we created a competing endogenous RNA network. Subsequently, we found that hsa_circ_0000994 and hsa_circ_0008699 were significantly enriched in the upregulated and downregulated networks, respectively. The coexpression network analysis suggested that circRNAs and lncRNAs might exert control over mRNAs by influencing the neural functions of STC. According to the results of the integrated circRNA-miRNA-mRNA network, circRNA-regulated mRNAs were linked to both the transforming growth factor-β (TGF-β) and Notch signaling pathways. Our findings could provide new perspectives for identifying potential prognostic markers in STC. Targeting SUMO1 may present a promising approach to address colonic motility disorders in STC therapy.

Electroacupuncture alleviates functional constipation by upregulating host-derived miR-205-5p to modulate gut microbiota and tryptophan metabolism

Electroacupuncture (EA) has shown promise as a treatment for Functional constipation (FC), with growing evidence suggesting it may enhance gut motility. MicroRNAs (miRNAs) serve as key regulatory molecules mediating host-microbiota interactions. However, the specific fecal miRNAs regulating microbiota composition and metabolism in EA-treated constipated mice, along with their key targets, remain unidentified. We examined fecal microbiome composition, metabolism, and colonic miRNA expression in loperamide-induced constipated mice and EA-treated mice to identify differentially expressed miRNAs and assess their relationships with microbial abundance, metabolism, and gut motility. An antibiotic cocktail and adeno-associated virus were employed to interfere with the gut microbiota and target miRNA in vivo, thereby validating the proposed mechanism. Our results indicate that miR-205-5p, significantly upregulated in fecal and colonic tissues of EA-treated constipated mice, promotes intestinal motility in a microbiome-dependent manner. Specifically, EA promoted the growth of Lactobacillus reuteri, enriched in the feces of constipation-recovered mice, through host-derived miR-205-5p regulation. Furthermore, Lactobacillus reuteri and its tryptophan metabolites (indole-3-acetamide, indole-3-acetic acid, and indole-3-carboxaldehyde) alleviated loperamide-induced constipation. These findings underscore the pivotal role of host-derived miR-205-5p in modulating microbial composition and tryptophan metabolites to enhance intestinal motility through EA.

Carrot-Derived Rhamnogalacturonan-I Consistently Increases the Microbial Production of Health-Promoting Indole-3-Propionic Acid Ex Vivo

BACKGROUND

Using dietary interventions to steer the metabolic output of the gut microbiota towards specific health-promoting metabolites is often challenging due to interpersonal variation in treatment responses.

METHODS

In this study, we combined the ex vivo SIFR® (Systemic Intestinal Fermentation Research) technology with untargeted metabolite profiling to investigate the impact of carrot-derived rhamnogalacturonan-I (cRG-I) on ex vivo metabolite production by the gut microbiota of 24 human adults.

RESULTS

The findings reveal that at a dose equivalent to 1.5 g/d, cRG-I consistently promoted indole-3-propionic acid (IPA) production (+45.8% increase) across all subjects. At a dose equivalent to 0.3 g/d, increased IPA production was also observed (+14.6%), which was comparable to the effect seen for 1.5 g/d inulin (10.6%). IPA has been shown to provide protection against diseases affecting the gut and multiple organs. The Pearson correlation analysis revealed a strong correlation (R = 0.65, padjusted = 6.1 × 10-16) between the increases in IPA levels and the absolute levels of Bifidobacterium longum, a producer of indole-3-lactic acid (ILA), an intermediate in IPA production. Finally, the community modulation score, a novel diversity index, demonstrated that cRG-I maintained a high α-diversity which has previously been linked to elevated IPA production.

CONCLUSIONS

The results from the ex vivo SIFR® experiment mirrored clinical outcomes and provided novel insights into the impact of cRG-I on the gut microbiome function. Importantly, we demonstrated that cRG-I promotes tryptophan conversion into IPA via gut microbiome modulation, thus conferring benefits via amino acid derived metabolites extending beyond those previously reported for short chain fatty acids (SCFA) resulting from carbohydrate fermentation.

Effects of Polyvinyl Chloride (PVC) Microplastic Particles on Gut Microbiota Composition and Health Status in Rabbit Livestock

The widespread use of polyvinyl chloride (PVC) and its entry into humans and livestock is of serious concern. In our study, we investigated the impact of PVC treatments on physiological, pathological, hormonal, and microbiota changes in female rabbits. Trend-like alterations in weight were observed in the spleen, liver, and kidney in both low (P1) and high dose (P2) PVC treatment groups. Histopathological examination revealed exfoliation of the intestinal mucosa in the treated groups compared to the control, and microplastic particles were penetrated and embedded in the spleen. Furthermore, both P1 and P2 showed increased 17-beta-estradiol (E2) hormone levels, indicating early sexual maturation. Moreover, the elevated tumor necrosis factor alpha (TNF-α) levels suggest inflammatory reactions associated with PVC treatment. Genus-level analyses of the gut microbiota in group P2 showed several genera with increased or decreased abundance. In conclusion, significant or trend-like correlations were demonstrated between the PVC content of feed and physiological, pathological, and microbiota parameters. To our knowledge, this is the first study to investigate the broad-spectrum effects of PVC microplastic exposure in rabbits. These results highlight the potential health risks associated with PVC microplastic exposure, warranting further investigations in both animals and humans.

Investigating gut microbiota-blood and urine metabolite correlations in early sepsis-induced acute kidney injury: insights from targeted KEGG analyses

Background

The interplay between gut microbiota and metabolites in the early stages of sepsis-induced acute kidney injury (SA-AKI) is not yet clearly understood. This study explores the characteristics and interactions of gut microbiota, and blood and urinary metabolites in patients with SA-AKI.

Methods

Utilizing a prospective observational approach, we conducted comparative analyses of gut microbiota and metabolites via metabolomics and metagenomics in individuals diagnosed with SA-AKI compared to those without AKI (NCT06197828). Pearson correlations were used to identify associations between microbiota, metabolites, and clinical indicators. The Comprehensive Antibiotic Resistance Database was employed to detect antibiotic resistance genes (ARGs), while Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways informed on metabolic processes and microbial resistance patterns.

Results

Our study included analysis of four patients with SA-AKI and five without AKI. Significant disparities in bacterial composition were observed, illustrated by diversity indices (Shannon index: 2.0 ± 0.4 vs. 1.4 ± 0.6, P = 0.230; Simpson index: 0.8 ± 0.1 vs. 0.6 ± 0.2, P = 0.494) between the SA-AKI group and the non-AKI group. N6, N6, N6-Trimethyl-L-lysine was detected in both blood and urine metabolites, and also showed significant correlations with specific gut microbiota (Campylobacter hominis and Bacteroides caccae, R > 0, P < 0.05). Both blood and urine metabolites were enriched in the lysine degradation pathway. We also identified the citrate cycle (TCA cycle) as a KEGG pathway enriched in sets of differentially expressed ARGs in the gut microbiota, which exhibits an association with lysine degradation.

Conclusions

Significant differences in gut microbiota and metabolites were observed between the SA-AKI and non-AKI groups, uncovering potential biomarkers and metabolic changes linked to SA-AKI. The lysine degradation pathway may serve as a crucial link connecting gut microbiota and metabolites.

Bifidobacterium breve M-16V regulates the autonomic nervous system via the intestinal environment: A double-blind, placebo-controlled study

We conducted a randomized controlled trial to investigate the potential of Bifidobacterium breve M-16 V to improve mood in humans. In this evaluation, we incorporated the use of near-infrared spectroscopy (NIRS), which has been used to evaluate mood states in studies with small sample sizes. Participants were given B. breve M-16 V (20 billion cells/day) for 6 weeks, and their mood state was assessed before and after ingestion. NIRS data were collected at rest and during a mental arithmetic task (under stress). Intake of B. breve M-16 V decreased the heart rate under stress and increased levels of the GABA-like substance pipecolic acid in stool samples. In addition, B. breve M-16 V improved mood and sleep scores in participants with high anxiety levels. These results suggest that B. breve M-16 V affects the metabolites of the gut microbiota and has the potential to modulate the autonomic nervous system and to improve mood and sleep.