Adsorption of Pb2+, Cd2+, Cu2+ and Cr3+ from aqueous solutions onto titanate nanotubes (TNTs) in multiple systems was systematically studied. Particular attention was paid to competitive adsorption ...and the effect of inorganic ions. TNTs showed large adsorption capacity for the four heavy metals, with the mechanism of ion-exchange between metal ions and H+/Na+ located in the interlayers of TNTs. Binary or quaternary competitive adsorption indicated that the adsorption capacity of the four heavy metals onto TNTs followed the sequence of Pb2+ (2.64mmolg−1)≫Cd2+ (2.13mmolg−1)>Cu2+ (1.92mmolg−1)≫Cr3+ (1.37mmolg−1), which followed the reverse order of their hydration energies. Moreover, inorganic ions including Na+, K+, Mg2+ and Ca2+ inhibited the adsorption of heavy metals on TNTs, because they competed for adsorption sites, decreased the activity of heavy metal ions, and promoted the aggregation of TNTs. However, Al3+ and Fe3+ generally enhanced adsorption because the resulting hydroxyl-Al/Fe intercalated or coated TNTs could also capture metal ions. Furthermore, minor effect of inorganic ions on adsorption of Pb2+ resulted from its strong affinity to TNTs. Difficult desorption and small inhibiting effect by Na+, K+, Mg2+ and Ca2+ on adsorption of Cr3+ was due to the formed stable complex of HOCr(OTi)2 with TNTs. Present study indicated potential applications of TNTs in wastewater treatment for heavy metals.
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•Adsorption capacity was closely related to heavy-metal's hydration energy.•Pb2+ with strong affinity to TNTs led to minor effect of inorganic ions.•Difficult desorption of Cr3+ owed to the stability of complex HOCr(OTi)2.•Al3+/Fe3+ promoted adsorption due to hydroxyl-Al/Fe intercalated/coated on TNTs.•Effect of co-existing ions on heavy metal adsorption was based on ion-exchange.
The role of the food delivery matrix in probiotic performance in the intestine is not well understood. Because probiotics are often provided to consumers in dairy products, we investigated the ...contributions of milk to the health-benefiting performance of Lactobacillus casei BL23 in a dextran sulfate sodium (DSS)-induced murine model of ulcerative colitis. L. casei BL23 protected against the development of colitis when ingested in milk but not in a nutrient-free buffer simulating consumption as a nutritional supplement. Consumption of (acidified) milk alone also provided some protection against weight loss and intestinal inflammation but was not as effective as L. casei and milk in combination. In contrast, L. casei mutants deficient in DltD (lipoteichoic acid d-alanine transfer protein) or RecA (recombinase A) were unable to protect against DSS-induced colitis, even when consumed in the presence of milk. Mice fed either L. casei or milk contained reduced quantities of colonic proinflammatory cytokines, indicating that the L. casei DltD(-) and RecA(-) mutants as well as L. casei BL23 in nutrient-free buffer were effective at modulating immune responses. However, there was not a direct correlation between colitis and quantities of these cytokines at the time of sacrifice. Identification of the cecal microbiota by 16S rRNA gene sequencing showed that L. casei in milk enriched for Comamonadaceae and Bifidobacteriaceae; however, the consumption of neither L. casei nor milk resulted in the restoration of the microbiota to resemble that of healthy animals. These findings strongly indicate that probiotic strain efficacy can be influenced by the food/supplement delivery matrix.
Human tumors harbor a plethora of microbiota. It has been shown that the composition and diversity of intratumor microbiome are significantly associated with the survival of patients with pancreatic ...ductal adenocarcinoma (PDAC). However, the association in Chinese patients as well as the effect of different microorganisms on inhibiting tumor growth are unclear. In this study, we collected tumor samples resected from long-term and short-term PDAC survivors and performed 16S rRNA amplicon sequencing. We found that the microbiome in samples with different survival time were significantly different, and the differential bacterial composition was associated with the metabolic pathways in the tumor microenvironment. Furthermore, administration of
, one of the differential bacteria, induced a better tumor growth inhibition effect when combined with the immune checkpoint inhibitor anti-programmed cell death-1 (anti-PD-1) treatment in mice bearing 4T1 tumor. These results indicate that specific intratumor microbiome can enhance the anti-tumor effect in the host, laying a foundation for further clarifying the underlying detailed mechanism.
Observational studies have shown that the composition of the human gut microbiome in children diagnosed with Autism Spectrum Disorder (ASD) differs significantly from that of their neurotypical (NT) ...counterparts. Thus far, reported ASD-specific microbiome signatures have been inconsistent. To uncover reproducible signatures, we compiled 10 publicly available raw amplicon and metagenomic sequencing datasets alongside new data generated from an internal cohort (the largest ASD cohort to date), unified them with standardized pre-processing methods, and conducted a comprehensive meta-analysis of all taxa and variables detected across multiple studies. By screening metadata to test associations between the microbiome and 52 variables in multiple patient subsets and across multiple datasets, we determined that differentially abundant taxa in ASD versus NT children were dependent upon age, sex, and bowel function, thus marking these variables as potential confounders in case-control ASD studies. Several taxa, including the strains Bacteroides stercoris t__190463 and Clostridium M bolteae t__180407, and the species Granulicatella elegans and Massilioclostridium coli, exhibited differential abundance in ASD compared to NT children only after subjects with bowel dysfunction were removed. Adjusting for age, sex and bowel function resulted in adding or removing significantly differentially abundant taxa in ASD-diagnosed individuals, emphasizing the importance of collecting and controlling for these metadata. We have performed the largest (n = 690) and most comprehensive systematic analysis of ASD gut microbiome data to date. Our study demonstrated the importance of accounting for confounding variables when designing statistical comparative analyses of ASD- and NT-associated gut bacterial profiles. Mitigating these confounders identified robust microbial signatures across cohorts, signifying the importance of accounting for these factors in comparative analyses of ASD and NT-associated gut profiles. Such studies will advance the understanding of different patient groups to deliver appropriate therapeutics by identifying microbiome traits germane to the specific ASD phenotype.
While healthy gut microbiomes are critical to human health, pertinent microbial processes remain largely undefined, partially due to differential bias among profiling techniques. By simultaneously ...integrating multiple profiling methods, multi-omic analysis can define generalizable microbial processes, and is especially useful in understanding complex conditions such as Autism. Challenges with integrating heterogeneous data produced by multiple profiling methods can be overcome using Latent Dirichlet Allocation (LDA), a promising natural language processing technique that identifies topics in heterogeneous documents. In this study, we apply LDA to multi-omic microbial data (16S rRNA amplicon, shotgun metagenomic, shotgun metatranscriptomic, and untargeted metabolomic profiling) from the stool of 81 children with and without Autism. We identify topics, or microbial processes, that summarize complex phenomena occurring within gut microbial communities. We then subset stool samples by topic distribution, and identify metabolites, specifically neurotransmitter precursors and fatty acid derivatives, that differ significantly between children with and without Autism. We identify clusters of topics, deemed "cross-omic topics", which we hypothesize are representative of generalizable microbial processes observable regardless of profiling method. Interpreting topics, we find each represents a particular diet, and we heuristically label each cross-omic topic as: healthy/general function, age-associated function, transcriptional regulation, and opportunistic pathogenesis.
Childhood overweight and obesity is becoming an emerging face of malnutrition. The aims of this study were to develop fatty acid (FAs) related dietary patterns and explored the associations of FAs ...related dietary patterns with overweight and obesity among Chinese children.
An observational study was conducted on 435 children aged 4 to 7 years old in South Central China. Erythrocyte FAs composition was analyzed by gas chromatography-mass spectrometry. Diet was collected by food frequency questionnaires and dietary patterns were evaluated by reduced rank regression. The logistic regression analysis was used to exploring the association of dietary patterns with overweight and obesity.
The prevalence of overweight, obesity, and overweight or obesity were 6.52, 4.59, and 11.11% in Chinese children, respectively. Twenty five types of FAs were detected in erythrocyte of children and four FAs related dietary patterns were identified. The dietary pattern positively correlated with n-3 PUFAs, but negatively with SFAs,was characterized by high intake of fish, shrimp, crab and shellfish, leaf-off vegetable, nuts, and tubers, which have a significantly decreased overweight risk (OR = 0.580, 95%CI: 0.375 ∼ 0.895, P = 0.014).The pattern positively strong associated with n-6 PUFAs, but negatively strong with n-3 PUFAs, had high intake of snacks, leaf-off vegetable, fresh beans, and coarse cereals, which have a significantly decreased obesity risk (OR = 0.518, 95%CI: 0.325 ∼ 0.827, P = 0.006).
Four FAs related dietary patterns were identified. The dietary pattern with high intake of fish, shrimp, crab and shellfish decreased overweight risk by increasing n-3 PUFAs, and decreasing SFAs. The dietary pattern with high intake of plant food, decreased obesity risk by providing an balanced n-6/n-3 PUFAs ratio.
Metabolomic analyses of human gut microbiome samples can unveil the metabolic potential of host tissues and the numerous microorganisms they support, concurrently. As such, metabolomic information ...bears immense potential to improve disease diagnosis and therapeutic drug discovery. Unfortunately, as cohort sizes increase, comprehensive metabolomic profiling becomes costly and logistically difficult to perform at a large scale. To address these difficulties, we tested the feasibility of predicting the metabolites of a microbial community based solely on microbiome sequencing data. Paired microbiome sequencing (16S rRNA gene amplicons, shotgun metagenomics, and metatranscriptomics) and metabolome (mass spectrometry and nuclear magnetic resonance spectroscopy) datasets were collected from six independent studies spanning multiple diseases. We used these datasets to evaluate two reference-based gene-to-metabolite prediction pipelines and a machine-learning (ML) based metabolic profile prediction approach. With the pre-trained model on over 900 microbiome-metabolome paired samples, the ML approach yielded the most accurate predictions (i.e., highest F1 scores) of metabolite occurrences in the human gut and outperformed reference-based pipelines in predicting differential metabolites between case and control subjects. Our findings demonstrate the possibility of predicting metabolites from microbiome sequencing data, while highlighting certain limitations in detecting differential metabolites, and provide a framework to evaluate metabolite prediction pipelines, which will ultimately facilitate future investigations on microbial metabolites and human health.
Objective: The present study aims to measure docosahexaenoic acid (DHA) in both the plasma and erythrocyte of a child population and compares them with respect to their associations with dietary and ...metabolic risk patterns. Methods: A cross-sectional study was conducted, and a total of 435 children ages 5−7 years old were recruited. Diet information was collected using a food frequency questionnaire (FFQ). The physical indicators, blood pressure, and glycolipid metabolic indicators were determined. The plasma and erythrocyte DHA were analyzed using a gas chromatography mass spectrometer. Principal component analysis was used to identify dietary and metabolic risk patterns. Multivariate regression analyses were used to investigate the associations of DHA status with dietary and metabolic risk patterns. Results: A significant correlation between plasma and the erythrocyte DHA concentration was found (r = 0.232, p < 0.001). A diversified dietary pattern characterized that a high intake of diversified foods had a positive association with the plasma DHA level (β = 0.145, 95% CI: 0.045~0.244, p = 0.004). Children of obesity risk patterns with a high weight, pelvis breadth, BMI, upper arm circumference, and chest circumference had lower plasma DHA concentrations (OR = 0.873, 95% CI: 0.786~0.969, p = 0.011). Children with higher plasma and erythrocyte DHA concentrations were adhered to blood lipid risk patterns with high CHOL and LDL-C levels. The plasma DHA (OR = 1.271, 95% CI: 1.142~1.415, p < 0.001) had a stronger association with a blood lipid risk pattern than erythrocyte (OR = 1.043, 95% CI: 1.002~1.086, p = 0.040). Conclusions: The diversified dietary pattern had a higher plasma DHA concentration. Lower levels of plasma DHA were positively associated with obesity in children. DHA in plasma appears to be more strongly associated with blood lipid metabolism than erythrocyte. Plasma DHA may be a more sensitive bidirectional biomarker to evaluate the recently comprehensive diet intake and metabolic risk of children.
The wide application of immune checkpoint inhibitors has significantly improved the survival expectation of cancer patients. While immunotherapy brings benefits to patients, it also results in a ...series of immune-related adverse events (irAEs). Increasing evidence suggests that the gut microbiome is critical for immunotherapy response and the development of irAEs.
In this prospective study, we recruited 95 patients with advanced/unresectable gastrointestinal cancers treated with immunotherapy and report a comprehensive analysis of the association of the gut microbiome with irAEs. Metagenome sequencing was used to analyze the differences in bacterial composition and metabolic pathways of baseline fecal samples.
In summary, we identified bacterial species and metabolic pathways that might be associated with the occurrence of irAEs in gastric, esophageal, and colon cancers. Ruminococcus callidus and Bacteroides xylanisolvens were enriched in patients without severe irAEs. Several microbial metabolic pathways involved in the urea cycle, including citrulline and arginine biosynthesis, were associated with irAEs. We also found that irAEs in different cancer types and toxicity in specific organs and the endocrine system were associated with different gut microbiota profiles. These findings provide the basis for future mechanistic exploration.
Host diet is a major determinant of the composition and function of the intestinal microbiome. Less understood is the importance of diet on ingested strains with probiotic significance. We ...investigated the population dynamics of exogenous Lactobacillus plantarum and its interactions with intestinal bacteria in mice undergoing switches between high-fat, high-sugar (HFHSD) and low-fat, plant-polysaccharide rich (LFPPD) diets. The survival and persistence of ingested L. plantarum WCFS1 was significantly improved during mouse consumption of HFHSD and was negatively associated with the numbers of indigenous Lactobacillus species. Diet also rapidly changed the composition of the indigenous microbiota, but with some taxa differentially affected between HFHSD periods. L. plantarum was not integrated into indigenous bacterial community networks according to co-occurrence patterns but still conferred distinct effects on bacterial species diversity and microbiota stability largely in a diet-dependent manner. Metagenome predictions supported the premise that L. plantarum dampens the effects of diet on the microbiome. This strain also consistently altered the predicted genetic content in the distal gut by enriching for genes encoding glyosyltransferases and bile salt hydrolases. Our findings demonstrate the interactions between ingested, transient probiotic bacteria and intestinal bacterial communities and how they can differ depending on host diet.
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