Roux-en-Y gastric bypass surgery in Zucker rats induces bacterial and systemic metabolic changes independent of caloric restriction-induced weight loss

Mechanisms of Roux-en-Y gastric bypass (RYGB) surgery are not fully understood. This study aimed to investigate weight loss-independent bacterial and metabolic changes, as well as the absorption of bacterial metabolites and bile acids through the hepatic portal system following RYGB surgery. Three groups of obese Zucker (fa/fa) rats were included: RYGB (n = 11), sham surgery and body weight matched with RYGB (Sham-BWM, n = 5), and sham surgery fed ad libitum (Sham-obese, n = 5). Urine and feces were collected at multiple time points, with portal vein and peripheral blood obtained at the end of the study. Metabolic phenotyping approaches and 16S rRNA gene sequencing were used to determine the biochemical and bacterial composition of the samples, respectively. RYGB surgery-induced distinct metabolic and bacterial disturbances, which were independent of weight loss through caloric restriction. RYGB resulted in lower absorption of phenylalanine and choline, and higher urinary concentrations of host-bacterial co-metabolites (e.g., phenylacetylglycine, indoxyl sulfate), together with higher fecal trimethylamine, suggesting enhanced bacterial aromatic amino acid and choline metabolism. Short chain fatty acids (SCFAs) were lower in feces and portal vein blood from RYGB group compared to Sham-BWM, accompanied with lower abundances of Lactobacillaceae, and Ruminococcaceae known to contain SCFA producers, indicating reduced bacterial fiber fermentation. Fecal γ-amino butyric acid (GABA) was found in higher concentrations in RYGB than that in Sham groups and could play a role in the metabolic benefits associated with RYGB surgery. While no significant difference in urinary BA excretion, RYGB lowered both portal vein and circulating BA compared to Sham groups. These findings provide a valuable resource for how dynamic, multi-systems changes impact on overall metabolic health, and may provide potential therapeutic targets for developing downstream non-surgical treatment for metabolic disease

Gut microbial-host metabolic interactions following bariatric surgery

Obesity has emerged as one of the major global socioeconomic healthcare burdens at present. Bariatric surgery, especially Roux-en-Y gastric bypass (RYGB) has been largely utilised to treat individual suffering from morbid obesity. In the current study, a hyperinsulinemic obese Zucker rat model was employed to study two different weight loss approaches, RYGB and caloric restriction. To understand the host metabolic-microbial cross-talk, the two major analytical platforms including nuclear magnetic resonance (NMR) spectroscopy and 16S rRNA gene Illumina MiSeq sequencing were used in companion with multivariate statistical analysis to extract useful information from data with high complexity. The aim of this study was to 1) characterise the genotype-associated metabolic and microbial fingerprints; 2) investigate the dynamic changes in biofluids from RYGB-treated or caloric restriction-treated obese Zucker rats; 3) investigate genotype-related, RYGBinduced or caloric restriction-induced metabolic profiles and microbial shifts of the luminal contents; and 4) investigate the statistical correlation between metabolites and gut microbiota following either of the weight loss treatment. Metabolic observations of portal vein and peripheral blood plasma profiles in both obese and lean Zucker rats indicated the phenotype-independent absorption of short-chain fatty acids (SCFAs), choline and trimethylamine (TMA). However, phenotype-specific urinary host-microbial co-metabolites were revealed, suggesting distinct gut microbial metabolic activities in lean and obese Zucker rats. Furthermore, metabolic alterations induced by the RYGB surgery included the enhanced production of neuroactive metabolites, branchedchain amino acid (BCAA) catabolism, aromatic amino acid metabolism with lower lipogenesis and SCFA production. Even though caloric restriction demonstrated some health benefit-related biochemical and microbial markers, its effectiveness as a resolution for metabolic syndrome, especially type-2 diabetes mellitus has not been observed in this study in spite of the significant weight reduction.Open Acces

Burkholderia pseudomallei biofilm resists Acanthamoeba sp. grazing and produces 8-O-4′-diferulic acid, a superoxide scavenging metabolite after passage through the amoeba

Abstract Burkholderia pseudomallei, an etiological agent of melioidosis is an environmental bacterium that can survive as an intracellular pathogen. The biofilm produced by B. pseudomallei is crucial for cellular pathogenesis of melioidosis. The purpose of this investigation is to explore the role of biofilm in survival of B. pseudomallei during encounters with Acanthamoeba sp. using B. pseudomallei H777 (a biofilm wild type), M10 (a biofilm defect mutant) and C17 (a biofilm-complemented strain). The results demonstrated similar adhesion to amoebae by both the biofilm wild type and biofilm mutant strains. There was higher initial internalisation, but the difference diminished after longer encounter with the amoeba. Interestingly, confocal laser scanning microscopy demonstrated that pre-formed biofilm of B. pseudomallei H777 and C17 were markedly more persistent in the face of Acanthamoeba sp. grazing than that of M10. Metabolomic analysis revealed a significant increased level of 8-O-4′-diferulic acid, a superoxide scavenger metabolite, in B. pseudomallei H777 serially passaged in Acanthamoeba sp. The interaction between B. pseudomallei with a free-living amoeba may indicate the evolutionary pathway that enables the bacterium to withstand superoxide radicals in intracellular environments. This study supports the hypothesis that B. pseudomallei biofilm persists under grazing by amoebae and suggests a strategy of metabolite production that turns this bacterium from saprophyte to intracellular pathogen

Syzygium gratum Extract Alleviates Vascular Alterations in Hypertensive Rats

Background and Objectives: Syzygium gratum (SG) is a local vegetable and widely consumed in Thailand. Previously, a strong antioxidative effect of SG extract has been reported. The effects of SG extract on hypertension have remained unknown. The effect of SG aqueous extract on blood pressure and vascular changes were examined in L-NAME-induced hypertensive rats (LHR), and its potential active constituents were also explored. Materials and Methods: Male Sprague Dawley rats were allocated to control, L-NAME (40 mg/kg/day), L-NAME + SG (100, 300, 500 mg/kg/day), or captopril (5 mg/kg/day) groups. The components of SG extract were analyzed. Results: The analysis of aqueous SG extract was carried out using HPLC-Mass spectroscopy, and phenolic compounds could be identified as predominant components which might be responsible for its antihypertensive effects observed in the LHR model (p < 0.05). Additionally, SG extract also improved vascular responses to acetylcholine and decreased vascular remodeling in LHR (p < 0.05). Enhancements of eNOS expression and plasma nitric oxide metabolite levels, and attenuation of angiotensin converting enzyme (ACE) activity and plasma angiotensin II levels were observed in the LHR group treated with SG. Moreover, SG exhibited strong antioxidant activities by reducing vascular superoxide generation and systemic malondialdehyde in LHRs. Captopril suppressed high blood pressure and alleviated vascular changes and ACE activity in LHRs, similar to those of the SG extract (p < 0.05). Conclusion: Our results suggest that the SG extract exhibited antihypertensive effects, which is relevant to alleviation of vascular dysfunction and vascular remodeling of LHRs. These effects might be mediated by phenolic compounds to inhibit ACE activity and scavenge reactive oxygen species in LHR

Evaluation of anticancer potential of Thai medicinal herb extracts against cholangiocarcinoma cell lines.

Although cholangiocarcinoma (CCA) has a low incidence globally, this is extremely high in Northeast Thailand. The lack of both early detection measures and effective therapeutic drugs is the major problem for the poor prognosis of CCA patients. Based on regional knowledge, it would be advantageous to search for effective natural phyto-products for the treatment of CCA. Cardiospermum halicacabum L., Gomphrena celosioides Mart. and Scoparia dulcis L., very well-known medicinal herbs in Asian countries, were selected for the investigation of inhibitory effects on CCA cells. Of the three different ethanolic extracts, S. dulcis L extract showed most inhibitory effects on cell growth of CCA cell lines KKU-100 and KKU-213, at percentages of 56.06 and 74.76, respectively, compared to the untreated group after treatment with 250 μg/mL of extracts for 72 hrs. At 400 and 500 μg/mL of the extracts, the inhibitory effect of KKU-213 was indicated by a significant increase in the BAX/Bcl-2 ratio and cell membrane permeability. Moreover, metabolic profiling-based screening employed in the current study revealed a significant positive association between the lignin compound and a decrease in CCA cell viability. Our study suggests, for the first time, that ESD has the ability to inhibit CCA cell growth through the induction of apoptosis

Antioxidant and Anticancer Potential of Bioactive Compounds from Rhinacanthus nasutus Cell Suspension Culture

The potential benefits of natural plant extracts have received attention in recent years, encouraging the development of natural products that effectively treat various diseases. This is the first report on establishing callus and cell suspension cultures of Rhinacanthus nasutus (L.) Kurz. A yellow friable callus was successfully induced from in vitro leaf explants on Murashige and Skoog medium supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid and 1 mg/L 1-naphthalene acetic acid. A selected friable callus line was used to establish the cell suspension culture with the same medium. The antioxidant assays showed that the leaf- and ethanolic-suspension-cultured cell (SCC) extracts exhibited high antioxidant potential. In addition, the in vitro cytotoxicity revealed by the MTT assay demonstrated potent antiproliferative effects against the oral cancer cell lines ORL-48 and ORL-136 in a dose-dependent manner. Several groups of compounds, including terpenoids, phenolics, flavonoids, quinones, and stilbenes, were identified by UHPLC–QToF–MS, with the same compounds detected in leaf and SCC extracts, including austroinulin, lucidenic acid, esculetin, embelin, and quercetin 3-(2″-p-hydroxybenzoyl-4″-p-coumarylrhamnoside). The present study suggests the value of further investigations for phytochemical production using R. nasutus cell suspension culture

1H NMR metabolic phenotyping of Dipterocarpus alatus as a novel tool for age and growth determination.

Dipterocarpus alatus belongs to Family Dipterocarpaceae that can be commonly found in Southeast Asian countries. It is a perennial plant with oval-shaped leaves and oleoresin-rich wood. It has been considered as a multipurpose plant since all parts can be practically utilized. One of the major problems for utilizing Dipterocarpus alatus is the difficulty knowing the exact age as this kind of plant is ready for multipurpose use after 20 years of age. At present, the most commonly used method for determining age of Dipterocarpus alatus is the annual ring estimation. However, this conventional method is unable to provide the high precision and accuracy of age determination due to its limitation including blurry annual rings caused by enriched oleoresin in the wood. The current study aimed to investigate the differences of 1H -NMR spectroscopy-based metabolic profiles from bark and leaf of Dipterocarpus alatus at different ages including 2, 7, 15 and 25 years. Our findings demonstrated that there is a total of 56 metabolites shared between bark and leaf. It is noticeable that bark at different ages exhibited the strongest variation and sugar or sugar derivatives that were found in higher concentrations in bark compared with those in leaf. We found that decreasing levels of certain metabolites including tagatose, 1'kestose and 2'-fucosyllactose exhibited the promising patterns. In conclusion, panel metabolites involved in the sucrose biosynthesis can precisely determine the age and growth of Dipterocarpus alatus

1H NMR metabolic profiling of Staphylococcus pseudintermedius isolated from canine uroliths

Staphylococcus pseudintermedius is a urease-producing bacteria which is a major cause of magnesium ammonium phosphate (MAP) urolithiasis in canine. A positive urolith culture is an important risk factor for MAP urolithiasis in canine. The mechanism underlying the metabolic changes of S. pseudintermedius after crystallization in artificial urine (AU) needs more defined baseline metabolic information. Therefore, we extensively investigated the metabolic changes of S. pseudintermedius extensively after crystallization in AU. A high urease activity and positive biofilm formation strain, entitled the S. pseudintermedius (SPMAP09) strain, was isolated from canine MAP uroliths, and analyzed using nuclear magnetic resonance (NMR) spectroscopy-based metabolomics. The molecular mechanism-specific metabolic phenotypes were clearly observed after crystallization in AU at day 3. The crystals induced by SPMAP09 were also confirmed and the major chemical composition identified as struvite. Interestingly, our findings demonstrated that a total of 11 identified metabolites were significantly changed. The levels of formate, homocarnosine, tyrosine, cis-aconitate, glycolate, ethyl malonate, valine and acetate level were significantly higher, accompanied with decreased levels of inosine, glucose, and threonine at day 3 compared with the initial time-point (day 0). In addition, our results exhibited that the glyoxylate and dicarboxylate metabolism was significantly related to the SPMAP09 strain at day 3 in AU. Thus, metabolic changes of the SPMAP09 strain after crystallization in AU potentially helps to explain the preliminary molecular mechanism for the crystals induced by S. pseudintermedius

Toward novel treatment against filariasis: Insight into genome-wide co-evolutionary analysis of filarial nematodes and Wolbachia.

Peer reviewed: TrueAcknowledgements: We thank Prapon Wilairat and Thanat Chookajorn for their comments on the scope of work during its initial stage. We thank David Ochou for additional insight into the use of the mirrortree approach and helpful discussion. We thank James Cotton for providing the assembly of Wolbachia of B. pahangi used in this analysis. We thank members of the Parasite Genomics team at the Wellcome Sanger Institute for their comments, discussions, and insights; in particular, we thank Matt Berriman, James Cotton, Eleanor Stanley, Martin Hunt, Hayley Bennett, and Anna Protasio. Computationally demanding data analyses were performed on high-performance computing facilities at Wellcome Sanger Institute and Khon Kaen University’s Office of Digital Technology.Infectious diseases caused by filarial nematodes are major health problems for humans and animals globally. Current treatment using anti-helminthic drugs requires a long treatment period and is only effective against the microfilarial stage. Most species of filarial nematodes harbor a specific strain of Wolbachia bacteria, which are essential for the survival, development, and reproduction of the nematodes. This parasite-bacteria obligate symbiosis offers a new angle for the cure of filariasis. In this study, we utilized publicly available genome data and putative protein sequences from seven filarial nematode species and their symbiotic Wolbachia to screen for protein-protein interactions that could be a novel target against multiple filarial nematode species. Genome-wide in silico screening was performed to predict molecular interactions based on co-evolutionary signals. We identified over 8,000 pairs of gene families that show evidence of co-evolution based on high correlation score and low false discovery rate (FDR) between gene families and obtained a candidate list that may be keys in filarial nematode-Wolbachia interactions. Functional analysis was conducted on these top-scoring pairs, revealing biological processes related to various signaling processes, adult lifespan, developmental control, lipid and nucleotide metabolism, and RNA modification. Furthermore, network analysis of the top-scoring genes with multiple co-evolving pairs suggests candidate genes in both Wolbachia and the nematode that may play crucial roles at the center of multi-gene networks. A number of the top-scoring genes matched well to known drug targets, suggesting a promising drug-repurposing strategy that could be applicable against multiple filarial nematode species