Impact of Food-Derived Bioactive Compounds on Intestinal Immunity

Effect of allyl-isothiocyanate on survival and antimicrobial peptide expression following oral bacterial infections in Drosophila melanogaster

Since infections with antibiotic-resistant bacteria cause increasing problems worldwide, the identification of alternative therapies is of great importance. Plant-derived bioactives, including allyl-isothiocyanate (AITC), have received attention for their antimicrobial properties. The present study therefore investigates the impact of AITC on survival and antimicrobial peptide (AMP) levels in Drosophila melanogaster challenged with the fly pathogenic bacteria Pectobacterium carotovorum subsp. carotovorum and Leuconostoc pseudomesenteroides. AITC, a sulfur-containing compound derived from glucosinolates, exhibits antimicrobial properties and has been suggested to modulate AMP expression. By using D. melanogaster, we demonstrate that AITC treatment resulted in a concentration-dependent decrease of survival rates among female flies, particularly in the presence of the Gram-negative bacterium Pectobacterium carotovorum subsp. carotovorum, whereas AITC did not affect survival in male flies. Despite the ability of isothiocyanates to induce AMP expression in cell culture, we did not detect significant changes in AMP mRNA levels in infected flies exposed to AITC. Our findings suggest sex-specific differences in response to AITC treatment and bacterial infections, underlining the complexity of host-pathogen interactions and potential limitations of AITC as a preventive or therapeutic compound at least in D. melanogaster models of bacterial infections.

High-fat diet enhances cell proliferation and compromises intestinal permeability in a translational canine intestinal organoid model

BACKGROUND

Emerging evidence underscores the responsiveness of the mammalian intestine to dietary cues, notably through the involvement of LGR5 + intestinal stem cells in orchestrating responses to diet-driven signals. However, the effects of high-fat diet (HFD) on these cellular dynamics and their impact on gut integrity remain insufficiently understood. Our study aims to assess the multifaceted interactions between palmitic acid (PA), cell proliferation, and the intestinal epithelial barrier using a canine colonoid model. Canine models, due to their relevance in simulating human intestinal diseases, offer a unique platform to explore the molecular mechanisms underlying HFD derived intestinal dysfunction.

RESULTS

Canine colonoids were subjected to PA exposure, a surrogate for the effects of HFD. This intervention revealed a remarkable augmentation of cell proliferative activity. Furthermore, we observed a parallel reduction in transepithelial electrical resistance (TEER), indicating altered epithelium barrier integrity. While E-cadherin exhibited consistency, ZO-1 displayed a noteworthy reduction in fluorescence intensity within the PA-exposed group.

CONCLUSIONS

By employing canine intestinal organoid systems, we provide compelling insights into the impact of PA on intestinal physiology. These findings underscore the importance of considering both cell proliferative activity and epithelial integrity in comprehending the repercussions of HFDs on intestinal health. Our study contributes to a deeper understanding of the consequences of HFD on intestinal homeostasis, utilizing valuable translational in vitro models derived from dogs.

Comparative Analysis of Intestinal Inflammation and Microbiota Dysbiosis of LPS-Challenged Piglets between Different Breeds

Post-weaning diarrhea is common in piglets, causing huge economic losses worldwide. Associations between LPS challenge, intestinal inflammation, and microbiota have been reported in Duroc × Landrace × Yorkshire (DLY) crossbred pigs. However, the effects of LPS challenge in other breeds remain unclear. In the current study, we performed a comprehensive comparative analysis of the effects of LPS challenge on jejunal mucosal morphology, jejunal microbial composition, and serum indexes in two pig breeds: DLY and Heigai, an indigenous Chinese breed. The results showed that LPS caused considerable damage to the mucosal morphology, enhanced serum levels of inflammatory cytokines and the intestinal permeability index, and lowered the antioxidant capacity index. LPS challenge also changed the microbial composition and structure of the jejunum, significantly increased the abundances of Escherichia-Shigella in DLY pigs, and decreased those of Gemella and Saccharimonadales in Heigai pigs. Furthermore, LPS challenge triggered functional changes in energy metabolism and activities related to the stress response in the jejunal bacterial community, alleviating the inflammatory response in Heigai pigs. This study also revealed that Heigai pigs had a weaker immune response to LPS challenge than DLY pigs, and identified several genera related to the breed-specific phenotypes of Heigai pigs, including Gemella, Saccharimonadales, Clostridia_UCG_014, Terrisporobacter, and Dielma. Our collective findings uncovered differences between Heigai and DLY pigs in intestinal inflammation and microbiota dysbiosis induced by LPS challenge, providing a theoretical basis for unraveling the mechanism of intestinal inflammation in swine and proposing microbial candidates involved in the resistance to diarrhea in piglets.

Immunological Regulation of Gut-Tropic Immune Cells by Extracellular Vesicles

The remarkable diversity of lymphocytes, essential components of the immune system, serves as an ingenious mechanism for maximizing the efficient utilization of limited host defense resources. While cell adhesion molecules, notably in gut-tropic T cells, play a central role in this mechanism, the counterbalancing molecular details have remained elusive. Conversely, we've uncovered the molecular pathways enabling extracellular vesicles secreted by lymphocytes to reach the gut's mucosal tissues, facilitating immunological regulation. This discovery sheds light on immune fine-tuning, offering insights into immune regulation mechanisms.

Bioactive Dairy-Fermented Products and Phenolic Compounds: Together or Apart

Fermented dairy products (e.g., yogurt, kefir, and buttermilk) are significant in the dairy industry. They are less immunoreactive than the raw materials from which they are derived. The attractiveness of these products is based on their bioactivity and properties that induce immune or anti-inflammatory processes. In the search for new solutions, plant raw materials with beneficial effects have been combined to multiply their effects or obtain new properties. Polyphenols (e.g., flavonoids, phenolic acids, lignans, and stilbenes) are present in fruit and vegetables, but also in coffee, tea, or wine. They reduce the risk of chronic diseases, such as cancer, diabetes, or inflammation. Hence, it is becoming valuable to combine dairy proteins with polyphenols, of which epigallocatechin-3-gallate (EGCG) and chlorogenic acid (CGA) show a particular predisposition to bind to milk proteins (e.g., α-lactalbumin β-lactoglobulin, αs1-casein, and κ-casein). Reducing the allergenicity of milk proteins by combining them with polyphenols is an essential issue. As potential 'metabolic prebiotics', they also contribute to stimulating the growth of beneficial bacteria and inhibiting pathogenic bacteria in the human gastrointestinal tract. In silico methods, mainly docking, assess the new structures of conjugates and the consequences of the interactions that are formed between proteins and polyphenols, as well as to predict their action in the body.

Fruits and vegetables intake may be associated with a reduced odds of multiple sclerosis: a systematic review and dose-response meta-analysis of observational studies

INTRODUCTION

Multiple sclerosis (MS) is an immune-mediated condition of the central nervous system (CNS). Intake of fruits and vegetables high in vitamins, minerals, fiber, and active molecules contributes to the body's overall health, immunity, and physiological function. This study sought to review the literature and investigate the relationship between fruits and vegetables consumption and MS odds.

METHODS

In the current systematic review and meta-analysis, a systematic search of original databases from inception to 21 Dec 2022 was conducted based on the PRISMA 2020 statement. Human observational studies examining the association between fruits or vegetables consumption and MS prevalence were included if they reported and provided effect size with 95% confidence intervals (CIs).

RESULTS

The systematic review and meta-analysis included eight studies. Random effect model showed the protective effect of fruits (I2 = 81.0%, P for heterogeneity < 0.001; pooled OR = 0.52, 95%CI = 0.27, 0.97, P-value = 0.042) and vegetables consumption (I2 = 73.5%, P for heterogeneity = 0.002; pooled OR = 0.61, 95%CI = 0.38, 1.00, P-value = 0.050) on MS odds. According to a linear dose-response meta-analysis of four case-control studies, an increase of 100 grams of fruits per day reduced the odds of MS by 9% (I2 = 0.0%, P for heterogeneity = 0.77; pooled OR = 0.91, 95%CI = 0.83, 0.99, P-value = 0.021).

CONCLUSION

Consumption of fruits and vegetables may be associated with a potential protective effect against MS. However, further confirmation is required through prospective longitudinal studies and randomized clinical trials.

Senolytic and senomorphic secondary metabolites as therapeutic agents in Drosophila melanogaster models of Parkinson's disease

Drosophila melanogaster is a valuable model organism for a wide range of biological exploration. The well-known advantages of D. melanogaster include its relatively simple biology, the ease with which it is genetically modified, the relatively low financial and time costs associated with their short gestation and life cycles, and the large number of offspring they produce per generation. D. melanogaster has facilitated the discovery of many significant insights into the pathology of Parkinson's disease (PD) and has served as an excellent preclinical model of PD-related therapeutic discovery. In this review, we provide an overview of the major D. melanogaster models of PD, each of which provide unique insights into PD-relevant pathology and therapeutic targets. These models are discussed in the context of their past, current, and future potential use for studying the utility of secondary metabolites as therapeutic agents in PD. Over the last decade, senolytics have garnered an exponential interest in their ability to mitigate a broad spectrum of diseases, including PD. Therefore, an emphasis is placed on the senolytic and senomorphic properties of secondary metabolites. It is expected that D. melanogaster will continue to be critical in the effort to understand and improve treatment of PD, including their involvement in translational studies focused on secondary metabolites.

Amino Acid Analyses of Plant Foods Used in the Dietary Management of Inherited Amino Acid Disorders

A low amino acid (AA)/protein diet is the principal treatment for many inherited amino acid disorders (IMDs). Due to their low AA content, plant foods constitute an essential part of diet therapy. However, data on their AA composition are limited, which leads to an estimation of AA intake from protein content rather than an accurate calculation of true AA intake. This study describes the AA content of a total of 73 plant foods (fruits, n = 12; vegetables, n = 51; and other plant foods, n = 10), with the analysis commissioned by the UK National Society for Phenylketonuria (NSPKU) over 15 years. For all fruits and some vegetables (e.g., rocket, watercress and pea shoots), raw samples were used during analysis. All other vegetables were cooked prior to analysis to represent the usual condition of the food at the time of serving. AA analysis was performed with ion exchange chromatography. The median percentage of protein was 2.0% [0.6-5.4%] for the fruits and vegetables analysed (n = 56), although higher in vegetables than in fruits. Each of the five reported AAs (leucine, lysine, phenylalanine, tyrosine, and methionine) supplied 1-5% per g of protein content. From the heterogeneous range of plant foods analysed, the AA/protein ratios differed significantly (2-5% in fruits and 1-9% in vegetables). There was a strong correlation between the amounts of each of the five AAs in the plant foods, but only a small, moderate correlation between the protein and AA content. Overall, this study provides data on the AA content of several plant foods, which are suitable for patients treated with a low AA/protein diet, including many novel plant options. However, only a limited range of fruits and vegetables were analysed due to the high costs of analysis. Hence, more extensive studies with an increased number of plant foods prepared by different cooking methods and replicate samples are necessary, particularly to examine the relationship between the protein and AA content in depth.

Dietary-Derived Exosome-like Nanoparticles as Bacterial Modulators: Beyond MicroRNAs

There is increasing evidence that food is an important factor that influences the composition of the gut microbiota. Usually, all the attention has been focused on nutrients such as lipids, proteins, vitamins, or polyphenols. However, a pivotal role in these processes has been linked to dietary-derived exosome-like nanoparticles (DELNs). While food macro- and micronutrient composition are largely well established, there is considerable interest in these DELNs and their cargoes. In this sense, traditionally, all the attention was focused on the proteins or miRNAs contained in these vesicles. However, it has been shown that DELNs would also carry other bioactive molecules with a key role in regulating biochemical pathways and/or interactions with the host's gut microbiome affecting intracellular communication. Due to the scarce literature, it is necessary to compile the current knowledge about the antimicrobial capacity of DELNs and its possible molecular mechanisms that will serve as a starting point. For this reason, in this review, we highlight the impact of DENLs on different bacteria species modulating the host gut microbiota or antibacterial properties. It could be concluded that DELNs, isolated from both plant and animal foods, exert gut microbiota modulation. However, the presence of miRNA in the vesicle cargoes is not the only one responsible for this effect. Lipids present in the DELNs membrane or small molecules packed in may also be responsible for apoptosis signaling, inhibition, or growth promoters.

Production of benzylglucosinolate in genetically engineered carrot suspension cultures

Glucosinolates, a group of sulfur-containing specialized metabolites of the Brassicales, have attracted a lot of interest in nutrition, medicine and agriculture due to their positive health effects and their involvement in plant defense. Their biological activities and the extensive knowledge of their biosynthesis have inspired research into development of crops with enhanced glucosinolate contents as well as their biotechnological production in homologous and heterologous systems. Here, we provide proof-of-concept for transgenic suspension cultures of carrot (Daucus carota, Apiacae) as a scalable production platform for plant specialized metabolites using benzylglucosinolate as a model. Two T-DNAs carrying in total six genes of the benzylglucosinolate biosynthesis pathway from Arabidopsis thaliana as well as NPTII and BAR as selectable markers were transferred to carrot cells by Agrobacterium tumefaciens-mediated transformation. Putative transformants selected based on their kanamycin and BASTA resistances were subjected to HPLC-MS analysis. Of 79 putative transformants, 17 produced benzylglucosinolate. T-DNA-integration was confirmed for the five best producers. Callus from these transformants was used to establish suspension cultures for quantitative analysis. When grown in 60-ml-cultures, the best transformants produced roughly 2.5 nmol (g fw)^-1 benzylglucosinolate, together with up to 10 nmol (g fw)^-1 desulfobenzylglucosinolate. Only one transformant produced more benzylglucosinolate than desulfobenzylglucosinolate. The concentration of sulfate in the medium was not a major limiting factor. High production seemed to be associated with poor growth and vice versa. Therefore, future research should try to optimize medium and cultivation process and to separate growth and production phase by using an inducible promoter.

Modulation of gut microbiota: The effects of a fruits and vegetables supplement

The consumption of an optimal amount of fruits and vegetables is known to improve physical fitness and physiological body functions. Healthy eating habits, including intake of fruits and vegetables, can modify gut microbiota. This study aimed to demonstrate the effectiveness of a formulated fruit and vegetable supplement (FVS) in modulating the antioxidant capacity and the gut microbiota composition. We enrolled 30 healthy volunteer subjects, matched for age, gender, BMI, and smoking habits, and randomized them into the FVS and the placebo (PLA) groups. Among the serum vitamins, the folic acid level was significantly higher (p = 0.001) in the FVS group than in the PLA group, whereas the vitamin B2 level was significantly higher in the PLA group than in the FVS group (p = 0.028). The antioxidant capacity, measured by using the oxygen radical absorbance capacity (ORAC) method, was also slightly higher in the FVS group than in the PLA group but did not reach statistical significance. The dietary intake, assessed by 24-h recalls, did not show any significant changes after the supplementation in both the groups. The gut microbiome composition, measured by 16S rDNA sequencing, showed no difference in both alpha and beta diversities, whereas the LEfse analysis revealed a microbial shift after the treatment, with a decreased abundance of the genus Ruminococcus from the Lachnospiraceae family (p = 0.009), and the unclassified genus from the family Erysipelotrichaceae (UC36, p = 0.003) in the FVS group compared with the PLA group (confirmed by SIAMCAT analysis, AUC = 74.1%). With a minor effect, the genus Faecalibacterium and unclassified genus and family from the order Lactobacillales (UC31) were also increased in the FVS group compared with the PLA group (p = 0.0474, p = 0.0352, respectively). SCFA measurement by gas chromatography–mass spectrometry showed an increased level of 2-methylbutyrate in the FVS group compared with the PLA group (p = 0.0385). Finally, the Spearman correlation analysis showed that in the FVS group, the genus Faecalibacterium positively correlated with 2-methyl butyrate (p = 0.040). In the PLA group, none of the significant bacteria correlated with either SCFA or serum biomarkers. The network analysis confirmed the positive correlation between genus Faecalibacterium and 2-methyl butyrate. We can conclude that the FVS in healthy individuals modified the gut microbiota composition and metabolites, and it can potentially contribute to reduce the pro-inflammatory response along with the antioxidant capacity.