Lignans and gut microbiota: An interplay revealing potential health implications

Plant polyphenols are a broad group of bioactive compounds characterized by different chemical and structural properties, low bioavailability, and several in vitro biological activities. Among these compounds, lignans (a non-flavonoid polyphenolic class found in plant foods for human nutrition) have been recently studied as potential modulators of the gut–brain axis. In particular, gut bacterial metabolism is able to convert dietary lignans into therapeutically relevant polyphenols (i.e., enterolignans), such as enterolactone and enterodiol. Enterolignans are characterized by various biologic activities, including tissue-specific estrogen receptor activation, together with anti-inflammatory and apoptotic effects. However, variation in enterolignans production by the gut microbiota is strictly related to both bioaccessibility and bioavailability of lignans through the entire gastrointestinal tract. Therefore, in this review, we summarized the most important dietary source of lignans, exploring the interesting interplay between gut metabolites, gut microbiota, and the so-called gut–brain axis.Fil: Senizza, Alice. Catholic University Of The Sacred Heart, Piacenza, ; ItaliaFil: Rocchetti, Gabriele. Catholic University Of The Sacred Heart, Piacenza, ; ItaliaFil: Mosse, Juana Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Patrone, Vania. Catholic University Of The Sacred Heart, Piacenza; ItaliaFil: Callegari, Maria Luisa. Catholic University Of The Sacred Heart, Piacenza, ; ItaliaFil: Morelli, Lorenzo. Catholic University Of The Sacred Heart, Piacenza, ; ItaliaFil: Lucini, Luigi. Catholic University Of The Sacred Heart, Piacenza, ; Itali

Dataset on the effects of different pre-harvest factors on the metabolomics profile of lettuce (Lactuca sativa l.) leaves

The study of the relationship between cultivated plants and environmental factors can provide information ranging from a deeper understanding of the plant biological system to the development of more effective management strategies for improving yield, quality, and sustainability of the produce. In this article, we present a comprehensive metabolomics dataset of two phytochemically divergent lettuce (Lactuca sativa L.) butterhead varieties under different growing conditions. Plants were cultivated in hydroponics in a growth chamber with ambient control. The pre-harvest factors that were independently investigated were light intensity (two levels), the ionic strength of the nutrient solutions (three levels), and the molar ratio of three macroelements (K, Mg, and Ca) in the nutrient solution (three levels). We used an untargeted, mass-spectrometry-based approach to characterize the metabolomics profiles of leaves harvested 19 days after transplant. The data revealed the ample impact on both primary and secondary metabolism and its range of variation. Moreover, our dataset is useful for uncovering the complex effects of the genotype, the environmental factor(s), and their interaction, which may deserve further investigation

Trichoderma spp.-mediated mitigation of heat, stress, and their combination on the Arabidopsis thaliana holobiont: a metabolomics and metabarcoding approach

IntroductionThe use of substances to increase productivity and resource use efficiency is now essential to face the challenge of feeding the rising global population with the less environmental impact on the ecosystems. Trichoderma-based products have been used as biopesticides, to inhibit pathogenic microorganisms, and as biostimulants for crop growth, nutrient uptake promotion, and resistance to abiotic stresses.MethodsIn this work, plant metabolomics combined with roots and rhizosphere bacterial metabarcoding were exploited to inspect the performance of Trichoderma spp. biostimulants on Arabidopsis thaliana under drought, heat and their combination and its impact on plant holobiont.Results and discussionAn overall modulation of N-containing compounds, phenylpropanoids, terpenes and hormones could be pointed out by metabolomics. Moreover, metabarcoding outlined an impact on alpha and beta-diversity with an abundance of Proteobacteria, Pseudomonadales, Burkholderiales, Enterobacteriales and Azospirillales. A holobiont approach was applied as an integrated analytical strategy to resolve the coordinated and complex dynamic interactions between the plant and its rhizosphere bacteria using Arabidopsis thaliana as a model host species

Foliar application of different vegetal-derived protein hydrolysates distinctively modulates tomato root development and metabolism

Despite the scientific evidence supporting their biostimulant activity, the molecular mechanism(s) underlying the activity of protein hydrolysates (PHs) and the specificity among different products are still poorly explored. This work tested five different protein hydrolysates, produced from different plant sources using the same enzymatic approach, for their ability to promote rooting in tomato cuttings following quick dipping. Provided that all the different PHs increased root length (45\u201393%) and some of them increased root number (37\u201356%), untargeted metabolomics followed by multivariate statistics and pathway analysis were used to unravel the molecular processes at the basis of the biostimulant activity. Distinct metabolomic signatures could be found in roots following the PHs treatments. In general, PHs shaped the phytohormone profile, modulating the complex interaction between cytokinins and auxins, an interplay playing a pivotal role in root development, and triggered a down accumulation of brassinosteroids. Concerning secondary metabolism, PHs induced the accumulation of aliphatic glucosinolates, alkaloids, and phenylpropanoids, potentially eliciting crop resilience to stress conditions. Here, we confirm that PHs may have a hormone-like activity, and that their application can modulate plant growth, likely interfering with signaling processes. Noteworthy, the heterogenicity of the botanical origin supported the distinctive and peculiar metabolomic responses we observed across the products tested. While supporting their biostimulant activity, these findings suggest that a generalized crop response to PHs cannot be defined and that specific effects are rather to be investigated

Linoleic acid induces metabolic stress in the intestinal microorganism Bifidobacterium breve DSM 20213

Despite clinical and research interest in the health implications of the conjugation of linoleic acid (LA) by bifidobacteria, the detailed metabolic pathway and physiological reasons underlying the process remain unclear. This research aimed to investigate, at the molecular level, how LA affects the metabolism of Bifidobacterium breve DSM 20213 as a model for the well-known LA conjugation phenotype of this species. The mechanisms involved and the meaning of the metabolic changes caused by LA to B. breve DSM 20213 are unclear due to the lack of comprehensive information regarding the responses of B. breve DSM 20213 under different environmental conditions. Therefore, for the first time, an untargeted metabolomics-based approach was used to depict the main changes in the metabolic profiles of B. breve DSM 20213. Both supervised and unsupervised statistical methods applied to the untargeted metabolomic data allowed confirming the metabolic changes of B. breve DSM 20213 when exposed to LA. In particular, alterations to the amino-acid, carbohydrate and fatty-acid biosynthetic pathways were observed at the stationary phase of growth curve. Among others, significant up-regulation trends were detected for aromatic (such as tyrosine and tryptophan) and sulfur amino acids (i.e., methionine and cysteine). Besides confirming the conjugation of LA, metabolomics suggested a metabolic reprogramming during the whole growth curve and an imbalance in redox status following LA exposure. Such redox stress resulted in the down-accumulation of peroxide scavengers such as low-molecular-weight thiols (glutathione- and mycothiol-related compounds) and ascorbate precursors, together with the up-accumulation of oxidized (hydroxy- and epoxy-derivatives) forms of fatty acids. Consistently, growth was reduced and the levels of the oxidative stress marker malondialdehyde were higher in LA-exposed B. breve DSM 20213 than in the control

Use of biostimulants to counteract the stresses related to climate change in plant

Lo scopo della presente tesi di dottorato era valutare l'impatto dello stress combinato (alte temperature e siccità) in Arabidopsis thaliana e confrontare i singoloi stress con la loro combinazione per rivelare possibili effetti e interazioni additive. Gli studi di stress combinati sono raramente affrontati da una prospettiva molecolare nonostante la risposta a stress combinati non corrisponde semplicemente alla somma delle risposte a ciascuno stress che possono avere componenti additive o opposte. Queste risposte includono cambiamenti morfologici, fisiologici, biochimici e molecolari e l'attivazione di vie di segnalazione che coinvolgono fitormoni, trasduttori di segnale e regolatori trascrizionali. Nella seconda parte, è stata anche testata la performance di Trichoderma (biostimolante) in condizioni di siccità, calore, e loro combinazione, e il suo impatto sulle relazioni pianta-microrganismi. L'applicazione di funghi come Trichoderma può essere benefica, in quanto il fungo può stabilire relazioni simbiotiche con una pianta ospite ed influenzarne la crescita, la germinazione dei semi e la fioritura. Il fungo inoltre rilascia metaboliti secondari che inibiscono la crescita dei patogeni, aumentano la tolleranza allo stress e inducono la sintesi e l'accumulo di enzimi, la produzione di molecole come i fitormoni di sostanze con attività simile. Inoltre, i metaboliti secondari prodotti dalle piante, fungono da segnale nelle interazioni pianta-microrganismi, influenzando la composizione del microbioma vegetale. Questa relazione è dinamica e coinvolge diversi scambi bidirezionali: alcuni microrganismi regolano la produzione di metaboliti secondari e queste molecole bioattive modellano il microbioma del suolo. Queste interazioni pianta-microrganismi avvengono durante tutte le fasi del ciclo di vita e insieme all'interazione con l'ambiente e altri fattori biotici modellano la composizione del microbiota vegetale. A tal fine, è stata utilizzata una combinazione di metabolomica delle piante e metabarcoding batterico della radice e della rizosfera per svelare gli effetti a livello di "holobiont" vegetale. La combinazione di diversi approcci offre una visione completa delle interazioni che influenzano i passaggi dal genotipo al fenotipo, fornendo un profilo globale per comunità più diversificate.The aim of the present PhD thesis was to evaluate the impact of combined heat and drought stress in Arabidopsis thaliana and compare the individual stress to their combination to reveal additive effects and interactions. Studies on the co-occurrence of more abiotic stresses are rarely approached from a molecular perspective and evidence suggests that the response to a combined stress does not correspond simply to the sum of the responses to each stress but may have antagonistic or opposing components. These responses include morphological, physiological, biochemical, and molecular changes and the activation of signaling pathways that involves phytohormones, signal transducers and transcriptional regulators. In the second part, was also tested the performance of Trichoderma biostimulants on Arabidopsis thaliana under drought, heat and their combination and its impact on plant holobiont. The application of Trichoderma spp. as biostimulant is well recognized. These fungi can establish symbiotic relationships with a host plant and other than the effect on growth, seed germination and flowering, the fungus releases secondary metabolites that inhibit the growth of plant pathogens, increase the tolerance to stress and induce the synthesis and the accumulation of enzymes, the production of secondary metabolites, signaling molecules i.e phytohormones and the release of substances with auxin-like activity. Indeed, the secondary metabolites produced by plants act as signals in plant-microbes interactions, affecting the composition of the plant microbiome. This relationship is dynamic and involves several bi-directional exchanges: some microorganisms adjust the production of secondary metabolites, and these bioactive molecules shape the soil microbiome. These plants-microbes interactions continue during all the life cycle stages and together with interaction with environment and other biotic inhabitants shape the composition of plant microbiota. For these purposes, a combination of plant metabolomics and root and rhizosphere bacterial metabarcoding were used to unravel effects at the plant holobiont level. Combining different approaches offers a comprehensive view of interactions influencing the steps from genotype to phenotype, providing global profiling for more diversified communities

OMICS APPROACH TO INVESTIGATE THE ROLE OF ENTERIC BACTERIA IN METABOLIZING FOOD COMPONENTS

In questa tesi di Dottorato, l’obiettivo era valutare l’impatto di diversi ingredienti alimentari sul metabolismo di alcuni batteri intestinali e viceversa, mediante l’applicazione di tecniche omiche. Utilizzando le tecniche di metabolomica e trascrittomica, è stata studiata la risposta all’acido linoleico del ceppo Bifidobacterium breve DSM 20213. Utilizzando un approccio combinato di metagenomica e metabolomica, è stato possibile studiare le modifiche a carico del microbiota intestinale, del profilo fenolico e degli acidi grassi, in biscotti senza glutine (a base di erba medica) durante digestione e fermentazione in vitro. Inoltre, è stato valutato come alcuni batteri potessero interferire negativamente su una terapia farmacologica a base di Diclofenac, un farmaco usato per alcune patologie intestinali. Per questo tipo di studio è stata utilizzata la spettrometria di massa ad alta risoluzione, che ha consentito di ipotizzare un coinvolgimento dell’enzima batterico β-glucuronidasi. Una sola tecnica omica, seppure di ultima generazione, non permette di valutare tutte le modificazioni del microbiota intestinale data la complessità dei fattori coinvolti. Per questa ragione, integrare più approcci omici potrebbe risultare una buona strategia per analizzare il reale impatto del microbiota sulla salute dell’ospite. Questo permetterebbe di valutare le interazioni microbiota-ospite, i principali metabolismi e le interconnessioni tra gruppi batterici coinvolti nella risposta ad uno stimolo esterno come l’assunzione di particolari ingredienti con l’alimentazione.The aim of the present PhD thesis was to explore the metabolic response of intestinal bacteria to food components by using ‘omics’ approaches. In particular, the first part of this thesis was focused on the effect of linoleic acid on Bifidobacterium breve DSM 20213 strain. Firstly, an untargeted metabolomics-based approach was used to explore the primary changes in metabolic profile of this strain grown in presence of linoleic acid. Secondly, the gene expression of B. breve DSM 20213 induced by linoleic acid exposure was investigated. Integrated use of metabolomics/transcriptomics was applied to better understand the response mechanisms to linoleic acid stress. In the third part of the thesis, using a combination of metagenomics and metabolomics, the in vitro large intestine fermentation of gluten-free rice cookies containing alfalfa seed was investigated. In the last part of my PhD, the negative effect of β-glucuronidase producing bacteria was evaluated by means of qualitative high-resolution mass spectrometry. Based on my experience there is not a gold standard approach for evaluating a complex environment such as the gastrointestinal tract. For this reason, an integrated use of different techniques should be mandatory to have an accurate framework of gut microbiota composition, its potential metabolic network and the impact on the host physiology and health

Effects of Linoleic Acid on Gut-Derived Bifidobacterium breve DSM 20213: A Transcriptomic Approach

Bacterial production of conjugated linoleic acid (CLA) has recently received great attention because of the potential health benefits of this fatty acid. Linoleic acid (LA) can be converted to CLA by several microorganisms, including bifidobacteria, possibly as a detoxification mechanism to avoid the growth inhibition effect of LA. In the present in vitro study, we investigated the gene expression landscape of the intestinal strain Bifidobacterium breve DSM 20213 when exposed to LA. Transcriptomic analysis using RNA-seq revealed that LA induced a multifactorial stress response in the test strain, including upregulation of genes involved in iron uptake and downregulation of genes involved in sugar and oligopeptide transport. We also observed reduced transcription of genes involved in membrane and pili biosynthesis. The upregulation of iron uptake was not related to any putative ability of LA to chelate Fe2+, but was somewhat linked to stress response. Furthermore, we demonstrated that LA increased reactive oxygen species (ROS) production in bacterial cells, activating an oxidative stress response. This response was proved by thioredoxin reductase transcription, and was primarily evident among bacteria cultured in the absence of cysteine. This is the first report of the potential mechanisms involved in bacterial LA transport and stress response in B. breve

Storia di Trieste abbinata a quella dell'Istria

Università degli Studi di Triest