Randomized placebo-controlled trial of oral tannin supplementation on COVID-19 symptoms, gut dysbiosis and cytokine response

The clinical study aim was to investigate whether a tannin-based dietary supplementation could improve the efficacy of standard-of-care treatment of hospitalized COVID-19 patients by restoring gut microbiota function. Adverse events and immunomodulation post-tannin supplementation were also investigated. A total of 124 patients receiving standard-of-care treatment were randomized to oral tannin-based supplement or placebo for a total of 14 days. Longitudinal blood and stool samples were collected for cytokine and 16S rDNA microbiome profiling, and results were compared with 53 healthy controls. Although oral tannin supplementation did not result in clinical improvement or significant gut microbiome shifts after 14-days, a reduction in the inflammatory state was evident and significantly correlated with microbiota modulation. Among cytokines measured, MIP-1α was significantly decreased with tannin treatment (p = 0.03) where it correlated positively with IL-1β and TNF- α, and negatively with stool Bifidobacterium abundance.Silvateam/Indunor SAUnited States Department of Health & Human Services National Institutes of Health (NIH) - USA NIDDK P30-DK56338 NIAID U01-AI24290 P01-AI15299

Randomized placebo-controlled trial of oral tannin supplementation on COVID-19 symptoms, gut dysbiosis and cytokine response

The clinical study aim was to investigate whether a tannin-based dietary supplementation could improve the efficacy of standard-of-care treatment of hospitalized COVID-19 patients by restoring gut microbiota function. Adverse events and immunomodulation post-tannin supplementation were also investigated. A total of 124 patients receiving standard-of-care treatment were randomized to oral tannin-based supplement or placebo for a total of 14 days. Longitudinal blood and stool samples were collected for cytokine and 16S rDNA microbiome profiling, and results were compared with 53 healthy controls. Although oral tannin supplementation did not result in clinical improvement or significant gut microbiome shifts after 14-days, a reduction in the inflammatory state was evident and significantly correlated with microbiota modulation. Among cytokines measured, MIP-1α was significantly decreased with tannin treatment (p = 0.03) where it correlated positively with IL-1β and TNF- α, and negatively with stool Bifidobacterium abundance.Silvateam/ Indunor SA and NIH grants from NIDDK P30-DK56338, NIAID U01-AI24290 and P01- AI152999MerckNivalisCubistMead JohnsonRebiotixBioFireAssembly BioScience

Why is it important to understand the nature and chemistry of tannins to exploit their potential as nutraceuticals?

Tannins comprise a large group of polyphenols that can differ widely in chemical composition and molecular weight. The use of tannins dates back to antiquity, but it is only in recent years that their potential use as nutraceuticals associated with the human diet is beginning to be exploited. Although the biological effects of these phytocomplexes have been studied for many years, there are still several open questions regarding their chemistry and biotransformation. The vastness of the molecules that make up the class of tannins has made their characterisation, as well as their nomenclature and classification, a daunting task. This review has been written with the aim of bringing order to the chemistry of tannins by including aspects that are sometimes still overlooked or should be updated with new research in order to understand the potential of these phytocomplexes as active ingredients or technological components for nutraceutical products. Future trends in tannin research should address many questions that are still open, such as determining the exact biosynthetic pathways of all classes of tannins, the actual biological effects determined by the interaction of tannins with other molecules, their metabolization, and the best extraction methods, but with a view to market requirements

Impact of gelatine coating on the performance of tannin-loaded pectin microbeads obtained through external gelation

One of the limitations of external gelation for microencapsulation is that small water-soluble compounds tend to diffuse out of the microbeads, resulting in low encapsulation efficiencies. In this work we propose a one-step approach for hydrogel microbead formation and simultaneous coating using external gelation. We explored amidated pectin as the encapsulation matrix for two different tannin-rich extracts (from chestnut and quebracho). The inclusion of tannin extracts contributed to the improvement of the structure of the microbeads through their interactions with pectin. By adding gelatine to the gelling bath, the microbeads were coated with the protein. This led to a significant increase in microencapsulation efficiency, which in some cases almost doubled compared to non-coated microbeads. Thanks to the binding of tannins with gelatine, coated microbeads loaded with the greatest amount of tannin extracts (20% w/w) presented the best retention of the bioactive compounds. A 14-days storage release study showed that these microencapsulation systems only experienced a slight loss of tannins during this period, with quebracho extract exhibiting greater retention than chestnut extract. Overall, by exploiting interactions in the pectin/tannins/gelatine ternary system, the proposed strategy for microbead production and coating in a single step allowed the development of a simple and more efficient microencapsulation approach for tannin extracts through external gelation

Enrichment of Food With Tannin Extracts Promotes Healthy Changes in the Human Gut Microbiota

This work was supported by the research project Stance4Health (contract no. 816303) from the European Commission (Research Executive Agency).The sequence data are available in the European Nucleotide Archive (ENA) under accession number PRJEB14013 (https:// www.ebi.ac.uk/ena/browser/view/PRJEB41013).This paper will form part of the doctoral thesis of SM, conducted within the context of the “Nutrition and Food Sciences Programme” at the University of GranadaThe Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmicb.2021.625782/ full#supplementary-materialFood and food bioactive components are major drivers of modulation of the human gut microbiota. Tannin extracts consist of a mix of bioactive compounds, which are already exploited in the food industry for their chemical and sensorial properties. The aim of our study was to explore the viability of associations between tannin wood extracts of different origin and food as gut microbiota modulators. 16S rRNA amplicon next-generation sequencing (NGS) was used to test the effects on the gut microbiota of tannin extracts from quebracho, chestnut, and tara associated with commercial food products with different composition in macronutrients. The different tannin-enriched and non-enriched foods were submitted to in vitro digestion and fermentation by the gut microbiota of healthy subjects. The profile of the short chain fatty acids (SCFAs) produced by the microbiota was also investigated. The presence of tannin extracts in food promoted an increase of the relative abundance of the genus Akkermansia, recognized as a marker of a healthy gut, and of various members of the Lachnospiraceae and Ruminococcaceae families, involved in SCFA production. The enrichment of foods with tannin extracts had a booster effect on the production of SCFAs, without altering the profile given by the foods alone. These preliminary results suggest a positive modulation of the gut microbiota with potential benefits for human health through the enrichment of foods with tannin extracts.European Commission European Commission Joint Research Centre 81630

Evaluation of Tannin-Delivery Approaches for Gut Microbiota Modulation: Comparison of Pectin-Based Microcapsules and Unencapsulated Extracts

The aim of this study was to investigate the impact of tannins on gut microbiota composition and activity, and to evaluate the use of pectin-microencapsulation of tannins as a potential mode of tannin delivery. Thus, pectin-tannin microcapsules and unencapsulated tannin extracts were in vitro digested and fermented, and polyphenol content, antioxidant capacity, microbiota modulation, and short-chain fatty acid (SCFA) production were analyzed. Pectin microcapsules were not able to release their tannin content, keeping it trapped after the digestive process, and are therefore not recommended for tannin delivery. Unencapsulated tannin extracts were found to exert a positive effect on the human gut microbiota. The digestion step resulted to be a fundamental requirement in order to maximize tannin bioactive effects, especially with regard to condensed tannins, as the antioxidant capacity exerted and the SCFAs produced were greater when tannins were submitted to digestion prior to fermentation. Moreover, tannins interacted differently with the intestinal microbiota depending on whether they underwent prior digestion or not. Polyphenol content and antioxidant capacity correlated with SCFA production and with the abundance of several bacterial taxaThe Irish Agricultural and Food Development Authority (Fermoy, Ireland),Plan propio de Investigación y Transferencia” of the University of Granada under program “Intensificación de la Investigación, modalidad BUniversidad de Granada/ CBUAEuropean Union’s Horizon 2020 research and innovation programme under grant agreement No 81630

Evaluation of the Effects of a Short Supplementation With Tannins on the Gut Microbiota of Healthy Subjects

This work was supported by the research project Stance4Health (Contract No. 816303) from the European Commission (Research Executive Agency).Western diet, high in fats and sugars and low in greens, contributes to dysbiosis of the gut microbiota, which can lead to a variety of chronic diseases related with inflammation. Supplementation with bioactive compounds can help to maintain a healthy eubiotic state. Thus, we performed a 4-weeks nutritional intervention on healthy volunteers to investigate whether a blend of natural tannin extracts could induce healthy changes in the microbial intestinal ecosystem. Changes in the composition and functionality of the microbiota could be observed from the first two weeks onward. 16S rRNA amplicon next-generation sequencing (NGS) revealed a significant increase in microbial diversity at the end of the intervention, as well as trends toward increases in the relative abundances of several beneficial taxa, such as Ruminococcus bicirculans, Faecalibacterium prausnitzii, Lachnospiraceae UCG 010, Lachnospiraceae NK4A136, Bacteroides thetaiotaomicron and B. uniformis. Remarkably, some of the identified taxa were also identified as responsible for an increase in the production of short-chain fatty acids (SCFAs), microbial metabolites that contribute to the modulation of the immune system and have various other anti-inflammatory functions in the gut. Taken together, these results suggest that the tannin supplementation could exert a prebiotic effect by selectively stimulating the growth and the activity of bacteria that are advantageous for the host.research project Stance4Health from the European Commission (Research Executive Agency) 81630

Pectin-Based Formulations for Controlled Release of an Ellagic Acid Salt with High Solubility Profile in Physiological Media

Among bioactive phytochemicals, ellagic acid (EA) is one of the most controversial because its high antioxidant and cancer-preventing effects are strongly inhibited by low gastrointestinal absorption and rapid excretion. Strategies toward an increase of solubility in water and bioavailability, while preserving its structural integrity and warranting its controlled release at the physiological targets, are therefore largely pursued. In this work, EA lysine salt at 1:4 molar ratio (EALYS), exhibiting a more than 400 times increase of water solubility with respect to literature reports, was incorporated at 10% in low methoxylated (LM) and high methoxylated (HM) pectin films. The release of EA in PBS at pH 7.4 from both film preparations was comparable and reached 15% of the loaded compound over 2 h. Under simulated gastric conditions, release of EA from HM and LM pectin films was minimal at gastric pH, whereas higher concentrations—up to 300 µM, corresponding to ca. 50% of the overall content—were obtained in the case of the HM pectin film after 2 h incubation at the slightly alkaline pH of small intestine environment, with the enzyme and bile salt components enhancing the release. EALYS pectin films showed a good prebiotic activity as evaluated by determination of short chain fatty acids (SCFAs) levels following microbial fermentation, with a low but significant increase of the effects produced by the pectins themselves. Overall, these results highlight pectin films loaded with EALYS salt as a promising formulation to improve administration and controlled release of the compound.European Union’s Horizon 2020 research and innovation program through the Stance4Health project (Grant No. 816303

Tannin-rich extracts improve the performance of amidated pectin as an alternative microencapsulation matrix to alginate

This work was funded by Teagasc, the Irish Agricultural and Food Development Authority (Fermoy, Ireland), by the “Plan propio de Investigaci ́on y Transferencia” of the University of Granada under both programs “Intensificaci ́on de la Investigaci ́on, modalidad B′′ and by the European Research Commission (Research Executive Agency) under the research project Stance4Health (Grant Contract N 816303) granted to Jos ́e A. Rufi ́an-Henares.Microencapsulation of tannin extracts through extrusion-gelation method was performed comparing two alter- native encapsulation matrices: alginate and amidated pectin. The microstructure of the generated microbeads was studied, as well as their microencapsulation efficiency and release properties. Overall, pectin-based beads performed better than their alginate-based counterparts. This, combined with a greater incorporation of tannins in the feed formulations led to a higher tannin load in the final beads. The best microencapsulation efficiency was given by pectin microbeads loaded with 10% tannin extract (w/w), but the final tannin content could be further increased by adding a 20% (w/w) concentration of the extracts. During a 14-days storage, only a marginal loss of tannins was recorded for pectin-based microbeads. The results reveal that great potential exists in producing pectin-based microbeads in presence of tannins, which allow better loading capacities and improving structural properties, thanks to the interactions between the tannins and the amidated polysaccharide.Teagasc, the Irish Agricultural and Food Development Authority (Fermoy, Ireland)Plan propio de Investigación y Transferencia” of the University of Granada under both programs “Intensificación de la Investigación, modalidad BEuropean Research Commission (Research Executive Agency) under the research project Stance4Health (Grant Contract N 816303

Monitoring of a micro-smart grid: Power consumption data of some machineries of an agro-industrial test site

For the management of a (micro)-smart grid it is important to know the patters of the load profiles and of the generators. In this article the power consumption data obtained through a monitoring activity developed on a micro-smart grid in an agro-industrial test-site are presented. In particular, this reports the synthesis of the monitoring results of 5 loads (5 industrial machineries for crop micronization, corncob crashing and other similar processes). How these data were used within a monitoring and managing scheme of a micro-smart grid can be found in (E. Fabrizio, V. Branciforti, A. Costantino, M. Filippi, S. Barbero, G. Tecco, P. Mollo, A. Molino, 2017) [1]. The data can be useful for other researchers in order to create benchmarks of energy use input appropriate energy demand values in optimization tools for the industrial sector