**Fate of Antioxidants in Gut and Interaction of Gut Metabolites and Gut Microbiota**

Editor

**Baojun Xu**

Basel • Beijing • Wuhan • Barcelona • Belgrade • Novi Sad • Cluj • Manchester

*Editor* Baojun Xu Beijing Normal University-Hong Kong Baptist University United International College Zhuhai, China

*Editorial Office* MDPI St. Alban-Anlage 66 4052 Basel, Switzerland

This is a reprint of articles from the Special Issue published online in the open access journal *Antioxidants* (ISSN 2076-3921) (available at: https://www.mdpi.com/journal/antioxidants/special issues/Antioxidants Gut).

For citation purposes, cite each article independently as indicated on the article page online and as indicated below:

Lastname, A.A.; Lastname, B.B. Article Title. *Journal Name* **Year**, *Volume Number*, Page Range.

**ISBN 978-3-0365-8532-1 (Hbk) ISBN 978-3-0365-8533-8 (PDF) doi.org/10.3390/books978-3-0365-8533-8**

© 2023 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license. The book as a whole is distributed by MDPI under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) license.

## **Contents**


Reprinted from: *Antioxidants* **2021**, *10*, 384, doi:10.3390/antiox10030384 .............. **227**


## **About the Editor**

### **Baojun Xu**

Dr. Baojun Xu is a Chair Professor in Beijing Normal University–Hong Kong Baptist University United International College (UIC, a full English-teaching college in China), Fellow of the Royal Society of Chemistry, Zhuhai Scholar Distinguished Professor, Department Head of the Department of Life Sciences, Program Director of Food Science and Technology Program, author of over 300 peer-reviewed papers. Dr. Xu received a Ph.D. in Food Science from Chungnam National University, South Korea. He conducted postdoctoral research work in North Dakota State University (NDSU), Purdue University, and Gerald P. Murphy Cancer Foundation in USA during 2005-2009. He did short-term visiting research in NDSU in 2012, and University Georgia in 2014, followed by visiting research during his sabbatical leave (7 months) in Pennsylvania State University in USA in 2016. Dr. Xu is serving as Associate Editor-in-Chief of *Food Science and Human Wellness*, Associate Editor of *Food Research International*, Associate Editor of *Food Frontiers*, and the editorial board member of around 10 international journals. He received the inaugural President's Award for Outstanding Research of UIC in 2016, President's Award for Outstanding Service of UIC in 2020. Dr. Xu has been listed in the world's top 2% scientists by Stanford University in 2020, 2021, 2022, and has been listed as one of the best scientists in the world in the field of Biology and Biochemistry at Research.com in 2023.

## **Preface**

The interactions between antioxidants and gut microbiota significantly impact the bioavailability of antioxidants by boosting the diversity of gut microbiota and the generation of bioactive metabolites by the microbiome. Thus, the potent health advantages of dietary antioxidants may be explained by their active, reciprocal interactions or cascades between commensal gut bacteria, food antioxidants, and the metabolites they generate. However, there is still a significant gap in our knowledge about the final fate of antioxidants in the gut, how antioxidant metabolites affect the gut microbiota, and how gut microbiota affects the metabolism of antioxidants. Thus, this Special Issue discusses the latest knowledge on the fate of antioxidants in the gut and the role antioxidant gut metabolites play in reducing oxidative stress in various gut and metabolic diseases. This Special Issue is a balanced collection of original scientific research papers and authoritative reviews on in vitro or in vivo studies relating to any of the following topics: the fate of antioxidants in gut; antioxidative activities of phytochemicals in the digestive system; molecular mechanisms of phytochemical antioxidants in maintaining gut health; and interactions of antioxidant metabolites and gut microbiota contributed by invited experts in the field as well as a careful selection of submissions based on a general call for papers.

This Special Issue includes seven research papers and four reviews on recent findings in the field. Tang et al. report that Bacillus amyloliquefaciens SC06 can induce AKT–FOXO signaling-pathway-mediated autophagy to reduce oxidative-stress-induced apoptosis and cell damage in IPEC-J2 Cells. Tan and co-workers observed that quercetin supplementation in male C57BL/6J mice fed with a high-fat diet significantly increased the population of Akkermansia and decreased the Firmicutes/Bacteroidetes ratio in feces. In another study, Kang et al. reported that the oral administration of selenium- and zinc-enriched *Lactobacillus plantarum* SeZi significantly enhanced the concentrations of selenium and zinc in blood samples of mice. The consumption of *Dendropanax morbifera* leaf (DML) extracts containing high concentrations of chlorogenic acid and rutin showed concentration-dependent liver protection in animal models. The oral administration of Polymethoxyflavone (PMF)-rich fraction from Ougan (*Citrus reticulata* cv. Suavissima) fruit enhanced the population of Lactobacillus and Bifidobacterium in the gut microbiota. In another study by Gu et al, lipids such as coconut oil, sunflower oil, and beef tallow were reported to promote the bioaccessibility of both anthocyanins and phenolic acids from black carrot during intestinal digestion. Time-trend differential pulse voltammetry kinetic data by Olivas-Aguirre et al. revealed concurrent epithelial permeability and biotransformation of bioactive compounds from small berries. In a review, Ballway et al. have efficiently described the mechanisms of gut dysbiosis, leaky gut, endotoxemia, and fatty liver disease with a specific focus on the alcohol-associated pathways. Makarewicz et al. reviewed the bidirectional relationship between polyphenols and the gut microbiome in detail. Koudoufio et al. documented that the interaction of dietary polyphenols and micro-ecology promotes multiple physiological functions in humans. In addition, Singh et al. discuss in detail the effects of polyphenols on inflammation in the brain–liver–gut axis.

Overall, this Special Issue provides up-to-date findings related to the fate of antioxidants in the gut, interactions of antioxidant metabolites and gut microbiota and molecular mechanisms of phytochemical antioxidants in maintaining gut health and managing various diseases. We would like to take this opportunity to thank Prof. Stanley Omaye, the Editor-in-Chief of *Antioxidants*, for giving us this great opportunity to publish this Special Issue "Fate of Antioxidants in Gut and Interaction of Gut Metabolites and Gut Microbiota". We also appreciate the contributions from subject matter experts and congratulate them for their significant findings and hard work. We also owe our peer reviewers a huge debt of gratitude for their insightful comments that helped to improve the quality of manuscripts published in this issue.

> **Baojun Xu** *Editor*

*Article*
