Probiotics and Prebiotics

Probiotics and Prebiotics Current Research and Future Trends

Edited by

Koen Venema and Ana Paula do Carmo

Caister Academic Press

Probiotics and Prebiotics Current Research and Future Trends

Edited by Koen Venema Beneficial Microbes Consultancy Wageningen The Netherlands

and Ana Paula do Carmo Instituto Federal do Espírito Santo - IFES Soteco Vila Velha Brazil

Caister Academic Press

Copyright © 2015 Caister Academic Press Norfolk, UK www.caister.com British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library ISBN: 978-1-910190-09-8 (hardback) ISBN: 978-1-910190-10-4 (ebook) Description or mention of instrumentation, software, or other products in this book does not imply endorsement by the author or publisher. The author and publisher do not assume responsibility for the validity of any products or procedures mentioned or described in this book or for the consequences of their use. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the publisher. No claim to original U.S. Government works. Cover design adapted from Figure 7.6. Ebooks Ebooks supplied to individuals are single-user only and must not be reproduced, copied, stored in a retrieval system, or distributed by any means, electronic, mechanical, photocopying, email, internet or otherwise. Ebooks supplied to academic libraries, corporations, government organizations, public libraries, and school libraries are subject to the terms and conditions specified by the supplier.

Contents

Contributorsvii Prefacexv Part I General Introduction  1

Probiotics and Prebiotics: Current Status and Future Trends

2

Functional Aspects of Prebiotics and the Impact on Human Health

Koen Venema and Ana Paula do Carmo Vicky De Preter and Kristin Verbeke

1 3 13

Part II Probiotics27 3

Lactobacilli as Probiotics: Discovering New Functional Aspects and Target Sites

29

4

Bifidobacteria – Regulators of Intestinal Homeostasis

43

5

Propionibacteria also have Probiotic Potential

69

6

Non-LAB Probiotics: Spore Formers

93

7

Mechanisms of Action of Probiotic Yeasts

105

8

Yeasts as Probiotics – Established in Animals, but what about Man?

115

9

Escherichia coli – More than a Pathogen?

135

10

The Paradoxical Role of Enterococcus Species in Foods

153

11

Use of rec LABs: Good Bugs to Deliver Molecules of Health Interest: From Mouse to Man

167

Koen Venema and Marjolein Meijerink

Thomas D. Leser, Caroline T. Gottlieb and Eric Johansen Gabriela Zárate and Adriana Perez Chaia

Loredana Baccigalupi, Ezio Ricca and Emilia Ghelardi Flaviano dos Santos Martins and Jacques Robert Nicoli Gunnard K. Jacobson Maïwenn Olier

Luís Augusto Nero, Svetoslav Dimitrov Todorov and Luana Martins Perin Jean-Marc Chatel, Natalia Breyner, Débora L.R. Gomes, Vasco Azevedo, Anderson Myioshi and Philippe Langella

iv  | Contents

12

The Indigenous Microbiota and its Potential to Exhibit Probiotic Properties

181

13

Improving the Digestive Tract Robustness of Probiotic Lactobacilli

195

14

Biology of Reactive Oxygen Species, Oxidative Stress, and Antioxidants in Lactic Acid Bacteria

205

Sylvie Miquel, Rebeca Martin, Muriel Thomas, Luis G. Bermudez-Humaran and Philippe Langella Hermien van Bokhorst-van de Veen, Peter A. Bron and Michiel Kleerebezem

Marta C.T. Leite, Bryan Troxell, Jose M. Bruno-Bárcena and Hosni M. Hassan

Part III Prebiotics

219

15

Functional Aspects of the Endogenous Microbiota that Benefit the Host

221

16

Studying the Microbiota and Microbial Ecology of the GI Tract in the Omics Era: Tools for Stools

235

17

Metagenomics of the Gut Microbiota as a Tool for Discovery of New Probiotics and Prebiotics

245

18

Emerging Applications of Established Prebiotics: Promises Galore 

265

19

Prebiotics: Technological Aspects and Human Health

275

20

New and Tailored Prebiotics – Established Applications 

289

21

Immunomodulating Effects of Prebiotics and Fibres

315

22

Prebiotics Beyond Fibres

331

23

Synbiotics – More than just the Sum of Pro- and Prebiotics? 

345

Koen Venema

Kieran M. Tuohy, Francesca Fava and Nicola Segata Hyun Ju You, Jiyeon Si and GwangPyo Ko Seema Patel

Vanessa Rios de Souza, Camila Carvalho Menezes, Luciana Rodrigues Cunha, Patricia Aparecida Pimenta Pereira and Uelinton M. Pinto Shanthi G. Parkar, Paul A. Blatchford, Caroline C. Kim, Douglas I. Rosendale and Juliet Ansell Hanne Frøkiær, Stine B. Metzdorff and Koen Venema Delphine M. Saulnier and Michael Blaut Koen Venema

Part IV Clinical and Medical Aspects of Pro- and Prebiotics

361

24

Pro- and Prebiotics: the Role of Gut Microbiota in Obesity 

363

25

The Role of the Gut Microbiota in Brain Function

381

26

Infant Development, Currently the Main Applications of Probiotics and Prebiotics?

391

27

Pro- and Prebiotics in Management of Patients with Irritable Bowel Syndrome

407

28

Pro- and Prebiotics for Oral Health

417

29

Cholesterol-lowering Effects of Probiotics and Prebiotics

429

Marc R. Bomhof and Raylene A. Reimer

Julia König, John-Peter Ganda Mall, Ignacio Rangel, Hanna Edebol and Robert-Jan Brummer Giuseppe Mazzola, Irene Aloisio and Diana Di Gioia

Ratnakar Shukla, Ujjala Ghoshal and Uday C. Ghoshal

Svante Twetman, Mette Rose Jørgensen and Mette Kirstine Keller Min-Tze Liong, Byong-H. Lee, Sy-Bing Choi, Lee-Ching Lew, Amy-Sie-Yik Lau and Eric Banan-Mwine Daliri

Contents |  v

30

Perspectives on Differences Between Human and Livestock Animal Research in Probiotics and Prebiotics

447

31

The Use of Probiotics to Enhance Animal Performance

459

32

Pharmaceutical Aspects of Probiotics and Prebiotics

469

Tyler E. Askelson and Tri Duong

Juliana Teixeira de Magalhães, Luciene Lignani Bitencourt, Marta Cristina Teixeira Leite, Ana Paula do Carmo and Célia Alencar de Moraes Indu Pal Kaur, Parneet Kaur Deol, Simarjot Kaur Sandhu and Praveen Rishi

Part V Future Perspectives

487

33

Future Possibilities for Pro- and Prebiotics: Is the Sky the Limit?

489

Appendix I: Web Resources

495

Index

505

Koen Venema and Ana Paula do Carmo

Cholesterol-lowering Effects of Probiotics and Prebiotics Min-Tze Liong, Byong-H. Lee, Sy-Bing Choi, Lee-Ching Lew, Amy-Sie-Yik Lau and Eric Banan-Mwine Daliri

Abstract Recently, the use of probiotics and prebiotics as a cholesterol lowering agent has become increasingly popular. This chapter will highlight some of the in vitro and in vivo evidence showing the potential of probiotics and prebiotics in improving serum lipid profile. Data revealing details at molecular levels have also been included in this chapter. The proposed mechanisms for cholesterol removal by probiotics include assimilation of cholesterol by growing cells, binding of cholesterol to cellular surface and incorporation into the cellular membrane, deconjugation of bile via bile salt hydrolase, coprecipitation of cholesterol with deconjugated bile and production of shortchain fatty acids from oligosaccharides. In this chapter, we have highlighted on a few more selected cholesterol lowering mechanisms that are feasible and supported by in-depth evidence. Although cholesterol lowering abilities of probiotics has been extensively reported; recently, controversies have risen attributed to the activities of deconjugated bile acids that repress the synthesis of bile acids from cholesterol. Using a molecular docking approach, we have demonstrated that deconjugated bile acids have higher binding affinity towards some orphan nuclear receptors namely the farsenoid X receptor (FXR), leading to a suppressed transcription of the enzyme cholesterol 7-alpha-hydroxylase (7AH), which is responsible for bile acid synthesis from cholesterol. Possible detrimental effects due to increased deconjugation of bile salts such as malabsorption of lipids, colon carcinogenesis, gallstones formation and altered gut microbial populations, which contribute to other varying gut diseases, are also included in this chapter. The effects of probiotics and prebiotics on other cholesterol-related disorders such as formation of abnormal erythrocytes are also discussed in this chapter. As described in the past studies, hypercholesterolaemia could induce alterations in the human erythrocyte plasma membrane. Administration of probiotics and prebiotics has improved erythrocyte membrane fluidity, decreased membrane rigidity and altered membrane lipid profiles. Probiotics and prebiotics is a new feasible approach to use natural interventions for cholesterol management.

29

Introduction Cholesterol is one of the essential structural components crucial in establishing proper cellular membrane permeability and fluidity in our body. Two of the main lipoproteins that transport cholesterol are the low-density lipoprotein- (LDL) and high-density lipoprotein (HDL)-cholesterol. During hypercholesterolaemia, higher concentrations of LDL and lower concentrations of HDL is usually found in blood and the excess can accumulate on the walls of the arteries, and together with plaques, this leads to the narrowing of the arteries. There are many risks associated with hypercholesterolaemia, ranging from coronary artery disease to heart attack and stroke, causing morbidity and mortality. With the increasing development of various drugs to ameliorate this metabolic disease, pharmaceutical companies have pumped huge investments in the discovery of potent drugs. Amid these, natural approaches such as non-drug strategies have also increased. Dietary intervention such as monitoring the intake of saturated fat and replacing saturated fat with mono or polysaturated fatty acids have always been highlighted by healthcare practitioners to their patients. Recently, the use of probiotics as a cholesterol lowering agent has also become increasingly popular. Hypercholesterolaemia is a metabolic derangement characterized by the presence of high levels of cholesterol in the blood (Ooi et al., 2010a). Elevated blood cholesterol is known to be a major risk factor for coronary heart diseases (Kumar et al., 2012a). It was predicted by World Health Organization (WHO, 2013) that cardiovascular diseases will remain as the leading cause of death by 2030, such that an estimation of 23.6 million people will die from the disease in the year 2030. Over 80% of cardiovascular disease-related deaths take place in low- and middle-income countries (WHO, 2013). According to a report, hypercholesterolaemia contributes to 45% of heart attacks in Western Europe and 35% of heart attacks in Central and Eastern Europe (Kumar et al., 2012a). Those with hypercholesterolaemia have three times higher risk of heart attack compared with those with normal blood lipid profiles (Kumar et al., 2012a). High blood cholesterol levels can be reduced by dietary management, behaviour modification, regular exercise or even drug therapy (Kumar et al., 2012a; Ooi et

430  | Liong et al.

al., 2010a). However, apart from the high cost of cholesterol lowering drugs, they may also present severe adverse effects (Kumar et al., 2012a). Probiotics and prebiotics, which could be a cheaper and safer alternative, have been studied to ascertain their ability to lower cholesterol. The beneficial effects of probiotics have been extensively studied for the last few decades and many strains of probiotics microorganisms have been evaluated for their cholesterol lowering properties. However, those from the genera of Lactobacillus, Bifidobacterium, Lactococcus, and Streptococcus have dominated most research publications in such a health benefit. Scientific evidence on the cholesterol lowering effects initially surfaced in 1959, where Danielsson and Gustafsson observed that the cholesterol level in germ-free animals were lower than in normal conventional animals (Danielsson and Gustafsson, 1959). Later, Beher et al. (1964) and Wostmann et al. (1966) reported that the intestinal microbiota was responsible for the conversion of cholesterol to coprostanol and conversion of primary bile to secondary bile; leading to a decrease in serum cholesterol levels. Mott et al. (1973) conducted an animal trial using cholesterolfed piglets and further confirmed that serum cholesterol was lowered by intestinal bacteria. Meanwhile, Mann et al. (1974) observed that when African Masaai men consumed large amounts of Lactobacillus strain fermented milk for 21 days, serum cholesterol level decreased compared with their initial levels. In addition, Harrison et al. (1975) reported that serum cholesterol level decreased when the Lactobacillus count in the bowel microbiota of newborn was increased. Since then, there have been numerous studies conducted to evaluate the cholesterol lowering properties of probiotics. Prebiotics, defined as ‘indigestible fermented food substrates that selectively stimulate the growth, composition and activity of microbiota in gastrointestinal tract and thus improve hosts, health and well-being’ (Roberfroid, 2007) has also acquired scientific recognition in cholesterol lowering effects in recent years. Prebiotics such as fructooligosaccharides (or oligofructose), inulin, lactulose, and galactooligosaccharides are fermented by gastrointestinal microbiota to further selectively stimulate the growth and/or activity of beneficial intestinal bacteria. In addition,

prebiotics are also utilized by the intestinal microbial population to produce short-chain fatty acids which may lead to improvement of lipid profiles. More recent studies do not only focus on the effects of probiotics and prebiotics on the serum total cholesterol levels, but also on the different types of lipoproteins and the triglycerides levels. In animal trials, the effects on the liver cholesterol and triglycerides content are also normally included. Expressions of genes responsible for cholesterol metabolism, catabolism and efflux have also been extensively studied in animals. This chapter will highlight some of these aspects. In vitro and in vivo evidence In vitro findings The potential cholesterol-lowering effects of probiotic strains are usually screened using in vitro methods. Previous studies have reported that lactobacilli removed cholesterol in vitro by various mechanisms. In a study evaluating the ability of lactobacilli to remove cholesterol in vitro under the conditions that mimic the human gastrointestinal tract, Lye et al. (2010a) observed that strains of lactobacilli were able to remove cholesterol via assimilation of cholesterol during growth, binding of cholesterol to the surface of cells (Fig. 29.1), disruption of cholesterol micelle and deconjugation of bile salts. The authors also reported that the removal of cholesterol was strain dependent and bile dependent. This was further corroborated by Pan et al. (2011) which reported that Lactobacillus fermentum SM-7 cells assimilated 61.5% and co-precipitated and absorbed 38.5% of the cholesterol in media containing 0.1 g/l cholesterol. Some bacteria including Lactobacillus species have been reported to have protease-sensitive receptors on the cell surface which may be responsible for tight contact with exogenous cholesterol/phosphatidylcholine vesicles. They then assimilate cholesterol into their own cell membrane to reduce membrane fluidity thereby influencing their membrane permeability (Efrati et al., 1981; Kumar et al., 2012a; Tani et al., 1993). Other studies have shown that probiotics may produce exopolysaccharides which may bind cholesterol, or that

Figure 29.1  Scanning electron micrograph images of lactobacilli cells growing in the absence of cholesterol (left) and cells grown in the presence of cholesterol (right). In the latter case, a rough surface was observed, illustrating the attachment of cholesterol onto cellular surface. Magnification: 10k x.

Cholesterol Lowering by Probiotics and Prebiotics |  431

the numerous amino acids and peptidoglycan in probiotic cell walls may account for the strong interactive forces with which both live and dead probiotics cells mop up cholesterol (Guo et al., 2011; Kimoto-Nira et al., 2007; Raghavan et al., 2011). In another in vitro study by Bordoni et al. (2013), it was reported that strains of bifidobacteria could also remove cholesterol by assimilating cholesterol during growth. It has also been reported that lactobacilli could reduce cholesterol in vitro via conversion of cholesterol to coprostanol and via incorporation of cholesterol into the cellular membrane during growth (Lye et al., 2010b). Moreover, Ahire et al. (2012) reported that growing cells of L. helveticus CD6 possessed high intracellular cholesterol oxidase-like activity, thus leading to degradation of cholesterol in vitro. In addition to cholesterol removal ability from cholesterol containing media, there have been increasing studies reporting on the ability of probiotics to interfere with intestinal cholesterol absorption. Niemann–Pick C1-like 1 protein (NPC1L1), a polytopic intestinal transmembrane protein containing a sterol-sensing domain, is essential in mediating cellular uptake of various sterols especially cholesterol (Yu, 2008). Huang and Zheng (2010) reported that probiotic L. acidophilus ATCC 4356 was able to reduce the expression of the NPC1L1 gene, leading to inhibition of cellular uptake of micellar cholesterol in intestinal Caco-2 cells. Similarly, it was reported that L. plantarum Lp27 isolated from Tibetan kefir grains inhibited cholesterol absorption through down-regulation of NPC1L1 expression in Caco-2 cells (Huang et al., 2013b). Similar trends were also observed by Yoon and co-workers where L. rhamnosus BFE5264 isolated from Maasai fermented milk and L. plantarum NR74 isolated from Korean kimchi down-regulated the expression of NPC1L1 in Caco-2 cells (Yoon et al., 2013). Another important protein that regulates cholesterol movement across cells is the heterodimeric transporter complex, ABCG5/ABCG8, the function of which is necessary for the majority of sterols secreted into bile (Kosters et al., 2006). It has been reported that treatment of Caco-2 cells with L. rhamnosus BFE5264 and L. plantarum NR74 also resulted in up-regulation and elevated expression of ABCG5 and ABCG8, thus promoting cholesterol efflux in enterocytes, leading to increased secretion of cholesterol into bile (Yoon et al., 2011). Most prebiotics promote the growth of lactic acid-producing bacteria. Through this they have also been proposed to have beneficial effects on lipid metabolism. In addition, intestinal fermentation of prebiotics leads to the production of substantial amounts of short-chain-fatty-acids (SCFAs) such as acetate and propionate, which can be transported to the liver via the portal vein and enters the cholesterogenesis and lipogenesis pathways. It has been suggested that the SCFAs produced by the intestinal microbiota may regulate lipid metabolism in intestine, thus reducing plasma cholesterol levels. Alvaro et al. (2008) showed that incubation of SCFAs namely acetate, propionate and butyrate to human Caco-2 enterocytes down-regulated the expression of nine key genes involved in intestinal cholesterol biosynthesis according to cDNA microarray analysis and quantitative realtime PCR. Besides exerting effects via SCFAs, prebiotics with long chain non-digestible polysaccharides such as β-glucan have

also been shown to down-regulate the intestinal cell expression of genes known to play critical roles in fatty acid and cholesterol synthesis and fatty acid transport (Drozdowski et al., 2010). In vivo findings The use of animal models and humans to evaluate the effects of probiotics on serum cholesterol levels has been emphasized over the years. However, recent studies have also focused on the lipoprotein profile as well as triglycerides level and liver lipid profiles. New strains of probiotics have been evaluated in animal models for their potential in cholesterol lowering effects (Table 29.1), while human studies have shown promising evidence that well-established probiotics possess significant cholesterol reducing effects (Table 29.2). Many studies have used rats, mice, hamsters, guinea pigs and pigs as models due to their similarities with humans in terms of cholesterol and bile acid metabolism, plasma lipoprotein distribution, and regulation of hepatic cholesterol enzymes (Ooi and Liong, 2010). These animals also share an almost similar digestive anatomy and physiology, nutrient requirements, bioavailability and absorption, and metabolic processes with humans, making them useful experimental models for research applications (Patterson et al., 2008). Hence, the positive cholesterol reducing effects shown in animal studies suggest a similar potential in humans. Human trial results that paralleled those obtained from animal studies have further attested to the transferability and reliability of results obtained in selected animal models. Many studies have evaluated the effects of probiotics on serum lipid profiles, intestinal lipid uptake and even liver lipid deposition. A recent study has illustrated that the administration of L. fermentum ATCC 11976 to hamsters on a high-cholesterol diet, yielded lower fat deposition compared with the control that were not administered with lactobacilli (Fig. 29.2). However, there are increasing data revealing details at molecular levels by investigating on the gene expression profile of the host tissue when probiotic strains were administered. Zhong et al. (2012) reported that administration of L. casei Zhang to male Wistar rats (n = 10) for 67 days evokes a significant reduction of serum triglyceride (TG) and low density lipoprotein-cholesterol (LDL-C) by 31.3 and 30.8% (P