Introduction

I can't convey how exciting it's been to watch gut health gradually emerge into the mainstream. Over a decade ago when I was experiencing debilitating gut symptoms every day, digestion was kept very hush-hush. The science was just starting to emerge, and useful science-based resources were almost nonexistent. When I started writing about gut health and the microbiome, most people who knew me were perplexed. More than once I took an editor's call in a coffee shop and the people at the next table - overhearing me talk about digestion - discreetly moved to another location.

But somewhere along the line, gut health went big. Maybe it was the incredible advancements in gut microbiome science or the publication of popular books on the digestive system, such as Giulia Enders' Gut. Maybe it was the fact that fecal matter became established as a lifesaving cure for recurrent Clostridioides difficile infection. Now gut health is everywhere - in popular books, on social media, in blogs, in newspapers and online articles, and in documentary films - and now in this book, Gut Health For Dummies.

Whether you're here out of desperation to rid yourself of symptoms or you're a fan of GutTok or other gut health content on social media, you've come to the right place. This book gives a solid scientific grounding in everything related to the gut - and this exciting journey shines a light on some dark and twisty corners of your body, with lots of surprising facts along the way. If you become squeamish at any time during this journey, just put down the book, pour yourself a tall glass of water, and remind yourself that what goes in must come out in one way or another. Appreciate that the gut is an incredible, complex system that enables you to be who you are as a human.

Gut health is getting more exposure at just the right time - because more and more people are experiencing digestive health problems that affect their lives. According to the American Gastroenterological Association, up to 70 million people in the United States have a gastrointestinal disease that interferes with their quality of life. And digestive problems have gotten in the way of desired activities for 40 percent of people at some point. In Canada, the incidence of digestive disease is even higher than in the United States - more than 50 percent of people are affected by symptoms. Despite these high numbers, many people delay seeking medical advice for gut-related issues. I hope this book brings clarity about your gut health experiences so you feel confident seeking the care you need - and take proactive steps to avoid gut health problems for many years into the future.

About This Book

Gut Health For Dummies isn't like the other gut health books on bookshelves. Most books about gut health purport to have the one-and-only solution to fix your gut health, whether it's a six-step plan, a restrictive diet, or an expensive array of supplements. The problem with those approaches is that they don't have adequate scientific support: They may have worked well for some person at a particular time, but they're not shown to work reliably. And they're often short-sighted, treating diet as the only thing that matters for gut health. (Spoiler alert: This book identifies many different aspects of your lifestyle that converge to shape your gut health.)

I suffered through years of digestive symptoms without a diagnosis and eventually found relief by changing multiple aspects of my lifestyle, which I share throughout this book. Now, I'm passionate about understanding the science and knowing how to apply it in real life, so everything I report in these pages is based on genuine scientific findings and expert opinion, without hyping any individual findings. Because I make a living working with scientists in this field, I take great care to ensure that everything I say is appropriate and evidence-based according to what they'd expect.

Here I give you the knowledge to tell what claims and information are scientifically backed - so you can understand which products are likely to work versus which ones are relying on more of a wish and a prayer. When you're able to evaluate products with a critical eye, you're not at the mercy of whichever company has the biggest marketing budget. I aim to create the resource that I never had when I suffered from my own gut health issues and felt bombarded by all kinds of confusing and expensive products, all claiming to cure what ailed me. Now with the increased popularity of gut health, the market is even more saturated with products purporting to fix your gut. However, I understand that daily decisions are complex, so if you end up deciding, because of a friend's recommendation or a social media influencer, that you want to try consuming a product with no scientific proof that it works, that's your choice. I only hope you'll be able to navigate your way through the world of gut health with awareness and better confidence.

In true Dummies style, the information in this book is presented in a clear, concise format with practical tips throughout. I capture the latest scientific thinking and translate it into everyday actions that represent the best-known ways to take care of your gut throughout your life.

This book extensively covers the microbiome of your gut. Your digestive tract microbiome is really several different microbiomes in different locations. Yet the microbiome of the colon is by far the most frequently studied because of the ease of collecting samples. (I mean, everyone deposits samples of this microbiome regularly into the toilet.) So, the term "gut microbiome" in scientific papers most often refers to the colonic, or fecal, microbiome. Throughout this book, therefore, gut microbiome refers to the colonic microbiome unless otherwise specified.

Sources of information about gut health often use dysbiosis to refer to a disrupted or abnormal gut microbiome. Dysbiosis can look a million different ways, even for a single disease. It can't even be defined as an imbalance between good and bad bacteria in the microbial ecosystem because the concepts of "good" and "bad" simply don't apply to microorganisms. For these reasons, dysbiosis has fallen out of favor in the scientific community, and I avoid it as well in this book. I tend to use the general terms "difference" or "disturbance" when talking about gut microbiome alterations associated with poorer health, lest people think dysbiosis is something that can be specifically defined and diagnosed.

The recipes in this book are complete, but they may not spell out every detail of prepping and cooking the food. For example, certain steps and techniques in cooking are standard no matter what you're preparing. In addition, I require specific types of ingredients and also want to make sure that you adhere to a few of my other cooking preferences. Take a quick look at the following list for points that apply to all the recipes:

• Fruits and vegetables are washed under cold running water before using.
• Pepper is freshly ground pepper. Invest in a pepper mill and give it a few cranks when you want pepper bursting with flavor.
• Fresh herbs are specified in many of the recipes for their bright, authentic flavor. But you can still make a recipe if you don't plan to use these by substituting dry herbs, using one-third the amount of fresh.
• Dairy products are low-fat.
• Eggs are large unless otherwise indicated.
• Olive oil is extra-virgin unless otherwise indicated.
• All onions are sweet unless otherwise indicated.
• Water is filtered water.
• All temperatures are Fahrenheit.
• Keep pots uncovered unless I tell you to put on the lid.
• This tomato icon indicates that the recipe is vegetarian.

Foolish Assumptions

When writing this book, I make the following assumptions about you:

• You've heard about gut health but may not be familiar with the scientific jargon, so I define new terms as they're introduced.
• You're suffering from digestive symptoms and you're open to seeking medical help and taking advantage of the interventions that have the best scientific support.
• Even if you don't have regular digestive symptoms, you're also interested in leveraging the best science to maintain your gut health and overall wellness.

Icons Used in This Book

Throughout this book you'll see the following icons to draw your attention to certain paragraphs.

When you see this icon, it flags practical advice for putting gut health science into practice.

This icon highlights key points that help you gain a better understanding of gut health in general.

This icon indicates more detailed (nonessential) information for people who want to level up their knowledge.

This icon alerts you about what to watch out for if you want to avoid gut health problems.

This icon shows where a leading scientist weighs in specially for this book to bring you the latest knowledge in the field.

Beyond the Book

I hope you continue your gut health journey even after you read the last page of this book. For more information, you can check out the book's accompanying Cheat Sheet - go to www.dummies.com and search for...