The Diet Myth: Review & Summary: Is Your Gut the Key to Weight Loss?

The Diet Myth Review and Summary: Is Your Gut the Key to Weight Loss? 

"The Diet Myth is fascinating, and now I'm obsessed with microbes!' --- Nigella Lawson

We are all increasingly bewildered by the simple question of what to eat. Despite advice from experts, governments, and dieticians about the dangers of too much fat, sugar, protein, and lack of exercise, our nutrition - and the global obesity crisis - is getting worse.

Why can one person eat a certain meal and gain weight and another eat exactly the same food and lose pounds? Genes provide part of the answer, but we have been overlooking one vital aspect of diet that lies within us. 

Thanks to recent breakthroughs, scientists have begun to examine the permanent residents in our guts: the thousands of previously unknown but essential microbes whose job it is to digest our food and keep us alive.

Drawing on the latest science and his own research team's pioneering work, Professor Tim Spector explores the hidden world of the microbiome and demystifies the common misconceptions about fat, calories, vitamins, and nutrients. 

Only by understanding how our own microbes interact with our bodies can we overcome our confusion about modern diets and nutrition to regain the correct balance of our ancestors.

Mixing cutting-edge discoveries, illuminating science, and his own case studies, Spector shows why we should stop listening to the myths of diet fads and instead embrace diversity for a healthy gut and a healthy body.

Book: The Diet Myth: Why the Secret to Health and Weight Loss is Already in Your Gut by Tim Spector

Discover the truth behind weight loss and dieting with The Diet Myth by Tim Spector. Learn why exercising more and controlling your diet may not result in weight loss, and how your gut holds the key to optimal health and weight management. Tim Spector's groundbreaking research explained. A must-read for anyone seeking a sustainable approach to weight management.

About the Author: Tim Spector

Tim Spector is Professor of Genetic Epidemiology at King's College London and Hon Consultant Physician at Guy's and St Thomas' Hospital. He has won several academic awards and published over 700 academic papers, a large proportion of which relate directly to nutrition and the causes of obesity. 

He has appeared in numerous TV documents and is often consulted in British and international media on his team's research. Since 2011 he has been leading the largest microbiome project in the UK, using genetic sequencing to study the bacteria in the guts of 5, 000 twins. 

He is the lead investigator for BRITISH GUT, the UK's largest open-source science project to understand the microbial diversity of the human gut.

Related Topics: 

• The Best Books on Gut Health to Read 
• The Diet Myth Review: Is Your Gut the Key to Weight Loss?
• The Mind-Gut Connection by Emeran Mayer (summary & review)
• The 30 Best Books on Health and Fitness

Book Summary: The Diet Myth by Tim Spector

The efficacy of food comes from all the ingredients in natural food and thousands of metabolic by-products generated during the interaction between food, food, and microorganisms in the body. (So ​​most of the health care products on the market are useless)

The more varied your diet, the richer your gut flora, and the better your health. This applies to anyone of any age.

Main points:

1. Increase food diversity, which is conducive to the growth of intestinal flora. Learn the Mediterranean diet, increase whole grains, olive oil, various fresh fruits and vegetables, nuts, red wine, fish, and dairy products;
2. Eat more organic food and reduce the indirect intake of antibiotics and hormones. Antibiotics will greatly reduce intestinal microorganisms;
3. Be wary of the sugar in processed foods; sweeteners are also bad, they will disrupt the function of intestinal flora, negatively affect metabolism, and endanger health;
4. Dark chocolate containing 70% cocoa is good for health. People who eat chocolate often have healthier metabolism and intestinal flora;
5. Drinking a cup of coffee early in the morning can wake up the microorganisms in the body. Coffee contains polyphenols and cellulose, while tea has no cellulose;
6. Frequent and small drinking can greatly increase the variety of gut microbes;
7. As long as no salt is added, eating 30 grams of mixed nuts per day compared with the low-fat diet group has a significantly lower risk of heart disease, which is almost as effective as extra consumption of olive oil;
8. Proper fasting and learning to starve can reduce body fat and stress-related cortisol levels.

After reading this book, I finally understood the deep-seated reasons why my weight increased after a lot of exercise. 

In addition to the increase in food intake and muscle mass caused by high consumption, the biggest impact is actually the reduction in consumption at rest and the slowing down of metabolism. 

I have always smugly thought that I have strengthened my heart, and the resting heart rate has dropped from more than 70 before to 55 now, and the function has become stronger, but I did not realize that this also means that consumption has slowed down. Therefore, everything is too late, for self-examination.

Book Reviews of The Diet Myth by Tim Spector

Anti-nutrition nutrition

Others write books to tell readers that "a certain eating habit is good or bad for health". The author wrote the book to tell readers that it is often meaningless to discuss "whether a certain eating habit is good or bad for health".

I used to read a lot of scientific reports on the relationship between diet and health for a period of time due to work needs. 

I had a strong feeling that: Today there is a paper saying that "eating ×× is good for health and can reduce the risk of a certain disease by ×× "; Within a few days, another paper stated that eating the same thing "may increase the risk of suffering from XX disease by XX percent". 

Most of these papers are based on observational studies or experimental studies on a large number of samples and have excluded various interference factors. They seem to be very scientific and rigorous so you cannot question them.

The problem is, if you're like me, you've read too many conflicting studies and you're bound to wonder, who am I supposed to listen to? Are these studies really reliable?

As the authors of this book write: "No field in science or medicine is so rife with infighting, lack of consensus, and lack of rigorous experimental research to support the health claims of various dietary guidelines .”

The author wrote this book in response to this phenomenon. His starting point is not to tell you what kind of eating habits are the healthiest, but to clarify various "myths " in modern dietary concepts.

for example:

• Does Exercise Really Help You Lose Weight?
• How many meals a day is the most scientific?
• Do you have to have breakfast?
• Does milk make you taller and stronger?
• Is probiotic-fortified yogurt really beneficial?
• How about drinking vegetable soup instead of fruit juice?
• Are low-fat diets necessarily healthier?
• Moderate consumption of chocolate does more good than harm?
• Can drinking red wine prevent heart disease?

If I were introducing other books, I might say at this time: "You can find the answers to the above questions in this book." But if I want to introduce this book, I can only say sorry: "You can't find the exact answer to the above questions in this book."

This is what makes this book so special. What the author has to do is to "clarify myths and break rules and regulations" instead of proposing a new diet plan to replace the existing diet plan.

In the face of a specific dietary suggestion, or a self-contained dietary plan, we should not rush to accept or oppose it, but measure the principles behind it from a scientific perspective. 

In the book, the author often puts forward counterexamples of certain dietary advice and then proceeds from these counterexamples to clarify the truth. 

And the reason why he can "see the sun through the clouds" is due to these two sets of skills: genetics research and gut microbe research.

Genetics perspective

Take, for example, one of the most common "myths" -- what factors affect weight. The first thing that comes to mind is exercise and diet. In fact, countless scientific types of research are made around these two factors. 

However, the author took another approach and narrowed down the research object to twins.

His research found that identical twins were closer in weight and body fat than fraternal twins. Specifically, the average weight difference between identical twins was less than 1 kilogram. 

Considering that identical twins have the exact same DNA, the importance of genetic factors can be seen.

Here, I would like to insert a sentence. This kind of observational study on the weight of twins should exclude some influencing factors. 

For example, the weight of twins may be close to each other because they have lived together for a long time, and the similarity in eating and exercise habits is higher than random. Draw two strangers. 

Although the author did not mention these interference factors in the book, I believe his research must be in line with scientific norms.

The authors also point out that genes can even influence how you chew, your dietary preferences, and how often you exercise. According to the authors, genetic factors can explain 60% to 70% of the individual variation among different people.

Regarding whether exercise can lose weight, the author not only cites a large number of follow-up surveys to show that the weight loss effect of exercise is not obvious but also theoretically explains that the reason why most people fail to lose weight through exercise is that the changes in the body offset the effect of exercise. 

Specifically, The body's self-protection mechanisms prevent us from burning fat too much. Exercise may turn some fat into muscle, but the body weight will not change much. As for whether diet control can reduce weight, the author also made an analysis, so I won’t introduce it here.

Of course, the authors also pointed out that exercise is good for health because exercise can improve heart function and improve intestinal flora. So, it’s always a good idea to exercise!

Of course, genes don't determine everything. For example, the authors write: "Genetics do not account for the enormous changes that have occurred in the population over the past two generations. Obesity in the UK was 7% in 1980 and 24% today. 

Genes made of DNA molecules cannot With such a rapid change, generally speaking, under the action of natural selection, it will take at least a hundred generations for the variation to occur.” 

What’s more, as mentioned earlier, genetic factors can only explain 60% to 70% of individual differences at best. Clearly, additional tools are needed to study the relationship between diet and health.

Microbial Perspective

Where genetic factors cannot be explained, the author resorted to his trump card, which is also the research perspective repeatedly emphasized throughout the book Flora. 

The authors believe that the gut microbiome is key to dispelling many myths about modern diets. Prior to new discoveries in this field, nutrition and weight issues were narrowly understood as energy intake and expenditure, without taking into account the influence of the microbiome, which is why dietary plans and nutritional advice often fail.

That is to say, the same dietary plan and nutritional advice only apply to some people, but not to others. In addition to personal genetic differences, it is largely due to different people having different gut flora. 

There are thousands of species of major bacteria in the human body, and no two people have the same bacterial makeup. Studies have found that even identical twins have more than 50% of the same bacterial species, compared with about 40% for ordinary people.

It is through extensive application of gut flora research that the authors conclude: " There is no one diet that works for everyone, and each of us has a unique gut flora that responds to food. 

Different responses and these responses are not static. Our journey in life is a journey to find the best diet for us ."

Similarly, for a specific "myth", how the author uses intestinal flora to clarify and solve it, interested readers can read the book by themselves, there is no need to show it one by one here.

This article basically ends here. Below are two long appendices. Appendix 1 is the four common diet plans mentioned in the book. 

The author lists these dietary plans not to tell everyone whether to accept or oppose them, but to treat them as a kind of "myth", and the truth can only be known after clearing the fog. Appendix II is some general knowledge about dietary health and nutrition that I have extracted from the book. 

In the author's opinion, only by combining the characteristics of one's own intestinal flora and continuous debugging can one find a diet plan that suits one's own needs. And as readers, understanding these common senses is the beginning of any effort we make.

Appendix 1: Dizzying Diet Plans

The book focuses on the following four diet programs.

Mediterranean diet

There are many variants of the Mediterranean diet, the most representative of which is the traditional diet in olive-growing regions such as Greece and southern Italy in the late 1950s and early 1960s. 

This diet is characterized by high consumption of whole grains, legumes, other types of fruits and vegetables, and nuts; high intake of fat, mainly from monounsaturated fatty acids in olive oil; moderate to large amounts of fish; moderate Pork and dairy products (mainly yogurt or cheese); small amounts of red meat, processed meat, and other meat products; moderate alcohol consumption, usually red wine with meals.

Rates of heart disease and stroke have been consistently lower in Mediterranean countries than in northern Europe and the United States. Many scientists agree that this is largely an effect of diet rather than a fluke of genetics. There was a large study called PREDIMED in the early 2000s. 

According to the existing results, the study that was stopped midway can prove that the Mediterranean diet can reduce the incidence of heart disease and stroke, and can improve blood lipids, blood cholesterol levels, and blood pressure. 

On this basis, the author focuses on the analysis of the role of olive oil. Interested readers can read the detailed analysis in the book.

Atkins diet

The Atkins diet may lose weight faster in the short term than a low-fat diet, because it is less efficient to obtain energy for survival from protein and fat than to obtain energy from carbohydrates, that is, in order to obtain The same energy, the body consumes more energy.

Another reason is that fats and proteins tend to fill you up more than most carbohydrates, which is the effect of gut hormones on the brain. Also, like other diets, restricting the types of foods you eat apparently reduces your total caloric intake.

Well-designed controlled studies have shown that after 6 weeks of implementing any strict diet plan and losing more than 10% of body weight, the body's energy expenditure and metabolism will decrease to help the body maintain previous fat reserves. 

After a period of a high-protein diet, cortisol levels will increase and thyroxine levels will decrease, because both conditions can increase fat storage and reduce energy expenditure levels. 

The latest version of the Atkins diet emphasizes the importance of low carb rather than zero carbs, and it also ditches heavy meat consumption. They also tried to get people to increase their intake of plant fiber. 

Although the dietary restrictions were relaxed, side effects such as gout, constipation, and bad breath still existed.

Paleo diet

Paleo diets come in many variants, with varying degrees of tradition and rigor. The rationale behind this diet is that humans have been eating this way for millions of years and have fully adapted to it. 

On the other hand, the speed of human evolution cannot keep up with the speed of diet changes since entering farming civilization, which means that human beings cannot adapt to these new foods.

However, the author believes that the main shortcoming of this theory is that it does not take into account the findings of the latest genetics or evolution research, but treats people as immutable machines. 

It also ignores the gut microbiome, which is closely related to human beings, constantly adapting and evolving. Also, we don't know exactly what foods our ancestors ate.

Intermittent fasting

Fasting usually refers to a daily caloric intake of less than 30% of the daily requirement. One type of fast is the "long-term fast," which cannot be sustained without a will of steel. 

A compromise is to eat normally five days a week and reduce caloric intake to less than one-third of the daily requirement (500 and 600 kcal for women and men, respectively) for the remaining two days. 

Gut studies in the United States and the United Kingdom showed that the fasting group had the most significant improvement in the gut microbiota, with a greatly increased diversity. 

Short-term fasts will promote the growth of good bacteria, but only if the diet is varied on those days when the normal diet is eaten. 15,000 years ago, our ancestors ate about 150 foods a week; today most people eat fewer than 20.

Appendix 2: Instead of obsessing about diet, it is better to learn common sense

The following content is excerpted from "The Myth of Diet", Guangxi Normal University Press, 2019 edition, author Tim Spector, translator Li Chaoqun.

Energy Calculation Formula

The so-called energy calculation formula, that is, how much energy a certain food can produce, is problematic in itself, because it "does not consider the freshness of the food and the influence of different cooking methods, and the cooking method can determine the degree of absorption and the speed of blood sugar rise. 

In addition, people with longer large intestines absorb more calories from food than people with shorter large intestines, and some studies have shown that the length of the intestines can vary by as much as 50 centimeters."

Butyrate

Butyrate is a short-chain fatty acid that is beneficial to health and is produced when bacteria in the colon digest and decompose foods containing cellulose and carbohydrates, especially polyphenols. 

Butyrate has antioxidant and anti-inflammatory properties that activate the immune system. Scientists believe that exercise can promote the production of butyrate. 

The researchers also found that people with greater microbial diversity had lower levels of inflammation and higher concentrations of the beneficial butyrate.

Cheese and microbial diversity

The more artisanal the cheesemaking process, the less sterilization is done and the greater the variety of microorganisms in and on the cheese. Although many countries have misgivings about the way French artisanal cheese is produced, food poisoning incidents caused by artisanal cheese are not many. 

At the same time, some clinical trials have also confirmed that giving cheese products to patients taking antibiotics can speed up the recovery of patients and reduce drug resistance. 

This is because antibiotics destroy healthy gut flora as well as harmful bacteria, and if patients were given unpasteurized hard cheese along with antibiotics, the diversity of gut microbes could be restored as quickly as possible, while sterilized industrially produced cheese has no such effect.

Fats and lipids

Fat accounts for about 1/3 of the body weight, without fat, people cannot survive. As a nutritional term, fat refers to anything composed of fatty acids. The fatty acids that make up fat are called "lipids." Lipids are insoluble in water and blood. They are mainly synthesized in the liver and wrapped up in the liver. 

After being combined with proteins, they are transported to various parts of the body through the blood. Lipid molecules come in a variety of shapes and sizes serve as the building blocks of cells and provide energy for vital organs. 

Lipids composed of short-chain fatty acids are usually liquid (such as oils), and lipids composed of long-chain fatty acids are usually solid at room temperature (such as fats). People cannot live without fat, and if there is a lack of fat in the diet, the liver will convert it at any cost.

HDL and LDL

Lipids combine with proteins to form lipoproteins. Lipoproteins in the blood are divided into high-density lipoprotein (HDL) and low-density lipoprotein (LDL). Their job is to carry cholesterol. 

LDL is the "bad" lipoprotein that deposits lipid molecules on the walls of blood vessels, forming plaques that can lead to a heart attack or stroke. 

If the liver produces a large amount of "good" lipoproteins such as high-density lipoproteins, most of the lipids can be safely transported to the parts where they are needed to be broken down and absorbed without causing any harm.

Cholesterol

Cholesterol is an essential lipid synthesized by the body to maintain the integrity of cells. Apolipoproteins bind to it and transport it to various parts of the body. High blood cholesterol levels are linked to heart disease risk, but the risk is overstated. Cholesterol is found in many foods, including fish and nuts.

Saturated Fat vs. Unsaturated Fat

Saturated fat is a type of fat that doesn't have hydrogen bonds and is found in abundance in oils such as coconut and palm oil, dairy products, and meat. It used to be considered harmful to health. 

Vegetable oils such as canola, olive, argan, and avocado are high in unsaturated fatty acids. The red meat and white meat we often talk about actually contain both saturated fat and unsaturated fat. 

The red color of red meat is due to the presence of myoglobin in special muscle fibers that increase muscle endurance, while white meat like chicken lacks myoglobin. In the words of the authors, "This is why chickens can run across the road but not run marathons. reason". 

Chicken has less total fat, a lower proportion of saturated fat, and 2/3 is unsaturated fat. Saturated fat and unsaturated fat in beef, pork, and mutton account for about half each. The fat content of different parts of meat also varies greatly.

Olive oil

Studies have shown that olive oil may reduce the risk of heart disease and diabetes and has anti-inflammatory properties. Until recently, the benefits of polyphenols in olive oil were thought to be primarily antioxidant - removing harmful substances from cells and having anti-inflammatory properties. 

Other studies have shown that olive oil can silence most of the genes that trigger the inflammatory response in blood vessels that leads to heart disease (likely through epigenetics). 

However, studies have shown that olive oil has a greater impact on the body's microbiome. More than 80% of the fatty acids and nutrients in olive oil reach the colon before being fully absorbed, where they come into direct contact with gut microbes. 

The author believes that olive oil can be seen as the spokesperson of the new dietary order, which breaks the view that "any food containing saturated fat is unhealthy".

Omega-3 and Omega-6

Omega-3 (omega-3) is a polyunsaturated fatty acid. It is an essential fatty acid that can be obtained in the diet, mainly from wild deep-sea fish and some plants, such as flaxseed. 

Omega-3s reduce lipids, reduce inflammation, and may also benefit heart health. It is said to be effective against many diseases, such as dementia, attention deficit, and arthritis. 

Omega-6 (omega-6) is also a polyunsaturated fatty acid essential to the human body, which is widely found in vegetable oils. Omega-6 is also found in fatty meat and farmed fish-fed soy and corn feeds. 

Many studies have suggested that a diet low in omega-3 to omega-6 ratios may be bad for health, but the authors cite other studies as controversial. The author also reminded me that after testing, the Omega-3 content of many fish oil health products did not reach the concentration advertised.

Trans fat

Margarine obtained from processing plants is conveniently packaged, has a long shelf life, and is inexpensive. It has been favored by the food industry and is widely used in a variety of processed foods and dairy substitutes. 

But for plant molecules to combine and form a solid state, a chemical process called "hydrogenation" is required, which produces large amounts of trans fats. One of the reasons trans fats are a health hazard is their effect on small fatty acids that act as signaling molecules from natural and artificial fats. 

Small molecular fatty acids are key molecules for information transmission in the body's immune system, intestinal microbes, and fat metabolism. 

Artificially hydrogenated vegetable oils disrupt this process, affecting signaling and thus metabolism. 

Facts have shown that even a small daily intake of trans fats can significantly increase blood lipid levels, greatly increase the risk of heart disease and sudden death, and may also increase the risk of cancer. An estimated 250,000 Americans die each year due to trans fat consumption.

Junk food

Everyone knows junk food is bad for your health—saturated fat, high in calories, sugar, chemical additives, and lack of fiber. Long-term studies have consistently shown that people who regularly eat junk food, such as potato chips, French fries, and processed meat, gain more weight than other foods. 

Why is there such a thing as junk food? When people first started developing processed foods, researchers were busy with how to sanitize them and extend the shelf life of cakes, cookies, and snacks. 

They found that adding large amounts of sugar inhibited bacterial growth, and increasing the fat content reduced moisture, which reduced bacterial and fungal growth. 

Finally, besides fat and sugar, there is one wonder substance that extends shelf life and that is salt. Foods with a large amount of these three substances added can last for a long time. Burgers, pizza, cakes, and potato chips (french fries) are all three ingredients in significant amounts.

Sterilized milk

Milk contains a lot of microorganisms. Because of fear of infection, people no longer drink raw milk and replace it with sterilized milk. The process began in the early 20th century to prevent infections from diseases such as brucellosis, listeriosis, and tuberculosis, which can be transmitted through milk. 

At the same time, the process also reduces some rare but acute food poisoning infections, such as E. coli infections. To kill pathogenic bacteria, milk is rapidly heated to 72 degrees Celsius for 15 seconds, then rapidly cooled and bottled. 

Many people think that pasteurized milk is completely sterile, but new genetic testing methods show that bacteria still live in it. The heating process kills heat-sensitive bacteria, but many of the bacteria in milk are heat-resistant. 

Even those heat-sensitive bacteria that could cause illness are not all killed, just reduced in number.

Nutrient deficiencies due to a vegan diet

Many vegans and partial vegetarians suffer from nutritional deficiencies because vegetables contain little of some essential nutrients found in meat, such as vitamin B12, zinc, and iron. Vitamin B12 deficiency is common among vegetarians, which may negate some of the health benefits of a vegetarian diet.

Sugar, sucrose, glucose, and fructose

What we usually refer to as "sugar" is actually a mixture of two carbohydrates, glucose and fructose, also known as sucrose. Glucose is a natural source of energy: it travels throughout the body through the bloodstream, where it is used by cells to release energy and sustain life. 

Fructose is the source of sweetness and is a natural constituent of all fruits. In nature, only fruits contain fructose, but modern food processing makes fructose ubiquitous. All the while, the concern was the dangers of fat, while the use of sugar spread, cleverly marketed as a source of energy. In the food processing industry, the void left by fat is gradually being filled by sugar.

Caries and Plaque

Bacteria in general aren't used to large amounts of sugar, but one particular species - Streptococcus Mutans - loves sugar, feeding on the sugar around teeth and gums and multiplying rapidly. 

Unfortunately, unlike other non-pathogenic bacteria, it digests the sugar and produces lactic acid, which erodes tooth enamel and forms small cavities. 

Dental plaque as we know it is a sticky biofilm formed by groups of 600 non-pathogenic bacteria that adhere to each other. They break down the sugars, creating a jelly that keeps them firmly attached to the teeth while getting nutrients.

Monosaccharides, polysaccharides, carbohydrates

Small molecular sugars consisting of one or two molecules are called "monosaccharides" and "disaccharides", which are commonly known as sugars and are widely used in processed foods. 

Sugars with large molecules are called "polysaccharides", which have the function of storing energy or maintaining the skeleton of plants, such as cellulose. Most edible carbohydrates are called "starches," which are the main energy store of plants and the main ingredient of potatoes, bread, and rice. 

Starches are formed by long chains of glucose molecules tightly linked together. Some starches are easily broken down, while others are more stable in structure. 

The human body has only 30 enzymes that break down carbohydrates, but fortunately, intestinal bacteria have more than 6,000 enzymes, which can help the body digest these substances very well. Without the help of gut bacteria, eating starchy foods may simply be chewed, and not absorbed.

Dietary fiber

"Dietary fiber" is a general term for all foods that cannot be digested. In the past, people thought that it was completely inactive, had no other effect except to promote intestinal peristalsis, and would not react with the body. 

But in fact, the type of cellulose can vary from soluble fiber like oats, beans, and fruits, to insoluble fiber found in whole grains, nuts, seeds, bran, fruit pulp, and many beans and vegetables like green beans. 

However, even if insoluble fiber is not completely inactive, it can be broken down by bacterial fermentation, producing gas and other by-products. In general, cellulose absorbs water and speeds up bowel emptying. 

Although most people agree that cellulose is beneficial to There are health benefits, there is little consensus on why, possibly because cellulose has prebiotic-like effects.

Prebiotics

Prebiotics are one of the main ways in which food interacts with gut microbes and are ingredients in foods that promote the growth of beneficial bacteria in the colon. 

These are some macromolecular cellulose, and there are many kinds. Throughout our lives, the first exposure to prebiotics is the oligosaccharides contained in breast milk, which are complex compounds formed by tightly linked sugar molecules. 

Many prebiotics are called resistant starches to distinguish them from refined (broken down) starches such as rice and pasta that are easily digested and release glucose. 

Well-known prebiotics include inulin, fructooligosaccharides, and galactooligosaccharides. Prebiotics are found naturally in plants such as chicory root, Jerusalem artichoke, dandelion greens, leeks, onions, garlic, asparagus, wheat bran, flour, broccoli, bananas, and some nuts.