How Significant and Powerful is the plant-based diet for gut health?

Vegetarianism is increasingly becoming popular as more people are choosing to switch to plant-based foods and diets. This could be due to a number of reasons, including health, religious reasons, environmental concerns, and animal welfare.

A well-balanced vegetarian diet includes a wide range of nutrient-dense foods, such as fruits, vegetables, whole grains, legumes, nuts, and seeds. It can provide various health benefits as it tends to be lower in saturated fats and higher in dietary fiber, potassium, folic acid, magnesium, vitamins C and E, and phytochemicals, such as flavonoids and carotenoids.

Following a vegetarian diet is associated with a wide range of human health benefits. This article looks into the benefits of a vegetarian diet and how you can maintain a balanced diet as a vegetarian.

What is a vegetarian diet?

Vegetarian is an umbrella term that includes a variety of diets:

• Lacto-ovo-vegetarians: vegetarians who eat dairy and eggs.
• Lacto-vegetarians: vegetarians who consume dairy products but not eggs.
• Ovo-vegetarians: vegetarians who consume eggs but not dairy.

People who avoid meat but consume fish in an otherwise lacto-ovo-vegetarian diet are known as pescatarians, while people who mainly consume a vegetarian diet but occasionally consume small amounts of meat are known as flexitarians. Although pescatarians and flexitarians are sometimes considered vegetarians, but since they eat animal flesh, they are not technically vegetarians.

Vegetarianism can sometimes be confused with veganism. Both vegetarians and vegans refrain from animal products for similar reasons. But the difference lies in the extent to which they find animal products acceptable. Vegetarians avoid all animal flesh and animal-derived products, such as meat, fish, poultry, dairy, etc. On the other hand, a vegan can be thought of as a stricter vegetarian who also refrains from eggs, dairy, and other animal-derived products.

Benefits of a Vegetarian Diet

1. Prevents type 2 diabetes
   Following a vegetarian diet can help prevent type 2 diabetes and the complications associated with it. This is because a vegetarian diet emphasizes on foods with a low glycemic index, such as whole grains, green leafy vegetables, nuts, and legumes, which help to stabilize your blood sugar levels.
   
   
2. Lowers blood pressure
   Researchers believe that people who eat a vegetarian diet tend to have lower blood pressure than meat eaters. This could be attributed to the fact that a plant-based diet is typically high in potassium and low in sodium, fat, and cholesterol, all of which help regulate your blood pressure.
   
   
3. Improves bone health
   People who follow a vegetarian diet have a lower osteoporosis rate than omnivores or meat eaters. This is because consuming proteins from animal foods leads to calcium loss and contributes to lower bone density. In one study it was found that people who ate a vegetarian diet for 20 years or more had a bone mineral loss of only 18 percent at 80 years of age, while the bone mineral loss for omnivores or meat eaters was 35 percent at the same age ^[1].
   
   
4. Reduces the risk of cancer
   While the difference is not significant, vegetarians are at a lower risk of cancer (especially colon cancer) than people who eat meat. Meat eaters tend to consume processed, smoked, or red meat and meats cooked at high temperatures that are known to increase the risk of certain types of cancers.
   
   A study conducted on low-risk populations found that a vegetarian diet could reduce the risk of cancer in general. In addition, the study showed that a vegan diet was most effective at cancer prevention and a lacto-ovo-vegetarian diet could reduce the risk of cancers of the gastrointestinal (GI) tract ^[2]. 
   
   Many experts believe that vegetarians have a lower cancer risk due to having plenty of fruits and vegetables in their diets and following a vegetarian diet makes it easier to get the daily recommended servings.
   
   
5. Reduces asthma symptoms
   It is believed that certain animal-derived foods can trigger inflammation or allergy responses that exacerbate asthma, so avoiding them can help prevent these responses. Moreover, plant-based foods are high in dietary fiber, which is known to improve lung function. It also improves your gut microbiome, which regulates your immune responses and prevents airway diseases.

Drawbacks of a Vegetarian Diet

1. Less convenient
   Following a vegetarian diet may not always be convenient as the meal choices may seem limited. However, more restaurants and stores are now providing a wide range of vegetarian options and you may consider finding tasty substitutes for certain foods by exploring grocery stores and supermarkets. You may decide to go vegetarian cold turkey or take a more gradual approach. You can start by going meatless one day a week and then slowly add more days once you get more used to the diet. This way, you can transition into a vegetarian diet without feeling overwhelmed and prevent potential nutrient deficiencies.
   
   
2. May still be unhealthy
   Food choices matter, whether you are a vegetarian or not. A vegetarian diet is not automatically healthy. While vegetarians tend to consume plenty of fruits, legumes, and vegetables, people who don’t like eating a lot of vegetables may end up consuming a lot of starchy foods and carbohydrates. Plus, many vegetarians rely on heavily processed foods, such as refined carbs, fried foods, and sweets. Although they may fall into the vegetarian category, they are far from healthy. To reap the benefits of a vegetarian diet, you must consume these items in moderation and emphasize more on whole plant-based foods.
   
   
3. Difficulty getting enough protein
   One of the most common arguments when it comes to a vegetarian diet is the lack of complete proteins. While plant-based proteins are cholesterol-free, few plant foods contain all nine amino acids, which are required to make complete protein in the body. People who eat meat don’t have to consider this as animal proteins are complete proteins.
   
   Experts recommend eating foods such as quinoa, soy, amaranth, chia seeds, tofu, hemp, and beans and rice, which contain all nine amino acids. In addition, it is advisable to consume different sources of protein every day to get all nine amino acids over time. 

Benefits of a Vegan Diet

1. May increase longevity
   A western diet, which is typically low in fruits and vegetables and high in saturated fats, is one of the main factors that lead to aging and diseases. Research suggests that switching to a plant-based diet may add years to your life expectancy. A strictly vegan diet can significantly reduce all causes of mortality and can help you live longer. This is because vegans eliminate all animal-based foods and usually replace them with a diet abundant in whole and nutritious plant-based foods. It is never too late to change your eating dietary patterns for good. In addition to choosing plant protein over animal protein, experts suggest eating fruits and vegetables of different colors and using unsaturated oils.
   
   
2. May reduce arthritis pain
   Animal-derived foods are likely to increase inflammation in the body, whereas plant-based diets are low in inflammatory triggers. Moreover, plant-based foods have a higher antioxidant, fiber, and probiotic content, which can help improve symptoms of rheumatoid arthritis, such as pain, morning stiffness, and swelling.
   
   
3. Promotes healthier skin
   Animal products are commonly linked to skin issues, such as acne, inflammation, and skin eruptions. On the other hand, a vegan diet includes lots of fruits and vegetables, which are loaded with nutrients and antioxidants required for healthy and glowing skin. It is also high in lysine and vitamin C, which boost collagen production. This helps to maintain skin elasticity and prevent wrinkles.
   
   
4. Aids weight loss
   Many studies have established that vegans generally have a lower body mass index than non-vegans. For this reason, people are increasingly switching to plant-based diets in hopes of losing weight. Plant-based foods are often lower in calories and fats than animal products, making it easier to cut down calories and maintain a healthy weight.
   
   A study conducted on 38 volunteers showed that even when the volunteers didn’t follow a vegan diet strictly, people who consumed a plant-based diet lost more weight than people on an omnivore diet ^[3].
   
   
5. Improved mood and energy 
   Eating a plant-based diet has been linked to improved mood and reduced anxiety. It is also known to improve your energy levels. This could be attributed to the fact that it doesn’t take as much energy to digest plant-based foods compared to animal products, which may slow you down. 

Drawbacks of a Vegan Diet

1. Social isolation
   Parties and social outings can be tricky for people who choose to be on a vegan diet. Veganism is yet to be accepted in some regions and people following a vegan diet may find it difficult to find friends as their lifestyle choices vary significantly from their peers. They may also have to deal with pressure and judgment from people who don’t understand veganism. As a result, vegans might end up being socially isolated. 
   
   
2. Takes more effort
   Following a vegan diet is not always easy as some foods will be harder to quit than others and you might have to refrain from your favorite dishes. You will often find yourself reading the nutrition labels of foods and explaining your preferences to waiters. Moreover, freshly baked goods may contain honey in their ingredients, which you will not know about unless there is a label. A general rule of thumb is that if you are in doubt about whether a product is vegan or not, assume that it’s not.
   
   Many people believe that being a vegan is expensive, but that depends on your food choices. Whole plant-based foods are not expensive. This myth is derived from the fact that ready-made vegan alternatives are expensive, such as vegan burgers and vegan brats. However, being a vegan does require more effort in terms of knowledge and time as you will have to cook your own meals more often.
   
   
3. Limited food choices
   A vegan diet can feel restrictive in the beginning and if you choose to go vegan, you can expect to eliminate a lot of foods from your diet. Moreover, many recipes call for at least one animal by-product. This may be limiting at first, but it gets easier down the line as you give it some time and learn more about your options.
   
   
4. May cause nutrient deficiencies
   A vegan diet can be very healthy, but there is a risk of potential nutrient deficiencies as it can be hard to get certain nutrients from plant-based foods that are abundant in animal products. This poses an increased need for vegans to look for alternative sources of certain nutrients.  Thus, it is important for vegans to follow a well-planned diet. 

Effect of Different Diets on Gut Health

Your gut is host to trillions of microorganisms, including gut bacteria, and fungi, which are mainly found in your large intestine. While some microbes are pathogenic, however most gut microbes present in the gut are friendly microbes that promote healthy digestion, boost immunity, regulate bowel movements, and control hormone secretion, among various other functions, and hence can be categorized as beneficial bacteria. When you alter the amounts of plant-based or animal-based foods in your diet, it influences the makeup of human gut microbiota.

Vegan Gut Health Diet

Since the vegan diet includes whole plant-based foods, it is typically higher in prebiotics which produce short-chain fatty acids. Prebiotics are special plant fibers that fuel the good bacteria in your gut. Confused between Prebiotics and Probiotics? Learn the difference from here! A healthy gut microbiome is one that is diverse and consuming a more plant-based diet is one of the best ways to achieve this. A vegan diet also tends to be high in anti-inflammatory foods and antioxidants that help reduce inflammation in the gut. On the flip side, it removes common probiotic foods, such as yogurt and kefir. Although non-dairy versions of these foods can be found, but they are not as readily available. 

Vegetarian Gut Health Diet

A vegetarian diet includes the benefits of a vegan diet to a large extent, such as high fiber intake and reduced inflammation. In addition, vegetarians can eat dairy products, such as yogurt, which is not only a good probiotic source but it is also a great protein source for people who don’t eat meat. Visit here to learn about more Probiotics Foods that are easy to find!

A study was conducted on 27 people, in which the stool samples of omnivores, vegetarians, and vegans were analyzed. The researchers found that the microbiome of vegetarians and vegans contained more microbial species that metabolized carbohydrates and vitamins when gut bacteria compared to omnivores. In addition, they found that a fiber-rich diet increased the production of other beneficial metabolites in the gut ^[4].

Non-Vegetarian Diet for Gut Health

Another study indicated that consuming animal proteins resulted in the proliferation of pathogenic bacteria that increase trimethylamine N-oxide (TMAO) levels, a microbial metabolite linked to neurological and cardiovascular disorders. On the other hand, vegetarians had a different microbiome that showed a diminished capacity to produce TMAO ^[5]. 

While animal proteins found in meat, seafood, and poultry are great sources of protein, a non-vegetarian diet can still be detrimental to your gut health. Animal products contain little to no fiber, which may cause potentially irreversible depletion of your gut microbiome. Besides, some meat eaters consume too much protein, which can lead to digestive issues. Animal-based products are loaded with saturated fats and increase inflammation in the gut, making you vulnerable to various kinds of diseases. The only time a non-vegetarian diet is recommended is when a person is suffering from gastrointestinal disorders (GI), such as irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO), as people suffering from these conditions lack enough good bacteria to digest the high amounts of fiber. As a result, they ferment in your gut leading to gas and bloating. For this reason, people with GI disorders are advised to eat more animal-based products till they heal from the condition.

Effects of a Vegetarian Diet on Other Health Aspects

1. Cholesterol
   A vegetarian diet that is high in soluble and insoluble fiber and low in saturated fat, trans fat, and cholesterol can help you reduce your cholesterol levels.
   
   A study conducted on 118 people found that a low-calorie vegetarian diet could reduce bad cholesterol levels more effectively than a Mediterranean diet ^[6].
   
   
2. Cardiovascular Health
   Compared to meat eaters, vegetarians tend to have lower blood pressure, healthier weight, improved cholesterol levels, and reduced incidence of type 2 diabetes, all of which are major risk factors for cardiovascular disease.
   
   
3. Immunity
   Vegetarians typically consume more fruits and vegetables than meat eaters, which contain various nutrients, antioxidants, and phytochemicals that are important for a healthy immune function. On the other hand, many non-vegetarians consume processed or charred meats that are high in advanced glycation end products (AGEs) and saturated fats, which may contribute to immune system dysfunction and systemic inflammation. Moreover, raw and undercooked meat may contain harmful bacteria, parasites, viruses, or chemicals that can make you sick.
   
   
4. Cognitive Functions
   The antioxidants in plant-based foods help fight off the free radicals that destroy brain cells. Eating a vegetarian diet can improve brain function and prevent dementia and various neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease. On the other hand, the consumption of saturated and trans fats may compromise brain health in the long run.
   
   
5. Muscle Mass and Strength
   Contrary to what some people may believe, there is no relation between non-vegetarian food and strength and a vegan diet is not detrimental to muscle strength. Moreover, it has been found that your body responds to plant-based proteins in the same way as it responds to animal-based proteins. This is to say that as long as you consume all nine amino acids from your diet, you can build muscle mass just as efficiently as a meat eater. 

When Can I Expect to See Results After Going on a Vegetarian Diet?

Although the gut microbiome quickly responds to changes in your diet and you will be able to notice minor changes in various health aspects in as little as a few weeks, researchers suggest that it can take about 4-6 months to improve your gut microbiome significantly. You must continue to follow the vegetarian diet for long-term benefits.

Supplementation to consider on a Vegetarian Diet

Since some nutritional deficiencies are more likely to occur on a meatless diet, vegetarians must ensure they meet their daily nutritional requirements. One way to ensure you are getting enough nutrients is to eat certain foods on a daily basis. You can also meet your nutritional needs by consuming fortified foods or through supplementation. You can tell whether you need supplements by analyzing your daily nutrient intake and having your blood nutrient levels measured. This is particularly important for women who are pregnant, nursing or trying to conceive.

Here are a few nutrients that vegetarians must consider.

1. Protein
   Protein is required for the maintenance of skin, muscles, bones, and organs as well as for the synthesis of various enzymes and hormones. You can get protein from foods, such as eggs, dairy products, soy products, legumes, whole grains, nuts, and seeds. The recommended daily allowance of protein for adults is 0.8 grams per kilogram of body weight.
   
   
2. Vitamin B12
   While vitamin B12 deficiency is fairly common, vegetarians and vegans are more likely to be deficient. Vitamin B12 plays an important role in many bodily processes, including the formation of red blood cells, protein metabolism, and keeping your nervous system healthy. A deficiency of vitamin B12 can cause anemia, neurological damage, infertility, and heart and bone disease. The recommended daily allowance for vitamin B12 is 2.4 mcg for adults. You can get vitamin B12 from foods such as milk, cheese, eggs, mushrooms, chlorella, nori, and nutritional yeast. 
   
   
3. Zinc
   Your body uses zinc to support immune function and metabolism and for the repair of cells. The mineral is required by every cell of your body to regulate, replicate, differentiate, and proliferate. In addition, it is a cofactor for more than 300 enzymes. The best sources of zinc include dairy, beans, oatmeal, spinach, yogurt, nuts, and seeds. The recommended daily allowance for zinc is 8-11 mg for adults women and men, respectively. 
   
   
4. Iodine
   Iodine is important for the production of thyroid hormone, which regulates your metabolism. A deficiency of iodine can lead to hypothyroidism. This can cause problems, such as fatigue, weight gain, dry skin, forgetfulness, and depression. The recommended daily allowance of iodine is 140-150 mcg for adults. Sources of iodine include seaweed, kale, strawberries, whole grains, dairy products, and iodized salt.
   
   
5. Omega-3 fatty acids
   Omega-3 fatty acids are required for many biological functions, such as boosting immunity, reducing inflammation, and protective roles against heart disease and other conditions. They are also important for metabolic, cognitive, eye, and joint health.
   
   There are three types of omega-3 fatty acids:
   1. Alpha-linolenic acid (ALA),
   2. Eicosapentaenoic acid (EPA), and
   3. Docosahexaenoic acid (DHA).
   
   Sources of APA include seaweed, algae, nuts, seeds, and leafy greens. Although seaweed and algae contain EPA and DHA, they are mainly found in animal products. EPA can be synthesized from ALA and DHA if they are present in sufficiently large amounts in the body. The recommended daily allowance of omega-3 fatty acids for adults is 200-300 mg.
   
   
6. Iron 
   Iron is an important mineral required to transport oxygen and nutrients to tissues and for DNA synthesis. Vegetarians can get non-heme iron from foods such as artichokes, dairy, egg yolks, leafy greens, beans, lentils, and dark chocolate. However, non-heme iron is not as readily absorbed as heme iron, which is only found in meat, fish, and poultry. Thus, vegetarians can benefit from iron supplementation, if required. The recommended daily allowance of iron is 12 mg for adult women and 16 to 18 mg/day for adult men.
   
   
7. Vitamin D
   Vitamin D helps in the absorption and retention of calcium and phosphorus, both of which are important for bone health. It also influences other processes, such as memory, mood, muscle recovery, and immune function.
   
   The recommended daily allowance of vitamin D for adults is 15 mcg (600 IU). You can get vitamin D from egg yolks, cheese, mushrooms, and from sun exposure.
   
   
8. Calcium
   Calcium is an important mineral for bone and teeth health. It is also necessary for nerve signaling, muscle function, and heart health. The recommended daily allowance of calcium is 1,000 mg per day for adults. Sources of calcium include dairy products, kale, bok choy, turnip greens, mustard greens, chickpeas, broccoli, and watercress.

Conclusion

A vegetarian diet is highly beneficial for optimal gut health and overall well-being if followed correctly. There are many types of vegetarian diets and what you eat on a vegetarian diet depends on the type of diet you follow. Once you have decided which foods you want to avoid, you must plan your diet so that you are able to meet your daily nutritional requirements. Consuming a wide range of foods can make it easier for you to get all the nutrients you need. 

If you are a non-vegetarian considering switching to a vegetarian diet, it is important to approach vegetarianism with an open mind. Like everything else, it will get easier with time and practice.  Being a vegetarian exclusively is not necessary and including more plant-based foods in your diet is a win all around. So even if you don’t eat a strictly vegetarian diet, you can benefit a lot from limiting your meat intake, and to derive all the good bacteria that are usually found in plant-based foods, you can add a Gut health Supplement, here is the List of Top 10 Gut Health Probiotic and Prebiotics Supplements.

References

1. A G Marsh, T V Sanchez, O Michelsen, F L Chaffee, S M Fagal, Vegetarian lifestyle and bone mineral density, The American Journal of Clinical Nutrition, Volume 48, Issue 3, September 1988, Pages 837–841, https://doi.org/10.1093/ajcn/48.3.837
   
   
2. Tantamango-Bartley Y, Jaceldo-Siegl K, Fan J, Fraser G. Vegetarian diets and the incidence of cancer in a low-risk population. Cancer Epidemiol Biomarkers Prev. 2013 Feb;22(2):286-94. doi: 10.1158/1055-9965.EPI-12-1060. Epub 2012 Nov 20. PMID: 23169929; PMCID: PMC3565018.
   
   
3. Moore WJ, McGrievy ME, Turner-McGrievy GM. Dietary adherence and acceptability of five different diets, including vegan and vegetarian diets, for weight loss: The New DIETs study. Eat Behav. 2015 Dec;19:33-8. doi: 10.1016/j.eatbeh.2015.06.011. Epub 2015 Jul 2. PMID: 26164391.
   
   
4. https://microbiomepost.com/how-a-vegetarian-diet-influences-the-gut-microbiota/
   
   
5. Tomova A, Bukovsky I, Rembert E, Yonas W, Alwarith J, Barnard ND, Kahleova H. The Effects of Vegetarian and Vegan Diets on Gut Microbiota. Front Nutr. 2019 Apr 17;6:47. doi: 10.3389/fnut.2019.00047. PMID: 31058160; PMCID: PMC6478664.
   
   
6. Sofi F, Dinu M, Pagliai G, Cesari F, Gori AM, Sereni A, Becatti M, Fiorillo C, Marcucci R, Casini A. Low-Calorie Vegetarian Versus Mediterranean Diets for Reducing Body Weight and Improving Cardiovascular Risk Profile: CARDIVEG Study (Cardiovascular Prevention With Vegetarian Diet). Circulation. 2018 Mar 13;137(11):1103-1113. doi: 10.1161/CIRCULATIONAHA.117.030088. Epub 2018 Feb 26. PMID: 29483085.