To further add to the confusion, it’s possible to technically follow most popular diet styles to the letter, and still be eating mostly junk, which is not good for the gut by any stretch of the imagination.
Getting to Know Paleo, Ketogenic, Vegetarian, and Vegan Eating
In order to figure out what all four diets might share, it helps to understand each of their basic philosophies:
- Paleo: This diet strives to emulate the way people ate during the Paleolithic period (before agriculture took hold), and it avoids any foods our ancient ancestors couldn’t have gotten their hands on—including processed foods, GMOs, artificial additives, processed sugar, vegetable oils, and most grains and legumes. What’s left on the menu for paleo enthusiasts is lots of fresh, non-GMO veggies, fruits, meats, fish, and healthy fats like avocado, ghee, and certain plant oils. The result is a diet that’s high in protein and healthy fats, and somewhat lower in carbohydrates.
- Ketogenic: Keto eating is actually very similar to paleo, but is more heavily focused on achieving a high fat/low carb ratio with the target numbers coming in at about 75% fat, 20% protein, and 5% carbohydrates. The goal of ketogenic diets is to put the body in a state of ketosis, where it burns fat for energy instead of carbs. Like those on a paleo diet, ketogenic followers avoid foods like grains, legumes, and processed sugar—and eat plenty of fresh veggies, meats, fish, and healthy fats. Unlike paleo eaters, however, they sharply limit their intake of fruits, fruit juices, starchy vegetables, and alcohol.
- Vegetarian: Vegetarianism is often thought of as a modern trend, but it’s actually a very ancient way of eating, dating back to at least the 7th century B.C.E. True vegetarians don’t consume any meat, poultry, or fish at all, but animal foods aren’t necessarily off the table entirely. Ovo-lacto vegetarians eat dairy and eggs, lacto vegetarians eat dairy but not eggs, and ovo vegetarians eat eggs but not dairy. No matter which type of vegetarianism one follows, what’s always allowed is lots of fresh fruits and vegetables, nuts, seeds, grains, legumes, and healthy fats—basically anything that doesn’t have a face.
- Vegan: Vegan diets take vegetarianism one step farther, adopting a completely plant-based diet that eliminates not only meat, poultry, and seafood—but also eggs, dairy, and all other animal foods, including honey and royal jelly. Some vegans also don’t use leather, wool, silk, or anything else that comes from animals in their daily lives. All vegetables, fruits, grains, legumes, nuts, seeds, and plant oils are fair game for vegans, allowing for a richly colorful and varied diet.
So Where’s the Common Ground?
On the surface, the differences between these four diets may seem irreconcilable, but it turns out that those who take a simple, holistic approach to food tend to share six distinct, gut-healthy habits, no matter which style of eating they follow. And the exciting news is that every one of these gut-healthy habits is completely compatible with paleo, keto, vegetarian, and vegan diets.
1. Enjoying an abundance of prebiotic-rich plants
Vibrant health truly begins in the gut, and getting enough prebiotic fiber (the type of fiber found in most plant foods) is essential for keeping your diverse microbial community strong. You see, your friendly gut bacteria need food to survive, thrive, and multiply—and it’s that prebiotic plant fiber that provides their perfect nutrition. Getting all the prebiotics your good gut bugs crave keeps you at the top of your game in countless ways, including supporting comfortable digestion, sunny moods, robust immunity, strong bones, weight management, and healthy aging.1,2,3,4,5,6,7
Vegan, vegetarian, paleo, and keto diets may not all agree about which specific plants one should eat, but whether or not your meals include fruit, grains, or beans, there’s plenty of prebiotic-rich plant foods available in all four diets—and that translates into a well-nourished team of friendly microbes.2. Including cultured and fermented foods
Whenever you dig into some fresh sauerkraut, spicy kimchi, exotic natto, or just a bowl or organic yogurt, you’re getting a gut-boosting infusion of beneficial flora with every bite. That’s because the process of culturing and fermenting not only keeps foods fresh—it also transforms them into a delicious source of probiotic bacteria that replenish and diversify your microbiome. Gut-healthy fermented foods offer other benefits as well, and may even increase the nutritional content of certain foods and help you absorb more iron.8,9
There are plenty of fermented and cultured food choices in all of the diets we explored. Paleo and keto eaters will appreciate the minimal carb content in fermented vegetable dishes (like kimchi), many of which are also vegetarian and vegan! Dairy yogurt and kefir are allowed in vegetarian, keto, and some paleo diets—and plenty of vegan plant-based yogurts are also available.3. Avoiding processed and junk foods
Anyone who’s adopted a vegetarian, vegan, paleo, or keto diet for health reasons can easily agree that it’s wise to steer clear of heavily processed foods, which can be packed with all kinds of unhealthy fats, additives, preservatives, and GMOs that could harm your microbiome.10 Not only are most of these processed and deep-fried foods almost devoid of any natural nutrition, they also tend to feed and strengthen your undesirable gut bacteria—while effectively starving out the good guys. Genetically modified organisms may make things even worse by getting inside the DNA of your gut bacteria and changing the way they function.114. Avoiding refined sugars
There may be some dispute between the keto camp and other diets about the value of naturally occurring sugar in fruit, but staying away from refined sugar and high fructose corn syrup is another gut-healthy habit that wellness enthusiasts from the paleo, keto, vegetarian, and vegan schools of thought can all get behind. Refined sugars are terrible for your gut because (much like processed and junk foods) they excel at nourishing all the types of microbes you don’t want to have on board.12 And as the bad guys gain a foothold in your gut, your beneficial bacteria are starved and crowded out.5. Embracing healthy fats and avoiding trans fats
Science is finally revealing that not only is fat not evil, it’s essential for maintaining microbial and overall wellness. The trick is knowing which fats are good for you and which aren’t. Trans fats, for example, are disastrous for the gut, leading to a decrease in beneficial bacteria and an increase in harmful strains.13 Healthy fats, on the other hand, can help maintain a strong gut barrier to keep your friendly flora thriving, and some even help increase the population of your tiny good guys.14 Including healthy fats in any diet can also support healthy weight management, brain function, immune function, and vitamin absorption.15,16,17,18
Paleo, keto, vegetarian, and vegan enthusiasts will have no trouble ditching the bad fats and finding healthy fats that fit with the way they eat—even if they don’t eat the same healthy fats as their friends who follow different diets. Some excellent choices include nuts, seeds, avocado, grass-fed butter or ghee, coconut oil, omega-3 rich fish, flaxseed oil, and extra virgin olive oil.
6. Favoring whole, seasonal, and locally grown foods
Eating natural (preferably organic) foods in their whole, unprocessed forms is one of the best ways to love your gut—no matter which food categories your diet permits. Whole foods retain a valuable entourage of nutrients that work together synergistically so you can feel great from the inside out. And with most whole foods, you don’t have to worry about any dangerous artificial flavorings, additives, or preservatives. That’s why it makes sense to choose broccoli florets over canned broccoli soup, grass-fed organic beef over deli roast beef slices, fresh-picked strawberries over strawberry jam, and uncut grains over breakfast cereals.
When your whole foods are also seasonal and locally grown, that’s even better. Foods grown and harvested in their natural season that don’t have to travel far to your table tend to be more nutrient dense and contain lower levels of pesticides (or even antibiotics!) that could damage your microbiome.19,20,21
Ultimately, the very best diet of all is whatever style of gut-healthy eating best suits your unique body while reflecting your personal worldview. And including a high quality, time-released probiotic like PRO-15, along with some vegan organic prebiotic powder even further supports all your healthy food choices. Don’t you just love it when everybody wins?
1. J Nutr. 2012; 142(5):962-74 [PMID: 22457389]
2. Psychopharmacology (Berl). 2015; 232(10):1793-801 [PMID: 25449699]
3. Br J Nutr. 2013; 110(7):1292-303 [PMID: 23507173]
4. Am J Clin Nutr. 2009; 89(6):1751-9 [PMID: 19386741]
5. Allergy. 2009; 64(3):484-7 [PMID: 18507650]
6. Anaerobe. 1998; 4(6):257-66 [PMID: 16887651]
7. Biomed Res Int. 2017; 2017:59398118 [PMID: 29109959]
8. Int J Food Sci Nutr. 2004; 55(3):191-199 [PMID: 15223595]
9. Eur J Nutr. 2016; 55(1):373-382 [PMID: 25672527]
10. Nature. 2014; 505(7484):559-63 [PMID: 24336217]
11. Nat Biotechnol. 2004; 22(2):170-2 [PMID: 14755289]
12. Sci Transl Med. 2009; 1(6):6ra14 [PMID: 20368178]
13. Eur J Nutr. 2019; 58(7):2625-2638 [PMID: 30120538]
14. Int J Mol Sci. 2017; 18(12):2645 [PMID: 29215589]
15. JAMA. 2007; 297(9):969-77 [PMID: 17341711]
16. J Nutr. 2005; 135(3):431-6 [PMID: 15735074]
17. Am J Clin Nutr. 2004; 80(2):396-403 [PMID: 15277161]
18. Neurology. 2012; 78(9):658-64 [PMID: 22371413]
19. British Food Journal.1997; 99(6): 207-211
20. Genome Biol. 2017; 18(1):8 [PMID: 28115022]
21. NPJ Biofilms Microbiomes. 2017; 3:17001 [PMID: 28726854]
*These statements have not been evaluated by the Food and Drug Administration (FDA). These products are not intended to diagnose, treat, cure, or prevent any disease.