Summertime has an uncanny way of creating magical moments that become woven into our sweetest memories. And whether your favorite recollections are of building sand castles, swimming in a sun-sparkled pool, or napping under the shady canopy of a backyard tree, the joys of summer are unquestionably some of the most evocative—and they are often intertwined with enjoying the tastiest foods of the season.
So as you set out to create your own sweet summer memories this season, take heart that many summer food favorites are so much more than just good for the soul—they’re also loaded with prebiotic fiber that will make your friendly gut flora jump for joy. That’s because prebiotic foods provide the perfect nutrition for your vast microbial community, helping to support desirable species like Bifidobacteria and Lactobacillus to help keep you feeling your best—and crowd out microbial strains you don’t want in your digestive tract.1
If you’re ready to take a yummy and gut-healthy bite out of the season, here are our top picks for summertime’s best prebiotic foods, along with ideas for healthy summer snacks and meals.
1. Wild Blueberries
Native to North America, this all-American fruit belongs to the same family as cranberries, huckleberries, and grouseberries. Blueberries are an excellent source of the antioxidant anthocyanin—and out of all the different types of blueberries, the one with the highest anthocyanin levels is the wild variety.2
Blueberries are in season all summer long, but unfortunately, wild blueberries are challenging to find in some areas of the country. If you’re not lucky enough to have them growing in your yard or in nearby woods, you may at least be able to purchase frozen organic wild blueberries at your local supermarket. No worries if you aren’t able to access wild blueberries though—all fresh, organic blueberries are still a wonderful gut-healthy addition to your summer menu.
Why your gut craves blueberries
Both human and animal studies suggest that the combination of prebiotics and antioxidants in blueberries shows good potential for strengthening the gut barrier and increasing numbers of beneficial gut flora, including Bifidobacteria (which helps us stay healthy as we get older).3,4
One very recent study even shows evidence that eating blueberries can soften the effects of an otherwise poor diet. A group of rats fed a diet high in unhealthy fats along with blueberry powder experienced an improved microbiome composition with increases in Bifidobacteria—along with better insulin sensitivity and stronger gut barriers.5
Great ways to enjoy wild blueberries
Wild blueberries are a tasty snack right out of the package (or off the bush!), but they also play well with other healthy foods in lots of summer treats. Include wild blueberries in your summer menu by:
• Featuring them in smoothies combined with lime, orange, broccoli, and fresh greens
• Pulsing them with frozen banana, plant-based milk, and vanilla to make a frozen blender dessert
• Sprinkling in fruit salads
• Mixing into unsweetened plant-based milk with a spoon of healthy oil (avocado and grapeseed oil are great choices) and some mint leaves for a cold summer fruit soup
2. Dandelion Greens
There’s something about happy yellow dandelions that coaxes out smiles on even the grumpiest days. Those sunny flowering plants growing almost everywhere during the summer season get their name from the French description of their signature serrated leaves: “dent de lion,” which means “lion’s tooth.” Dandelions come into season early in the summer, but can usually be found through the end of August.
Why your gut craves dandelion greens
The strong name dandelions bear suits them perfectly in terms of gut health as well as appearance—dandelion greens are a very powerful prebiotic.6 Each leaf contains 12-15% inulin, a type of prebiotic fiber that boosts gut health by increasing Bifidobacteria and Lactobacilli numbers while reducing unwanted bacterial strains.7,8
Great ways to enjoy dandelion greens
If you’ve never eaten dandelion greens, you’re in for a pleasant surprise. They have a light, ever so slightly bitter flavor that’s delicious both raw and cooked. You might want to try them:
• Tossed in fresh summer salads
• Blended into green smoothies
• Sauteed with garlic, healthy oil, and wild mushrooms
3. Walnuts
Walnuts may look like tiny brains, but they’re definitely not zombie food—even though the walnut tree seems practically immortal, living for up to 250 years. Perhaps that’s one reason that walnuts are one of humanity’s oldest known foods, and people have been eating them since around 7,000 B.C. Walnuts are actually considered “brain food” these days—not because of their brain-like appearance, but because they’re so rich in brain-healthy omega-3 fatty acids. These nuts don’t actually come into full season (which starts in September) until early fall, but luckily they’re still widely available all summer long.
Why your gut craves walnuts
Walnuts are a great source of prebiotic fiber, and a recent study revealed that rats fed diets that included walnuts had more diverse microbiomes with higher levels of friendly gut bacteria than those not fed the nuts, even though the control group’s diet contained the same amounts of fat, protein, and fiber as the walnut group.9 You don’t have to eat massive amounts of walnuts to reap their gut-boosting benefits—just about a half cup per day is enough to encourage positive microbial changes.
Great ways to enjoy walnuts
Walnuts add flavor, texture, and nutrition to almost any sweet or savory dish. Here are just a few of the many ways to include them in your diet:
• Snack on them by the handful
• Add to smoothies
• Create homemade walnut butter
• Sprinkle into salads
• Add to homemade breads, cookies, and pies
• Stir into pasta and casseroles
4. Avocados
Most of us think of avocado as a vegetable, but it’s actually a berry! Once an Aztec symbol of love and fertility, avocados are unable to self-pollinate and they grow in pairs. This well-loved fruit has a long growing season in California (where many U.S. avocados are grown) that extends from February until September, but their peak is during the summertime.
Why your gut craves avocado
Avocados contain lots of prebiotic fiber to nourish your microbial team—and they’re also rich in polyphenols, which feed friendly microbes as well. As if this wasn’t enough reason to eat avocados, these luscious fruits are also rich in three types of essential fatty acids that support microbial diversity and healthy gut function. In a recent animal trial, the gut microbiomes of rats fed avocado for six weeks were able to use the prebiotic fiber to produce short chain fatty acids, which help to regulate the immune system to keep it operating as it should.10
Great ways to enjoy avocados
The rich, creamy texture of avocados, along with their distinctive nutty flavor, makes them a family favorite any time of the day or night:
• Add to smoothies and sauces
• Make homemade guacamole
• Mash (or just eat right out of the peel!) and sprinkle with lemon pepper and a pinch of sea salt
• Slice up and throw into salads
• Include in homemade sushi rolls
5. Tomatoes
Like many foods we consider vegetables, all of the more than 7,500 varieties of tomatoes are technically fruits. Legally though, tomatoes are actually a vegetable! That’s because 1887 tariff laws charged a duty on vegetables but not fruits, so the U.S. Supreme Court ruled that tomatoes should be considered a vegetable, the rationale being that they’re served with meals rather than dessert. Pretty interesting, huh?
Since that time, tomatoes still suffer a bit of an identity crisis—they’re the official state vegetable of New Jersey, but they’re also the official state fruit of Ohio! Tomatoes are in peak season all summer, so take advantage of that full vine-ripened flavor while it lasts.
Why your gut craves tomatoes
Tomatoes have been getting lots of attention lately for their gut-healthy properties—the prebiotic fiber in both raw and cooked tomatoes nourishes helpful probiotics like Lactobacillus rhamnosus and Bifidobacterium bifidum, and it increases the ability of these friendly microbes to attach themselves to the intestinal wall.11
Tomatoes also seem to support gut balance even with an otherwise poor diet. Rats given tomato juice along with a diet high in unhealthy fats were still able to increase their numbers of Lactobacillus, which usually declines with this type of eating.12
Perhaps most exciting are the results of a new study that explored the interaction of tomatoes and beneficial gut microbes. This study showed that the lycopene and prebiotic fiber found in tomatoes worked in harmony to improve the gut—and that even though the probiotic L. reuteri seemed to prevent some antioxidants from being absorbed, the antioxidants in cooked tomatoes boosted the helpful activity of L. reuteri for an overall positive effect on gut health.13
While both raw and cooked tomatoes are gut-healthy foods, cooked tomatoes seem to have the strongest positive effect on the microbiome.
Great ways to enjoy tomatoes
These mouth-watering tomato ideas will spice up your summer in a gut-healthy way:
• Slice into salads and add to sandwiches
• Make a refreshing, cold gazpacho soup
• Mix with cilantro and onions to create a cooling salsa
• Create your own homemade tomato soups
• Lightly saute mini-tomatoes with avocado oil and parmesan cheese rind for a dynamite sauce
• Grill at barbecues
6. Peaches
What could be more satisfying than biting into a sweet, juicy peach on a hot summer afternoon? Although peaches have become an iconic part of American culture, they’re actually native to China and South Asia, belonging to the Rosaceae family, which also includes cherries, plums, nectarines—and believe it or not, almonds!
Peaches begin to come into season in May, but they peak in July and August, making peach picking and peach festivals perfect summer activities for the whole family.
Why your gut craves peaches
Peaches are a good source of pectin, a type of water-soluble, prebiotic fiber found in the cell walls of vegetables and fruits. Science shows that pectin helps boost gut health and increases the numbers of probiotic microbes like Lactobacillus.14,15 Peaches are also high in polyphenols, a type of antioxidant that supports the growth of friendly flora. Because of this, even drinking peach juice may help strengthen the microbiome and increase short chain fatty acid production.16
Great ways to enjoy peaches
No matter how you slice them, it’s hard to find a way to prepare peaches that isn’t incredibly yummy. Here are just a few of the countless delicious healthy snack ideas for peaches this summer:
• Blend into smoothies
• Feature in frozen desserts (mix with frozen bananas, plant-based milk, and a little ginger)
• Grill on the barbecue
• Slice into green salads or fruit salads
• Combine with tomatoes for a refreshing peach salsa
Bonus Summer Food: Chia Seeds
Originating in Mexico, chia seeds were once so highly regarded for their health-enhancing properties that they were actually used as currency. Aztec warriors believed that just a single spoonful could sustain them for an entire 24 hours. Chia seeds are available year-round, but they’re a wonderful addition to our summer prebiotic snack lineup because they have the capacity to hold lots of water to help maintain hydration on the hottest of days.
Why your gut craves chia seeds
The ancient peoples of Mexico were on the right track when they placed a high value on chia seeds—they’re a terrific prebiotic that’s also high in gut-healthy omega-3s. A study of the pre-hispanic Mexican diet (which featured chia seeds and other gut-boosting plant foods) found that this way of eating resulted in positive changes to the microbiome.17
Great ways to enjoy chia seeds
You can add chia seeds into almost any recipe for additional prebiotic power, nutrition, and texture. To get your whole family excited about chia seeds:
• Blend into smoothies and yogurt
• Create flavorful chia puddings with fresh fruit and almond milk
• Stir into oatmeal or other hot cereals on cool summer mornings
• Mix with water as an egg substitute
• Bake into muffins and cookies
• Soak a couple of tablespoons of chia seeds in water for 20 minutes, and then drink for long-lasting hydration
Even with the best diet, it’s important to understand that our modern world can be really tough on digestive health. That’s why you may also want to supplement with a high quality, time-released probiotic like PRO-15, and stir an organic prebiotic powder into your favorite smoothies and soft foods.
Including fresh, local prebiotic foods in your summer snacks and meals helps encourage a vibrant energy that allows you to make the most of this short, precious season. For more ideas about how to enjoy gut-healthy eating this summer and all year round, check out The Hyperbiotics Cookbook.
References:
1. A. Parnell, J., & A. Reimer, R. (2012). Prebiotic fiber modulation of the gut microbiota improves risk factors for obesity and the metabolic syndrome. Gut Microbes, 3(1), 29-34. doi:10.4161/gmic.19246/span>
2. Hosseinian, F. S., & Beta, T. (2007). Saskatoon and Wild Blueberries Have Higher Anthocyanin Contents than Other Manitoba Berries. Journal of Agricultural and Food Chemistry, 55(26), 10832-10838. doi:10.1021/jf072529m/span>
3. Lacombe, A., Li, R. W., Klimis-Zacas, D., Kristo, A. S., Tadepalli, S., Krauss, E., … Wu, V. C. (2013). Lowbush Wild Blueberries have the Potential to Modify Gut Microbiota and Xenobiotic Metabolism in the Rat Colon. PLoS ONE, 8(6), e67497. doi:10.1371/journal.pone.0067497/span>
4. Guglielmetti, S., Fracassetti, D., Taverniti, V., Del Bo’, C., Vendrame, S., Klimis-Zacas, D., … Porrini, M. (2013). Differential Modulation of Human Intestinal Bifidobacterium Populations after Consumption of a Wild Blueberry (Vaccinium angustifolium) Drink. Journal of Agricultural and Food Chemistry, 61(34), 8134-8140. doi:10.1021/jf402495k/span>
5. Lee, S., Keirsey, K. I., Kirkland, R., Grunewald, Z. I., Fischer, J. G., & De La Serre, C. B. (2018). Blueberry Supplementation Influences the Gut Microbiota, Inflammation, and Insulin Resistance in High-Fat-Diet–Fed Rats. The Journal of Nutrition, 148(2), 209-219. doi:10.1093/jn/nxx027/span>
6. McCabe, L., Britton, R. A., & Parameswaran, N. (2015). Prebiotic and Probiotic Regulation of Bone Health: Role of the Intestine and its Microbiome. Current Osteoporosis Reports, 13(6), 363-371. doi:10.1007/s11914-015-0292-x/span>
7. Samanta, A., Jayapal, N., Senani, S., Kolte, A., & Sridhar, M. (2013). Prebiotic inulin: Useful dietary adjuncts to manipulate the livestock gut microflora. Brazilian Journal of Microbiology, 44(1), 1-14. doi:10.1590/s1517-83822013005000023/span>
8. Ramirez-Farias, C., Slezak, K., Fuller, Z., Duncan, A., Holtrop, G., & Louis, P. (2008). Effect of inulin on the human gut microbiota: stimulation of Bifidobacterium adolescentis and Faecalibacterium prausnitzii. British Journal of Nutrition, 101(04), 533. doi:10.1017/s0007114508019880/span>
9. Byerleya, L.O., Samuelson, D., Blanchard, E. . . . Taylor, C.M. (2017). Changes in the Gut Microbial Communities Following Addition of Walnuts to the Diet. The Journal of Nutritional Biochemistry, 48. doi:10.1016/j.jnutbio.2017.07.001/span>
10. Paturi, G., Butts, C. A., & Bentley-Hewitt, K. L. (2017). Influence of Dietary Avocado on Gut Health in Rats. Plant Foods for Human Nutrition, 72(3), 321-323. doi:10.1007/s11130-017-0614-5/span>
11. Koh, J. H., Kim, N., Hwang, D., & Lim, Y. (2013). Effect of water-soluble fraction of cherry tomatoes on the adhesion of probiotics and Salmonellato intestinal epithelial cells. Journal of the Science of Food and Agriculture, 93(15), 3897-3900. doi:10.1002/jsfa.6255/span>
12. García-Alonso, F. J., González-Barrio, R., Martín-Pozuelo, G., Hidalgo, N., Navarro-González, I., Masuero, D., … Periago, M. J. (2017). A study of the prebiotic-like effects of tomato juice consumption in rats with diet-induced non-alcoholic fatty liver disease (NAFLD). Food & Function, 8(10), 3542-3552. doi:10.1039/c7fo00393e/span>
13. García-Hernández, J., Hernández-Pérez, M., Peinado, I., Andrés, A., & Heredia, A. (2018). Tomato-antioxidants enhance viability of L. reuteri under gastrointestinal conditions while the probiotic negatively affects bioaccessibility of lycopene and phenols. Journal of Functional Foods, 43, 1-7. doi:10.1016/j.jff.2017.12.052/span>
14. Chung, W. S., Meijerink, M., Zeuner, B., Holck, J., Louis, P., Meyer, A. S., … Duncan, S. H. (2017). Prebiotic potential of pectin and pectic oligosaccharides to promote anti-inflammatory commensal bacteria in the human colon. FEMS Microbiology Ecology, 93(11). doi:10.1093/femsec/fix127/span>
15. Gómez, B., Gullón, B., Yáñez, R., Schols, H., & Alonso, J. L. (2016). Prebiotic potential of pectins and pectic oligosaccharides derived from lemon peel wastes and sugar beet pulp: A comparative evaluation. Journal of Functional Foods, 20, 108-121. doi:10.1016/j.jff.2015.10.029/span>
16. Noratto, G. D., Garcia-Mazcorro, J. F., Markel, M., Martino, H. S., Minamoto, Y., Steiner, J. M., … Mertens-Talcott, S. U. (2014). Carbohydrate-Free Peach (Prunus persica) and Plum (Prunus domestica) Juice Affects Fecal Microbial Ecology in an Obese Animal Model. PLoS ONE, 9(7), e101723. doi:10.1371/journal.pone.0101723/span>
17. Avila-Nava, A., Noriega, L. G., Tovar, A. R., Granados, O., Perez-Cruz, C., Pedraza-Chaverri, J., & Torres, N. (2016). Food combination based on a pre-hispanic Mexican diet decreases metabolic and cognitive abnormalities and gut microbiota dysbiosis caused by a sucrose-enriched high-fat diet in rats. Molecular Nutrition & Food Research, 61(1), 1501023. doi:10.1002/mnfr.201501023