A Bedtime Snack That’s Actually Good For You? Yes, It's True
Late-night snacks are one of life’s small joys—a square of dark chocolate, a few spoonfuls of yogurt (who am I kidding, probably ice cream), or something crunchy to wind down the day.
But what if your bedtime snack could do more than satisfy cravings; what if it actually supported your gut and metabolic health, too?
That’s exactly what researchers set out to explore in a recent clinical trial looking at how one specific nighttime snack affects the gut microbiome in adults with prediabetes.
A nutty nighttime snack
The study, published in The American Journal of Clinical Nutrition, included ~50 adults with prediabetes, people whose blood sugar levels are elevated but not yet in the diabetes range.
For 12 weeks, participants ate about two ounces of pistachios as their bedtime snack, roughly two small handfuls. In another 12-week phase, the same participants swapped the pistachios for a typical carb-based snack, like crackers or toast (and yes, your beloved bedtime cookies fall into that category).
Researchers then analyzed stool samples taken before and after each phase to see how the two snack options influenced the gut microbiome. Here’s what they found.
Pistachios = healthier, more anti-inflammatory gut
After 12 weeks of nightly pistachio snacking, participants’ gut microbiomes looked noticeably different from when they’d eaten carb-based snacks. Specifically, the pistachio phase increased levels of beneficial bacteria like Roseburia and Lachnospiraceae, which are known for producing butyrate—a short-chain fatty acid that lowers inflammation, strengthens the gut lining, and supports metabolic balance.
At the same time, bacteria linked to poorer metabolic health, toxin buildup, and gut barrier dysfunction, such as Flavonifractor and Eubacterium, decreased.
These microbial shifts suggest that pistachios may help create a gut environment that’s more resilient and metabolically healthy, especially in people with blood sugar challenges. While the researchers didn’t see major changes in fasting glucose or insulin resistance over 12 weeks, the microbiome changes hint that improvements could emerge with longer-term habits.
Pistachios pack a metabolic punch
Pistachios are small but mighty when it comes to nutrient density. They’re rich in fiber (which feeds gut bacteria), plant-based protein, healthy fats, and a unique blend of polyphenols and antioxidants that help reduce inflammation.
Unlike many nighttime snacks that spike blood sugar, pistachios have a low glycemic impact, meaning they help stabilize energy and prevent overnight glucose dips that can disrupt sleep. Their combination of fiber, healthy fats, and amino acids also makes them a satisfying choice that supports muscle recovery and hormone balance.
The takeaway
Swapping your usual late-night snack for pistachios is a simple, evidence-backed move that could help your gut bacteria thrive and your metabolism stay balanced, especially if you’re looking to support healthy blood sugar levels.
Think of it as a reminder that nourishment doesn’t have to mean sacrifice—you can support your long-term health with small, satisfying choices. One mindful swap at the end of the day might be all it takes to wake up feeling a little more grounded, inside and out.