Scott Hickle is all about data. Like many entrepreneurs in biotech, his approach is meticulous. He tracks nearly everything—from sleep with Oura to workout strain with WHOOP, as well as gut health and hydration through his Throne platform. So when he invited us to take part in his latest experiment, we were all in.
Normally, Scott sticks to a clean, whole-food diet. But for 30 days, he swapped his usual meals for ultra-processed foods to see exactly how his body would react.
What we learned might make you rethink what’s on your plate. Our Founder, Cheryl Sew How, and Healthcare Practice Director, Star Edwards, talked to Scott about his before-and-after Pro Gut Health Test results. Now, we’re bringing the details of that conversation to you. But first, here’s a bit of context for his experiment.
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Why he did it
After one particularly stressful day, Scott noticed his gut swing from constipation to diarrhea within hours. If stress alone could cause that kind of reaction, he wondered, what would a month of ultra-processed food do?
Curious how that might play out, he set up a 30-day experiment, leaning into everything he knows about biohacking (a DIY approach to self-care that uses lifestyle tweaks and high-tech tools to improve health) to see how his gut and other aspects of his health would respond when he ate nothing but ultra-processed food.
For one month, he swapped his balanced, high-protein meals for an all-junk diet—frozen pizzas, fast food burgers, donuts, and packaged snacks. His goal was to isolate the impact of food on his gut and his overall well-being.
The plan: a month of ultra-processed foods
For 30 days, Scott only changed the quality of his diet—everything else, including his 3,200-calorie intake, exercise routine, sleep schedule, and hydration, stayed the same.
"I kept everything else constant. I wanted to know exactly how swapping nutrient-rich food for ultra-processed alternatives would affect my gut and overall well-being," Scott said.
To define ultra-processed, Scott set up three simple criteria:
- The grandma test: If the ingredient list included items his grandma (and grandpa, too) wouldn’t recognize or pronounce, it was classified as ultra-processed.
- The sugar and oil test: Foods high in added sugars or deep-fried automatically qualified—think fast food and crispy snacks.
- The shelf test: Products with an extended shelf life due to artificial preservatives and stabilizers were ideal, too.
Based on these standards, Scott ditched his fresh fruits, vegetables, and lean protein diet overnight. He even dedicated an entire day to only eating Krispy Kreme treats.
Junk food is designed to keep you hooked
If Scott's experiment has sparked your curiosity about the consequences of moving from occasional indulgence to a full-on processed-food diet, you're in good company.
Junk food is everywhere—and it’s engineered to be irresistible. Thanks to the hippocampus and amygdala, our brain links the flavors of ultra-processed foods to memories of comfort and reward, making that next bite even harder to resist. Our childhood obsession with burgers, fries, and soda? That’s your brain’s reward system at work.
Scott’s gut results: What changed?
Scott took his baseline sample with Tiny Health’s Pro Gut Health Test on May 31st—before the experiment—and repeated it after 30 days on his ultra-processed diet. Unlike our Gut Health Test microbiome analysis, this advanced practitioner-only test examines detailed stool chemistry markers—calprotectin, lactoferrin, and secretory IgA—to provide a comprehensive view of gut inflammation and barrier function. Practitioners also use the Pro Gut Health Test to detect more reactive, short-term changes.
Here's an overview of Scott's Baseline samples. Notice how his Needs Support red flags jumped from 3 to 8. That's only after a month of eating junk food. Imagine what 6 months or a year of unhealthy eating might do to his gut!
From an increase in disruptive microbes and a drop in microbial diversity to a rise in inflammation markers, his results show just how much his processed-food diet impacted his gut balance.
A rise in disruptive microbes
During Scott's experiment, his gut didn't get the nutrients it needed to support good bacteria, allowing less-desirable bacteria like certain types of E. coli and Salmonella to grow more than they should. His results show that his natural gut balance has tipped, with disruptive bacteria trending upwards. Some of these bacteria are linked to food that hasn’t been handled or cooked properly, which can lead to foodborne illness.
Disruptive Microbes in Scott’s results show that Salmonella enterica went from 0.00% on May 31 to 0.02% after one month. Streptococcus also jumped from 0.28% to 0.64%—more than double its original level. And Enterobacteriaceae spiked to 1.33% from 0.16% at baseline, revealing how quickly unfriendly bacteria thrive on a junk food diet. And how sensitive your gut microbiome is.
“In the Disruptive Microbes part of his results, red flags rose from 1 to 5. This tells us that your gut can get wrecked pretty quickly. It can also take a long time to repair,” Cheryl said.
Elevated inflammation markers
Scott’s gut lining was stressed. His test showed higher levels of calprotectin and lactoferrin, proteins the body releases when fighting inflammation. If left unchecked, gut inflammation can lead to bigger health issues.
Cheryl said, “Elevated calprotectin and lactoferrin levels are red flags. They indicate that the gut lining is irritated—a warning sign that, if ignored, could lead to more serious issues.” She went on to say that if Scott had continued on his diet, it could have led to inflammation in other parts of the body. Long-term, unchecked inflammation has the potential to contribute to the onset of a number of diseases.
Star added, "GI docs can use elevated calprotectin to screen for IBD, so it isn't to be taken lightly."
Akkermansia nosedived
Scott’s Akkermansia levels dropped from 0.24% to 0% —essentially disappearing.
“Akkermansia thrives on a diet rich in fiber, fruits, and vegetables. Cut those out, and its numbers fall. It’s a clear sign that your gut isn’t getting the support it needs,” said Star.
Food and mood (the gut-brain axis)
Scott kept daily logs of his mood, energy, and focus on a seven-point scale and noticed a steady decline. Friends and colleagues even remarked that he didn’t seem like himself.
Given what we know about the gut-brain axis, their comments aren’t surprising. Changes in your diet can affect your gut, which in turn influences how you feel. When gut imbalances disrupt GABA—a chemical that helps keep stress and anxiety in check—along with serotonin and other key neurotransmitters, it can throw you off.
One important insight came from Scott’s continuous glucose monitor. Although his average blood sugar levels remained normal, his body experienced dramatic spikes and drops after high-sugar meals.
It took a toll on his mood. “It wasn’t about my overall average. It was those sudden highs and lows that really affected how I felt,” Scott said.
Our body needs tryptophan to make serotonin, which helps regulate mood [1]. You can get it from foods like turkey, eggs, dairy, nuts, beans, oats, avocado, and bananas—none of which were part of Scott’s processed-food diet.
“Once I went back to real food, I got out of that brain fog quickly. It showed me that while some markers take time to fix, feeling better day-to-day is within reach,” he shared.
Quick changes like this make it clear that what you eat influences your mood, energy, and overall well-being—both directly and through its impact on your gut [2].
Scott’s diet tanked his testosterone levels
As part of his experiment, Scott used Function Health to measure his testosterone levels before and after switching to ultra-processed food.
Notice how his total testosterone dropped by 24%. While technically still in range, this kind of dip in such a short time is significant. A quarter of that loss was in free testosterone, the form his body actively uses.
His free testosterone drop was even more dramatic, falling from 180.9 pg/mL to 125.9 pg/mL—a 30% decrease in just 30 days. Free testosterone is the form your body can use immediately, while most testosterone is bound to proteins and not as readily available.
To understand how hormones affect your overall well-being, here are five ways ultra-processed foods can throw off your levels:
- Processed foods fuel inflammation – When your body is in a constant state of inflammation, it can disrupt testosterone production [3].
- Your gut microbiome takes a hit – Junk food may shift the balance of bacteria in your gut, and since your gut helps regulate hormones, that’s not great news [4].
- Blood sugar spikes throw off hormones – Eating a lot of refined carbs and sugar can send your blood sugar on a rollercoaster. Over time, this may lead to insulin resistance, which is linked to lower testosterone in men [5].
- Missing nutrients make a difference – A junk food diet is often low in key nutrients like zinc and magnesium—both essential for keeping testosterone levels steady [6].
- Stress hormones rise, testosterone drops – A diet high in processed foods can raise cortisol, your body's main stress hormone. When cortisol goes up, testosterone tends to go down.
A drop in testosterone can leave men feeling more tired and irritable, with changes in muscle strength and metabolism. For women, lower testosterone levels can also impact energy, mood, muscle tone, and metabolic health. Curious how your diet is affecting your testosterone? Function Health helps you track your hormones over time. Use this link to skip their waitlist.
The good news? A whole-food diet rich in protein, healthy fats, and fiber helps support your body in making the hormones it needs to keep you feeling your best.
The proof is in the poop
We have to mention Scott's bowel movements during his experiment—as they’re a direct reflection of what's happening in his digestive tract.
Using an AI-powered toilet camera that tracks and monitors waste, Scott’s Throne device logs revealed a clear pattern throughout the month: on a typical junk food day, his stool remained within a normal range. But on challenge days—when Krispy Kreme and heavily spiced foods were his go-tos—it flipped back and forth between diarrhea and constipation.
Scott said, “Some days, everything was fine. Others, my digestion was all over the place. The unpredictable swings were hard to ignore.”
If you can relate to those extremes and uncomfortable days, the Bristol Stool Chart can help you make sense of it. The scale sorts poop into seven types based on shape and consistency, making it easy to see if things are running smoothly or if issues like diarrhea or constipation are creeping in.
But a one-time snapshot isn’t enough. And guessing about your gut health isn’t empowering. Tiny+ Adult Membership gives you a proactive way to monitor your gut health over time and get to the root of microbiome imbalances.
Back on track: Scott’s gut health recovery
When the experiment ended, Scott was more than ready to return to his healthy diet - including fermented favorites like kombucha. Within days, “It felt like my body was recalibrating,” he said.
Still, his gut microbiome wasn’t going to snap back overnight—especially friendly bacteria like Akkermansia, which took a serious hit. While his calorie intake remained constant, the quality of Scott’s food dramatically affected his gut microbiome. As Cheryl and Star explained, it doesn’t take much for beneficial bacteria to drop and disruptive ones to rise within weeks. Your gut microbiome is sensitive, but it’s also resilient.
To turn his gut health around, Scott followed a personalized action plan based on his results. Cheryl and Star highlighted these key recommendations:
- Eat a variety of plant-based foods: Different fibers fuel different microbes, so mix it up with fruits, veggies, and whole grains. Cheryl also recommends rotating where you shop, noting that soil health can differ between stores and farmers’ markets. If you’re always buying broccoli from the same place, you might be missing out on the natural variety of nutrients you’d get by switching it up.
- Include fermented foods: Yogurt, kefir, kimchi, and sauerkraut to help replenish beneficial bacteria.
- Go for polyphenol-rich options: Berries, red cabbage, and green tea support beneficial microbes like Akkermansia.
- Use fresh herbs: Fresh herbs offer extra gut-friendly compounds. Cinnamon, for instance, has antimicrobial properties that may help keep disruptive microbes like Enterobacteriaceae in check [7].
- Stick to it: Gut recovery is a process—and steady, balanced nutrition is the best way to support your gut health. “It’s about consistency. One month of poor eating can throw off your gut, but returning to a wholesome diet will gradually restore balance. It takes time, but the effort pays off,” Star said.
One of Scott's biggest takeaways? Gut health isn’t just about avoiding junk food—it’s about giving your gut the nutrients it needs every day to thrive.
“I’ll never do this again”
When Scott set out to see how diet alone could impact his gut, he didn’t have to wait long for answers. His mood swings and digestive issues were immediate, and his fat composition took a hit, too—Scott’s visceral adipose tissue, the harmful kind linked to metabolic disease, increased. Then, the data from his gut health test confirmed just how much his microbiome had shifted—beneficial bacteria dropped, disruptive microbes surged, and inflammation markers spiked.
While our guts are sensitive, they’re also responsive—resilient, even. Getting back to real food led to quick improvements, but rebuilding his microbiome, especially lost bacteria like Akkermansia, takes time.
So, would he do it again? Not a chance.
“I’m not going to put myself through this experiment again. But it taught me a lot about how important it is to fuel your body with real food. When you know what’s happening inside, you can make better choices.”
Not sure where to start with healthier eating? A Gut Health Test gives you a baseline, and we’ll walk you through a personalized action plan.
