Hello my beautiful bags of sentient microbes! This week I'm going to cover: how to choose a fiber supplement (trust me I've tried them all lol), what microdosing weight loss injections actually does and how walking is better than running (super controversial I know!)

Your Guide to Fiber Supplements 

Fiber isn’t just about keeping you regular. It’s the bedrock (or should be) of your diet…fueling your gut microbes, training your immune system, balancing blood sugar, lowering cholesterol, and even protecting against conditions like type 2 diabetes and bowel cancer.

But here’s what I had wrong for years… fiber isn’t one single nutrient. It’s a whole family, with different types that behave in different ways. Some bulk and soften stool, others feed your “good” gut microbes, and some help lower cholesterol or smooth out blood sugar spikes. That’s why “just eat more fiber” can feel confusing… it matters what kind.

And when food alone isn’t cutting it on some days (and for 95% of people, it isn’t), supplements can help bridge the gap in many cases and be a convenient go-to… sort of like a protein shake (but for your gut)

What fiber supplements are (and aren’t)

Fiber supplements are concentrated forms of plant fibers, usually in powders, capsules, or gummies.

They don’t replace the 26,000+ plant compounds in whole foods. Food first, always. But supplements can still play an important role, especially if you’re short on time, travel a lot, or struggle to hit 30g of fiber daily. Think of them like a multivitamin for your gut… not a replacement, but a reliable backup.

My 5 rules for choosing fiber supplements

1. Food first, supplements second → Whole foods bring vitamins, minerals, and polyphenols you can’t bottle.
   
   

2. Pick based on goals → Constipation? Blood sugar? Gut diversity? Different fibers work differently.
   
   

3. Start low and go slow → Give your gut microbes time to adapt.
   
   

4. Listen to your gut → Gas, bloating, cramps: Adjust dose or fiber type.
   
   

5. Drink water → Especially if using bulking fibers like psyllium.
   
   

Popular fiber types (and how they work)

• Psyllium husk → Bulks stool and eases constipation. Great for regularity, but limited effect on your microbiome and very questionable mouth feel (gooey)
  
  

• Inulin / FOS → Prebiotic fibers that feed good bacteria, but often cause bloating (especially in IBS) as they ferment way too rapidly. Tried this, not a fan.
  
  

• GOS (Galactooligosaccharides) → A gentler prebiotic that supports gut microbes without as much discomfort, but it’s not vegan (dairy source).
  
  

• PHGG (Partially Hydrolyzed Guar Gum) → Gut-friendly, dissolves clear, well-tolerated even in sensitive guts, one of my favourites.
  
  

• Resistant starch → Found in green bananas or cooled potatoes; supports the microbiome deeper in the colon. Just a note, supplements containing resistant starch can be a touch intense especially on sensitive guts. I’ve generally tried to keep my resistant starch content from foods alone.
  
  

• Polydextrose → Adds stool bulk and moves things along, with less gas than other fibers. It is however synthetic and not from a plant source.
  
  

The tolerance factor

Not every gut reacts the same. Genetics, existing microbiome, and health conditions all influence how you respond. If you’re sensitive, start with gentler fibers like PHGG or psyllium, then slowly layer in other prebiotics. Always increase gradually over 2–4 weeks.

And spread intake across meals for a smoother ride.

The “bottom” line

Fiber supplements aren’t a silver bullet, but they’re a smart way to fill the gaps modern diets leave behind. Used right, they:

- Keep you regular
- Feed your microbiome
- Support cholesterol + blood sugar control
- Help reduce long-term disease risk

The key is choosing the right blend and using it consistently.

P.S. Why I created LOAM

After years of trying over 60+ fiber supplements, I kept running into the same problems: gritty texture, bloating, underdosed science, or single-fiber formulas that miss the bigger picture.

That’s why I created LOAM; a precision prebiotic fiber blend designed with diversity, clinical research, and gentle tolerability in mind. It’s built from multiple diverse and unique fibers to not just minimise bloating but feed your microbiome across the entire colon without overwhelming your gut.

👉 Click here to join the waitlist for exclusive early access (yes, for those asking it will be available in the USA!).

P.P.S if you sign up at www.loamscience.com you’ll also get weekly tips to improve your gut and microbiome health too! :)

Why Walking Beats Running for Long-Term Heart Health

When people think about exercise for heart health, running usually takes center stage. Sweaty, intense, heroic. 

Walking… meh it feels almost too ordinary.

But for long-term cardiovascular health, walking may actually do more for your arteries than running ever could.

1. Volume beats intensity

Sure, running is powerful for aerobic fitness. It spikes your heart rate, strengthens your heart muscle, and delivers quick cardiovascular benefits.

But you don’t run for six hours a day. Walking, on the other hand, sneaks into your life in ways running can’t; errands, commuting, pacing on phone calls, strolls after dinner (aka fart walk).

Over the course of a year, you’ll almost certainly log more mileage walking than running. And when it comes to vascular remodeling (the way your arteries adapt and stay resilient), total time under stress matters more than occasional bursts.

2. The “sink model” for cholesterol clearance 

Imagine your bloodstream as a sink.

• The basin is your blood plasma.
  

• The water filling it is LDL cholesterol and other lipoproteins.
  

• The drain is your body’s clearance system.
  

• And here’s the key bit: the sink is powered by a hydraulic foot pump; every time your muscles contract, they give the pump a squeeze, helping cholesterol particles move along.
  

Now, if the water just sits there, it stagnates. Those LDL particles hang around, get remodeled into smaller, denser, more atherogenic forms; i.e  the very ones most likely to clog arteries.

Walking acts like frequent, consistent pumping of the drain. Every step clears out just a bit more water. And when you’re walking throughout the day, you’re constantly keeping the system moving.

Running gives you powerful pumps… but only for a short while. Then the pump stops for the rest of the day. For lipid clearance, that’s less effective than the low-level, chronic signal of walking.

3. The evolutionary signal your arteries crave

Our arteries evolved under conditions of constant, low-level movement. Not sprints, not HIIT classes, but hours of daily walking, foraging, migrating, carrying.

This steady movement creates chronic shear stress on the inner lining of your arteries; a gentle, sustained signal that keeps blood vessels elastic, resilient, and anti-inflammatory.

Running does provide vascular shear stress, but it’s episodic. Walking provides it for hours each day, the way our biology was designed to receive it.

4. Why “exercise can’t replace walking”

A common misconception: “If I run or hit the gym, I don’t need to worry about steps.”

That’s only half true. Intensity does replace walking for certain things; like aerobic conditioning and VO₂ max.

But there are things intensity can’t replace:

• Lipid clearance (the sink model)
  

• Vascular remodeling (chronic shear stress vs. bursts)
  

• Lowering particle residence time (preventing LDL from becoming more dangerous)
  

Put simply: exercise is amazing, but walking is irreplaceable.

5. Actionables: How to walk smarter

• Distribute your steps. 10,000 steps all at once is good. But spreading them across the day is better for cholesterol clearance and vascular health.
  

• Use micro-walks. 5–10 minutes after meals improves post-meal blood sugar and keeps your “drain pump” active.
  

• Layer, don’t swap. Keep your workouts; strength, cardio, yoga… but layer walking on top as your baseline. Think of it as your body’s “always-on” maintenance program.
  
  

• Make it default. Walk for phone calls (game changer for me btw), take stairs, park farther away, set reminders to stand and stroll every hour.

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What Happens If You Microdose A Ozempic? 

Microdosing used to be a niche idea reserved for psychedelics or stimulants. Now it’s hit the world of GLP-1s (those weight loss drugs)

“Microdosing Ozempic” is trending everywhere from The New York Times to Reddit threads to Hollywood wellness circles. The concept is simple: take a lower-than-prescribed dose to see if you can still get the benefits, but with fewer side effects and lower cost.

People are experimenting for all sorts of reasons:

• To avoid nausea or digestive upset from the full dose
  

• To stretch out expensive prescriptions (since insurance often won’t cover these drugs unless you meet strict criteria)
  

• To manage appetite without wanting dramatic weight loss
  

While there’s no clinical research yet on the safety or long-term outcomes of microdosing GLP-1s, anecdotal reports are piling up. Patients say they feel calmer around food, snack less, and still notice modest weight changes. A few even describe unexpected “clarity” or reduced compulsive behaviors.

Is this the future of GLP-1 use? I genuinely think we are heading that way. But here’s what we know so far…

What “microdosing” actually means

In pharmacology, a true microdose is ~1% of a normal dose. That’s not what’s happening here. In practice, people are just taking smaller-than-standard amounts of semaglutide or tirzepatide… not “micro” by textbook definition, but lower, nonetheless.

The hope is to balance effectiveness with tolerability. In other words: just enough signal for appetite regulation and metabolic support, without overwhelming the body.

The side effect equation

GLP-1s slow gastric emptying, reduce appetite, and change how the brain responds to food cues. But they also cause GI side effects in many people.

Here are strategies doctors and patients have been using to stay ahead of the discomfort:

• Strength training  → Preserves lean muscle and bone density (crucial if you’re eating less).
  

• Protein focus  → Aim for ~1 g per lb of bodyweight daily to offset muscle loss and boost satiety.
  

• Gut support  → Add fermented foods (kimchi, kefir, sauerkraut) and prebiotic fiber to reduce bloating and constipation.
  

• Smaller, balanced meals  → eating little and often, steering clear of greasy or sugary meals that can worsen side effects.
  

• Hydration + electrolytes → Helps mitigate nausea, diarrhea, or constipation.
  

• Timing your dose  → Some find taking GLP-1 injections at night lets them “sleep through” peak nausea.
  
  

In short: if you’re going to experiment, the basics of muscle, gut, and nutrition become more important, not less.

The bigger question

GLP-1s are no longer fringe. They’re mainstream. And as usage spreads, the conversation has shifted: it’s less “Should you take one?” and more “How do you take one safely, sustainably, and personally?”

Could microdosing become the default approach? It would mirror what’s happening in other areas of medicine: precision dosing tailored to genetics, metabolism, and personal goals.

But until there’s data, the golden rule is simple: don’t self-experiment without medical guidance. These are powerful drugs, and every body reacts differently.

Takeaways for now

1. Microdosing GLP-1s is a trend, not yet science-backed. Proceed with caution.
   
   

2. Lifestyle still matters. Exercise, diet quality, sleep, and stress remain the foundations of metabolic health… GLP-1 or not.
   
   

Smaller, slower changes may actually be easier to sustain.

👋 Who are you again? I’m Karan Rajan - a doctor and curious explorer of all things health and wellness. I host the Dr Karan Explores Podcast and have written two books "This Book May Save Your Life" and "This Is Vital Information" and have just founded a microbiome company, LOAM Science 

Every Sunday, I share 3 interesting things about health, life and science to make your life easier, healthier and happier. (Disclaimer: I’m more your friend with health benefits. None of this is medical advice.) 

And oh, you if also feel strongly about some health things or just want to say hi? Hit reply... I’d love to hear it and hear from you!

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