Probiotics vs Prebiotics: When to Use Which

Why is your gut the master switch for mood, metabolism, and better sleep?

Angela sits down with gastroenterologist and New York Times bestselling author Dr. Will Bulsiewiczto unpack the gut–circadian connection, why morning light can trigger a “regularity reset,” and the four nutrition pillars that rebuild your gut barrier and lower inflammation, without a restrictive diet.

You’ll hear when fiber helps (and when it can backfire), fermented foods vs. probiotics (and why “prebiotics first” often wins), meal timing for HRV and sleep, and how to recover your microbiome after stress, jet lag, or all-nighters.

What You’ll Learn:

• How morning light and cortisol shape gut rhythm, energy & focus

• Why over half of gut microbes follow a circadian clock

• The 4 gut-healing pillars: fiber, polyphenols, healthy fats, ferments

• Best time to eat fiber for blood sugar & bowel regularity

• When fiber backfires, and how to build tolerance slowly

• Fermented foods vs. probiotics: what really improves diversity

• How late dinners spike inflammation and disrupt sleep

• Brain fog & “leaky brain” - inflammation’s hidden link

• Gut shifts in menopause, and how to ease bloating & mood dips

• Easy resistant starch hacks for stronger digestion

Timestamps:

00:00 Intro: Rapid-Fire Gut Myths Debunked

02:20 Cortisol 101: How Morning Light Sets Your Gut’s Daily Rhythm

05:10 Gut–Brain Axis Deep-Dive: Serotonin, Vagus Nerve & Mood

08:00 Morning vs. Evening Routines: Light, Meditation, Melatonin & Sleep

11:00 Jet Lag & Microbes: Why Time Zones Wreck Your Gut and Blood Sugar

15:30 Meal Timing: Night Eating, Triglycerides & Inflammation Peaks

20:50 4 Nutritional Pillars for an Anti-Inflammatory Microbiome

30:00 Fiber Targets & Safety

39:00 How Fast Can You Heal? Stress, Environment & a 4-Week Turnaround

42:10 IBD & Colon Cancer: Microbiome, Inflammation and Oral Bacteria

45:00 Artificial Sweeteners vs. Sugar: What’s Safer for Your Gut?

47:40 What is a Healthy Poop?

50:30 Brain Fog Explained: Leaky Brain, Inflammation & the BBB

53:20 Perimenopause & the Microbiome: Diet, Stress and Symptom Relief

56:10 Fermented Foods vs. Probiotics

1:08:00 Best Time of Day to Take Prebiotics

VALUABLE RESOURCES

A BIG thank you to our sponsors who make the show possible:

• Mitopure - Supercharge your energy and upgrade your mitochondria: http://timeline.com/ANGELA | Enter code ANGELA to save 10%• Hormone Harmony - go to https://lvluphealth.com/ANGELA | Use the code ANGELA at checkout for an exclusive 15% off

ABOUT THE GUEST

Dr. Will Bulsiewicz is a board-certified gastroenterologist and New York Times bestselling author focused on evidence-based, fiber-forward nutrition and microbiome health. His forthcoming book Plant Powered Plus (January release) maps an anti-inflammatory blueprint to repair the gut barrier and rebalance the immune system. He is also the founder and formulator behind 38TERA®’s Daily Microbiome Nutrition - a prebiotic blend of fibers, resistant starches, and polyphenols.

🌐 Website: https://theguthealthmd.com/

📖 Pre-Order Plant Powered Plus: https://theguthealthmd.com/plantpoweredplus/

📰 Newsletter: https://app.theguthealthmd.com/checkout/tghmd-collective-membership-1

🌐 38TERA®: https://38tera.com/

📱 ZOE App: https://zoe.com/en-gb/app?shortlink=htblncyz&is_retargeting=true&c=Will%20B%20IG&pid=Organic%20Social&af_xp=custom&af_reengagement_window=30d&source_caller=ui

📱 Instagram: https://www.instagram.com/theguthealthmd/