S1/E3: Your Second Brain: How Gut Health Controls Mood, Focus & Sleep

What if your “brain problem” isn’t in your brain at all? In this episode of Think Shift, host Mantazh Khanna (Brain Coach, PhD cand., MBA, MS) sits down with Jo Brownlow, Functional Medicine Health Coach, to unpack the gut–brain axis—and why your microbiome may be the missing link behind brain fog, anxiety, mood swings, low energy, and poor sleep. You’ll learn how the vagus nerve carries more signals from gut to brain than the other way around, why 90–95% of serotonin is produced in the gut, and how issues like SIBO, histamine sensitivity, low stomach acid, and dysbiosis can quietly derail cognition and mood. Jo shares her personal story (and her son’s), plus the exact testing and lifestyle shifts she uses with clients. What you’ll learn -The gut–brain connection, explained simply (vagus nerve, neurotransmitters) -How gut issues can show up as anxiety, low mood, and brain fog—even without digestive symptoms -Testing 101: GI-MAP stool tests, SIBO breath tests, red flags to watch -Root-cause protocol: remove → replace → (re)inoculate → restore → rebalance -Food & habit non-negotiables for a brain-friendly gut (fiber, omega-3s, eating hygiene) -Hidden blockers: low stomach acid, stress, poor sleep, alcohol, ultra-processed “healthy” wraps, carrageenan, gluten (for some) Actionable takeaways -Start with eating hygiene: slow down, chew well, avoid large drinks 30 mins before/after meals -Consider apple cider vinegar (if histamine-tolerant) to support stomach acid -Prioritize fiber diversity (veg, legumes, nuts, seeds) and omega-3s -Track symptoms vs. cycle (for women) and notice histamine responses to fermented foods -If issues persist, discuss GI-MAP or SIBO breath testing with a qualified practitioner Guest: Jo Brownlow, Functional Medicine Health Coach (Singapore) Host: Mantazh Khanna — Brain & Wellness Coach, Neuroscience Researcher, Cancer Survivor, PhD cand., MBA, MS 👉 If this episode sparked an “aha”: Subscribe, rate & review, and share it with someone who needs it. 📩 For speaking, coaching, or partnerships: [email protected] Chapters 0:00 Introduction 2:34 Jo’s story & the turning point 9:42 Gut–brain basics (vagus nerve, serotonin, dopamine) 15:20 Stress, IBS & why “rest-and-digest” matters 22:58 Microbiome: diversity, SIBO, histamine, leaky gut 28:54 Testing (GI-MAP, breath tests) & what results mean 34:45 Protocol & food non-negotiables 41:20 Foods to avoid & common pitfalls 45:02 Rapid-fire tips & closing Keywords gut brain connection, microbiome, brain fog, anxiety, low mood, serotonin in the gut, vagus nerve, SIBO, GI-MAP, functional medicine, histamine intolerance, low stomach acid, apple cider vinegar digestion, eating hygiene, leaky gut, mental clarity, sleep and gut health Hashtags #ThinkShift #GutBrainConnection #Microbiome #BrainFog #Anxiety #FunctionalMedicine #MentalPerformance #VagusNerve #SIBO #GutHealth #SleepBetter #StressResilience #NutritionScience #Serotonin