Microbes and Weight: Bacteroidetes vs Firmicutes

Your gut microbiome controls your brain chemistry, your stress response, your sleep, your metabolism, and your ability to lose weight, and most people have no idea how broken theirs actually is. 

• Watch this episode on YouTube for the full video experience: https://www.youtube.com/@DaveAspreyBPR 
• Get 20% off your next purchase of OMNi-BiOTiC with code ‘Dave20’ at: https://omnibioticlife.com/ 

In this episode, Host Dave Asprey and microbiome expert Hannah Kleinfeld break down the hidden gut science behind GLP-1 drugs, ADHD, HRV, histamine intolerance, SIBO, and why most probiotics you're taking are probably dead before they even reach your intestines. 

Hannah Kleinfeld is the co-founder and COO of Omni-Biotic US, a Yale and Harvard graduate, and a certified health coach whose personal battle with Lyme disease drove her deep into functional medicine and microbiome science. Omni-Biotic is the number one probiotic brand in Europe, used in hospital systems alongside antibiotic treatment, and is now bringing that clinical-grade research to the US market. 

Dave and Hannah go deep on the gut-brain axis, the vagus nerve, and how dysbiosis drives everything from brain fog and poor sleep optimization to inflammation, metabolic dysfunction, and compromised mitochondria. They cover how GLP-1 drugs slow gut transit time and trigger secondary dysbiosis, why most capsule probiotics rehydrate in stomach acid and fail, how short-chain fatty acids like butyrate cross the blood-brain barrier to regulate neuroinflammation, and how your gut bacteria directly control your heart rate variability, hormones, libido, and skin. This is biohacking your biology from the inside out, and it goes far deeper than supplements and fasting. 

You'll Learn: 

• Why GLP-1 drugs like Ozempic create secondary dysbiosis and what to do about it 
• How gut inflammation suppresses HRV, disrupts sleep, and accelerates aging 
• Why most probiotics rehydrate in stomach acid and never make it to your intestines 
• The gut-brain connection behind ADHD, brain fog, anxiety, and mood disorders 
• How dysbiosis sabotages weight loss by skewing Firmicutes to Bacteroidetes ratios 
• What the vagus nerve has to do with stress resilience and mitochondria health 
• How to support your microbiome through antibiotics, travel, and SIBO recovery 
• The histamine problem hiding inside popular probiotic strains 
• Why the first 1,000 days of a baby's life shape lifelong immunity and HPA axis function 
• How targeted probiotic formulations are changing functional medicine 

Thank you to our sponsors!    

• Suppgrade Labs | Grab your DAKE and Minerals 101 duo at shopsuppgradelabs.com and use code DAVEPOD for 15% off today
• Pre-order Arthur Brook's new book today at themeaningofyourlife.com. You can also see Arthur speak live at the 2026 Beyond Biohacking Conference 
• Fatty15 | Go to https://fatty15.com/dave and save an extra $15 when you subscribe with code DAVE
• BrainTap | Go to http://braintap.com/dave to get $100 off the BrainTap Power Bundle

Dave Asprey is a four-time New York Times bestselling author, founder of Bulletproof Coffee, and the father of biohacking. With over 1,000 interviews and 1 million monthly listeners, The Human Upgrade brings you the knowledge to take control of your biology, extend your longevity, and optimize every system in your body and mind. Each episode delivers cutting-edge insights in health, performance, neuroscience, supplements, nutrition, biohacking, emotional intelligence, and conscious living. 

New episodes are released every Tuesday, Thursday, Friday, and Sunday (BONUS). Dave asks the questions no one else will and gives you real tools to become stronger, smarter, and more resilient. 

Keywords: Hannah Kleinfeld, Omni-Biotic, gut microbiome, probiotics that work, GLP-1 gut damage, Ozempic side effects, secondary dysbiosis, gut brain axis, vagusnerve HRV, SIBO treatment, histamine intolerance probiotics, leaky gut inflammation, butyrate blood brain barrier, ADHD gut connection, probiotic capsules vs powder, antibiotic recovery, gut skin axis, microbiome sleep, Firmicutes Bacteroidetes weight loss, functional medicine gut health 

Resources:   

• Get 20% off your next purchase of OMNi-BiOTiC with code ‘Dave20’ at: https://omnibioticlife.com/ 

• Get My 2026 Clean Nicotine Roadmap | Enroll for free at https://daveasprey.com/2026-clean-nicotine-roadmap/ 

• Dave Asprey's Latest News | Go to https://daveasprey.com/ to join Inside Track today.  

• Danger Coffee: https://dangercoffee.com/discount/dave15   

• My Daily Supplements: SuppGrade Labs (15% Off)   

• Favorite Blue Light Blocking Glasses: TrueDark (15% Off)   

• Dave Asprey’s BEYOND Conference: https://beyondconference.com   

• Dave Asprey’s New Book – Heavily Meditated: https://daveasprey.com/heavily-meditated  

• Join My Substack (Live Access To Podcast Recordings): https://substack.daveasprey.com/ 

• Upgrade Labs: https://upgradelabs.com   

Timestamps: 

00:00 - Trailer 

01:10 - Intro

03:12 - Kids & Gas: Gut Imbalance in Children 

06:42 - Pills vs. Powder Probiotics 

07:28 - Omnibiotic Overview & Dave's Story 

10:44 - Probiotics & Heart Rate Variability

14:14 - GLP-1 Drugs & the Microbiome 

17:24 - Gut & Sleep Quality 

19:13 - Probiotics & SIBO 

27:47 - Gut Bacteria & ADHD 

29:55 - Gut, Libido & Fertility 

36:04 - Gut & Unusual Microbiome Facts 

43:22 - Histamine Intolerance & Probiotics 

51:58 - Kids' Microbiome vs. Adults' 

56:10 - Outro 

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.