Ep. 24: The Gut-Liver-Heart Connection Demystified — with Dr. Vivian Asamoah, Gastroenterologist

You’ve heard of the gut-brain connection — but what about the gut-liver-heart connection? In this episode, Dr. Regina Druz is joined by her friend and colleague Dr. Vivian Asamoah, an integrative gastroenterologist and hepatologist, to demystify how the trillions of microbes in your gut quietly shape your heart, brain, and metabolic health. They define the microbiome and dysbiosis in plain English, explore which conditions the microbiome most influences, and unpack a striking American Heart Association advisory linking gut bacteria to blood pressure. Then they turn to fatty liver — now renamed MASLD — explaining why it’s really a metabolism problem, how a ‘leaky gut’ feeds liver inflammation and the dyslipidemic triad, and which simple, foundational steps (starting with what to remove) can change the trajectory.

Watch on YouTube: A video version of this episode is available on the Own Your Heart Health YouTube channel. Subscribe to be notified of new episodes.

Episode Chapters

[00:00] Introduction & Meet Dr. Vivian Asamoah
[01:33] From Hopkins GI to Integrative Gastroenterology
[04:04] The Inflection Point: Reverse, Don’t Just Prescribe
[07:05] Microbiome 101: What It Is and Why It Matters
[14:14] Dysbiosis & the Conditions It Drives
[19:02] Stool Testing: Sequencing & the Shannon Index
[22:19] Diet & Diversity: Is There a “Best” Microbiome Diet?
[26:43] The AHA Microbiome-Hypertension Advisory
[32:00] Fatty Liver Reframed: MASLD & the Gut-Liver Axis
[38:00] The Dyslipidemic Triad & Leaky Gut
[40:34] Testing the Liver: FIB-4, FibroScan & Fibrosis
[48:06] Top Three: Remove Toxins, Move More + Closing

Transcript

[00:00] Introduction & Meet Dr. Vivian Asamoah

Dr. Regina Druz (00:02): Welcome to Own Your Heart Health. I’m Dr. Regina Druz, your holistic cardiologist. This week we’ll dive into common heart health concerns, uncovering root causes and unpacking scientific discoveries and controversies. The information provided does not constitute medical advice. Please contact your healthcare practitioner before making any changes that may impact your health.

Dr. Regina Druz (00:40): Welcome everybody — another happy Friday. I’m absolutely thrilled to be here with a great friend, mentor, and colleague, Dr. Vivian Asamoah. I’m an integrative cardiologist, and Vivian is an integrative gastroenterologist who is changing lives every single day — not just in Katy and Houston, Texas, but nationally and internationally. She’s a renowned speaker, a faculty member for the Institute for Functional Medicine, and she runs a phenomenal signature program for digestive issues from an integrative perspective. Welcome, Dr. Vivian.

Dr. Vivian Asamoah (01:20): Thank you so much for having me on, Dr. Druz. This is great.

[01:33] From Hopkins GI to Integrative Gastroenterology

Dr. Regina Druz (01:33): I’ll ask you the same question I ask all my guests: how did you grow up to be an integrative gastroenterologist?

Dr. Vivian Asamoah (01:50): It began in medicine. During my internal medicine residency at Johns Hopkins, my hepatology mentor told me, ‘V, I think you’d be a great gastroenterologist — you love procedures, internal medicine, and digging deeper.’ They offered me a GI fellowship at Hopkins, and it was a perfect match. The integrative side came from nutrition: I lectured second- and third-year medical students on nutrition — we need far more of it in medical school — and I gravitated to the dietitian and bariatric teams. Seeing the impact of nutrition on chronic disease made me realize it has to start upstream, in gastroenterology, long before things progress to surgery. So when I started practice, I brought dietitians in on day one.

[04:04] The Inflection Point: Reverse, Don’t Just Prescribe

Dr. Regina Druz (04:20): What was the inflection point — there’s always one.

Dr. Vivian Asamoah (04:30): For me it wasn’t a personal illness — it was my patients. Day to day, I noticed that continuing to prescribe wasn’t a sustainable solution; patients kept coming back dissatisfied, asking, ‘Do you really expect me to take this forever?’ I had to start thinking about how to reverse disease, not just manage it. I began reading my Hopkins mentor Dr. Gerry Mullin and other integrative gastroenterologists like Dr. Robynne Chutkan, looking for better answers. When I dove into functional medicine — root-cause, reverse, heal, sustainable — and implemented even the basic foundational strategies, I saw immediate results in my patients. I thought, this is the right place for me.

Dr. Regina Druz (05:50): That’s such a recurring theme on this show. What pushed me toward integrative cardiology was also my patients. I thought I was a pretty good cardiologist, but I wasn’t getting the results people really wanted — and I started seeing patients take their health into their own hands. As an integrative gastroenterologist, you sit on top of two huge areas reshaping not just GI but cardiology and longevity: the microbiome, and metabolic-associated fatty liver disease. Let’s start with the microbiome — can you give us baseline definitions? What is the microbiome, what is dysbiosis, and why are we even looking into it?

[07:05] Microbiome 101: What It Is and Why It Matters

Dr. Vivian Asamoah (07:30): When a patient asks ‘how healthy is my gut?’ they’re really asking about their microbiome. Thanks to the Human Genome Project and the microbiome projects of the last decade, we’ve learned this ecosystem may be even more important than our own human cells. It’s trillions of bacteria, viruses, fungi, parasites, and archaea that colonize us right after birth — mostly in the large intestine, but also the skin, mouth, nose, and other moist cavities. They help us digest and extract nutrients, balance the immune system, convert metabolites into neurotransmitters like serotonin and dopamine, and even metabolize the medications and supplements your physician gives you into their active forms. Without the microbiome, we really don’t exist — we depend on it.

Dr. Vivian Asamoah (10:30): So what is dysbiosis — and is it the same for everyone? Dysbiosis is an imbalance or dysregulation of the microbiome. We have families of bacteria and other organisms that should exist in balance — enough of the healthy ones, not too much of others — because it’s all about the interaction, the ratios, the balance. The hard part is defining the ‘gold standard’: microbiologists still can’t fully answer who has the perfect microbiome. What we do know is that the balance is primarily determined by what we eat.

Dr. Regina Druz (12:00): Hi everyone, it’s Dr. Regina here. I know there are contradictory opinions about nutrition for heart health and longevity — the discussion gets heated and confusing. Some push low-fat, low-cholesterol; others are fans of a ketogenic diet; and there are many voices urging vegan or vegetarian eating. To cut through the clutter, my team and I created Holistic Heart University: on-demand courses, nutrition and lifestyle resources, and supplement guidance to make healthy choices for your heart easier to understand. I’m especially proud of our open office hours and the Q&A feature where you can put us in the hot seat. Head to the show notes for the link and use promo code OWNER20 for 20% off our annual subscription. I’ll see you in office hours.

[14:14] Dysbiosis & the Conditions It Drives

Dr. Regina Druz (13:50): After decades of research, what are your top conditions where the microbiome clearly plays a major role — not just GI conditions like IBS or inflammatory bowel disease, but the systemic effects on insulin resistance, blood pressure, dementia, and depression?

Dr. Vivian Asamoah (14:30): The biggest impact I’m seeing right now — and I wouldn’t have said this five years ago — is everything related to the brain: Alzheimer’s, psychiatric disease, and evolving conditions like autism and ADHD, where we see strong patterns in the strains involved. In cardiology there’s clear evidence linking certain strains and their metabolites to disease. And in gastroenterology, the biggest impact is in functional GI disorders — irritable bowel syndrome, functional dyspepsia, chronic constipation — all the gut-brain-axis conditions. But in functional medicine it all spills over and interconnects: a single microbiome pattern can raise TMAO and the risk of hypertension or coronary disease, while that same profile raises the risk of metabolic liver disease, strokes, and vascular dementia. You can’t cleanly isolate them.

Dr. Vivian Asamoah (17:30): What about the microbiome and Alzheimer’s specifically? I recently spoke with a colleague who tests the oral microbiome; certain bacteria there produce toxins that cross the blood-brain barrier, drive neuroinflammation, and may contribute to Alzheimer’s. Is it a similar path? I’m not an Alzheimer’s expert, but I’m confident there are specific strains that drive inflammation and the deposition of particles in the brain — very likely similar to the patterns we see in cardiovascular disease.

[19:02] Stool Testing: Sequencing & the Shannon Index

Dr. Vivian Asamoah (19:02): You do a lot of stool testing to assess the microbiome. Can you explain what’s involved and whether there’s a gold standard? When it comes to comprehensive stool testing, there are different approaches. Some companies do only PCR — polymerase chain reaction — looking at perhaps 30 to 35 sequences (16S) in certain strains, which isn’t a complete picture. For a true bird’s-eye view you want whole-genome, next-generation sequencing, which captures the full array of what’s there. It’s excellent for bacteria — less complete for every strain of yeast — but it sees most of the bacteria.

Dr. Vivian Asamoah (21:30): Then you start with something called the Shannon Index, which compares your sample’s diversity to what a healthy microbiome looks like. Who defines ‘healthy’? Researchers assessing microbiomes globally, by age and region, looking at the main families and how much of each you have, and how diverse it is. It’s influenced by where you live, even your ancestry, and certainly by what you eat — a vegetarian’s microbiome differs from a carnivore’s — so those factors have to be taken with a grain of salt when defining the healthy standard.

[22:19] Diet & Diversity: Is There a “Best” Microbiome Diet?

Dr. Vivian Asamoah (22:19): There are heated debates between vegans, vegetarians, and Mediterranean eaters like me — does the research point to one best diet for the microbiome? Two things. First, cultures adapt and optimize their microbiome to what they’ve eaten over generations — if your ancestry is largely vegetarian, your microbiome adjusts to that; the microbiome of people eating mostly raw foods differs completely from those eating cooked. Second, diversity is essential: eating a wide variety supports all the families — Actinobacteria, Bacteroidetes, Firmicutes — in the right ratios. It’s all about interaction, ratio, and balance, which is why moderation and diversity matter most.

[26:43] The AHA Microbiome-Hypertension Advisory

Dr. Regina Druz (26:43): Just yesterday the American Heart Association released a science advisory on hypertension and the gut microbiome — not guidelines, but a summary of where the research leads. If you’re listening, you may want to jump to the video for this part. What surprised me: they highlight that salt interferes with Lactobacillus, so the salt-hypertension relationship may run partly through the microbiome. And they describe a resistant starch I’d never heard of — abbreviated HAMSAB — are you familiar with it?

Dr. Vivian Asamoah (28:00): Is it a resistant starch? Resistant starches are exactly what we recommend — green plantains, cooked-and-cooled rice and potatoes — because the bacteria feed on them to make short-chain fatty acids. You get the most microbiome modulation from these.

Dr. Regina Druz (28:30): That’s it — HAMSAB stands for high-amylose maize resistant starch modified with acetate and butyrate, the very short-chain fatty acids the bugs produce. In the trials it lowered systolic blood pressure by an average of about six millimeters of mercury — which sounds small, but every millimeter matters.

Dr. Vivian Asamoah (29:30): Absolutely. You can get these in research-grade powders, but ideally through food. For fiber, I aim for about 25 to 30 grams a day for women and 35-plus for men — and I emphasize natural, polyphenol-rich fibers for their antioxidant benefit, not just the fiber itself. I don’t routinely prescribe a daily resistant-starch percentage; instead, when I see significant dysbiosis — a skewed Bacteroidetes-to-Firmicutes ratio or low butyrate, propionate, and acetate — I’ll add a resistant-starch supplement, about one serving a day for three to six months, alongside food, to deliberately shift the microbiome. And, interestingly, butyrate itself appears to lower blood pressure — not just protect the intestinal lining and assist hormone clearance.

[32:00] Fatty Liver Reframed: MASLD & the Gut-Liver Axis

Dr. Vivian Asamoah (32:00): Let’s switch gears to that metabolically associated liver disease — what is it, and why are we seeing so much of it? This is where the microbiome’s impact on liver inflammation is clearest, and we’re seeing an explosion of fatty liver — about one in four people globally. The name was changed about four or five years ago. We used to call it non-alcoholic fatty liver, or, before that, even ‘cryptogenic’ — like a secret — and the old framing fixated on alcohol, which obscured the real root cause. Now we call it MASLD: metabolic dysfunction-associated steatotic liver disease. That name tells the truth — it’s tied to metabolic syndrome: high blood pressure, dyslipidemia, high triglycerides, insulin resistance, and waist circumference. I tell patients this is not a liver problem.

Dr. Regina Druz (35:39): It’s a metabolism problem.

Dr. Vivian Asamoah (35:45): Exactly. And it’s fundamentally a gut-liver-axis issue. We hear about gut-brain and gut-hormone connections, but one of the most important is the gut and the liver — they share the portal vein and communicate constantly. When there’s dysbiosis, you develop intestinal hyperpermeability — in plain English, a leaky gut — and microbial antigens and toxins like LPS filter out of the intestine, travel through the portal system straight to the liver, and trigger a cascade of inflammation, oxidative stress, and lipid dysregulation that feeds the fatty liver and steatohepatitis.

[38:00] The Dyslipidemic Triad & Leaky Gut

Dr. Regina Druz (38:00): As an integrative cardiologist I see the other end of this. We talk about the dyslipidemic triad, with the liver at its center: when someone is insulin resistant — even at the tissue level, before hemoglobin A1c rises — and free fatty acids are floating around, the liver packages them into ApoB particles. We see high triglycerides, elevated ApoB or LDL, low HDL, plus small dense LDL and remnant particles. But we also see it in people who aren’t strictly insulin resistant or fully metabolic-syndrome — and they usually have the leaky-gut situation, where chronic immune activation eventually makes them insulin resistant down the line.

Dr. Vivian Asamoah (39:01): Exactly — there are different causes of dysbiosis, and you have to ask what’s driving the imbalance in the first place.

Dr. Regina Druz (39:30): Hi everyone, it’s Dr. Regina here. Many of my colleagues and I are seeing patients arrive with self-ordered blood tests. When this trend started, I thought it would help — who doesn’t want more access to their health data? But too often self-ordered labs lead to more confusion and frustration: patients come in with a pile of results and are no better off. That’s why we created HeartWell Toolkits — a curated collection of at-home blood and genetic markers focused on heart and brain health that gives you the data you need to make informed, actionable decisions. You can order them at the shop on holisticheartcenters.com — the link is in the show notes. Use code TESTING10 for 10% off and free shipping.

[40:34] Testing the Liver: FIB-4, FibroScan & Fibrosis

Dr. Vivian Asamoah (40:34): I often run a FIB-4 — really a calculation from a few routine blood values that approximates the chance of liver fibrosis. Are you screening everyone, or only some patients? Honestly, knowing the many pathways to fatty liver, I almost want to screen everybody — it’s predominantly metabolic, but you also see dysbiosis, bile-acid and uric-acid issues, and even toxin exposures. We’re seeing fatty liver from persistent organic pollutants (POPs) and even food preservatives, which animal studies show alter the microbiome. Almost everyone walking into my practice has some fatty liver.

Dr. Vivian Asamoah (42:47): In the old days people waited for liver enzymes to rise — but that’s no longer justifiable, because you can have advanced liver disease with completely normal enzymes. We have to change that narrative, starting with primary care, and empower patients to know that normal bloodwork doesn’t rule it out. On ultrasound, fatty liver shows once more than about 5% of the liver is fat, graded mild, moderate, or severe.

Dr. Vivian Asamoah (44:20): Tell us about the better tests. FibroScan is excellent — the CAP score assesses steatosis (how much fat), and the elastography measures liver stiffness in kilopascals by sending a vibration wave and measuring what reflects back. Stiffness tells us how much scarring and fibrosis there is, because that scar tissue replaces healthy, functioning liver cells — cells with vital synthetic, clearance, and detoxification roles. And patients with MASLD are at increased risk of hepatocellular carcinoma, so it matters. We grade fibrosis from zero to four; a four means cirrhosis — roughly 85 to 90% of the liver scarred. So I’ll get a good ultrasound, then a FIB-4 regardless of enzyme levels, and if it’s above the cutoff, move to elastography to quantify the fibrosis.

[48:06] Top Three: Remove Toxins, Move More + Closing

Dr. Vivian Asamoah (48:06): As we close, what are your top three pearls for listeners wondering whether they have fatty liver or leaky gut — what should they do, test or no test? Go back to foundational. Number one, remove the toxins. Alcohol first — for a fatty liver it’s like gasoline on a flame.

Dr. Regina Druz (48:50): As a cardiologist, I see resistant hypertension, stubborn dyslipidemia, even atrial fibrillation that, when you dig, traces back to toxin load. And the old reassurance that one drink a day for women or two for men is ‘fine’ is, frankly, nonsense — the World Health Organization is clear that alcohol is a toxin at any dose.

Dr. Vivian Asamoah (50:00): Super important. The second toxin we don’t talk about enough is high-fructose corn syrup — clearly associated with fatty liver, and why we’re seeing severe fatty liver in 13- and 14-year-olds who’ve been given soda since age two. (The uric-acid connection is real here too.) I’d add ultra-processed foods — anything made in a factory, heavily preserved, that you can’t grow and cook yourself. Often we heal by removing, not adding. The second emphasis is exercise: even 30 to 45 minutes of moderate activity helps reverse metabolic dysfunction and fatty liver, ideally combining continuous moderate movement, some high-intensity intervals, and weight-bearing resistance training to use insulin properly.

Dr. Regina Druz (52:00): There’s huge emphasis now on resistance training and muscle mass — all important — but I see patients sacrifice their Zone 2 aerobic training to do it, and that’s a mistake: you need Zone 2 to maintain VO2 max for cardiac performance, healthy aging, and metabolic flexibility. Vivian, this has been phenomenal. Please share where listeners can learn more about the microbiome, leaky gut, fatty liver, and your signature program.

Dr. Vivian Asamoah (53:18): Thank you so much for having me — I feel like we could talk forever. You can find me and my practice, Houston Gastro Institute, and my signature functional gut program online; the links are in the show notes.

Dr. Regina Druz (53:40): To the professionals listening: if you’re thinking of launching a cardiometabolic or integrative cardiology program in your practice, we can help. Holistic Heart Centers helps physicians expand into hybrid or concierge services — head to the show notes and click the application link; your intro call is entirely free. Ready to schedule a practice review? Use code DOC10 for 10% off our Practice Power Hour, a 60-minute coaching session. Thank you for tuning in to Own Your Heart Health with Dr. Regina Druz. This podcast is powered by Holistic Heart Centers. If you enjoyed the show, please rate and review us on your favorite platform, and visit holisticheartcenters.com and subscribe to our YouTube channel. See you next week.

Frequently Asked Questions

What is the microbiome, and what is dysbiosis?

The microbiome is the vast community of microbes — trillions of bacteria, viruses, fungi, parasites, and archaea — that live with us, mostly in the large intestine, and begin colonizing us right after birth. Dr. Asamoah explains that they’re essential partners: they help digest food and extract nutrients, balance the immune system, produce neurotransmitters like serotonin and dopamine, and even activate the medications and supplements we take. Dysbiosis is an imbalance or dysregulation of that community — too few helpful organisms, too many of others, or the wrong ratios — which disrupts those functions. A key point she makes is that there’s no single agreed ‘gold standard’ microbiome (it varies with diet, ancestry, and geography), but diversity and balance are what matter most, and they’re driven largely by what you eat. This is educational information, not individualized medical advice.

What does fatty liver (MASLD) have to do with my heart?

A great deal, because they share the same metabolic roots. MASLD — metabolic dysfunction-associated steatotic liver disease, the new name for what used to be called non-alcoholic fatty liver — affects roughly one in four people globally. Dr. Asamoah stresses it’s ‘not a liver problem, it’s a metabolism problem,’ tied to the same metabolic syndrome cardiologists watch: high blood pressure, high triglycerides, insulin resistance, and waist circumference. It also runs through the gut-liver axis: dysbiosis can cause intestinal hyperpermeability (‘leaky gut’), letting microbial toxins like LPS travel via the portal vein to the liver, driving inflammation and lipid dysregulation. Dr. Druz connects this to the ‘dyslipidemic triad’ — high triglycerides, elevated ApoB/LDL, low HDL — and notes MASLD also raises liver-cancer risk. Protecting your liver and your heart involve the same steps. Always work with a qualified clinician on your situation.

What’s the best stool test for assessing the microbiome?

Dr. Asamoah distinguishes between limited and comprehensive testing. Many panels rely only on PCR (16S), which strategically samples perhaps 30 to 35 sequences in certain strains — useful, but an incomplete picture. For a true ‘bird’s-eye view,’ she recommends whole-genome, next-generation sequencing, which captures the full array of organisms present and is especially good at detecting bacteria (less complete for every yeast strain). From there, a metric like the Shannon Index gauges your microbiome’s diversity against what’s considered healthy. She cautions that ‘healthy’ is defined across populations by age and region, and is influenced by ancestry and diet, so results should be interpreted in context rather than against a single universal standard. This is general education; testing decisions should be made with a qualified clinician.

What are the first steps to protect my gut and liver?

Dr. Asamoah’s advice is to go back to foundational steps — and to start by removing, not adding. Her top toxins to cut: alcohol (which she likens to gasoline on the flame of a fatty liver, noting the WHO considers alcohol harmful at any dose), high-fructose corn syrup and soda (strongly linked to fatty liver, even in children), and ultra-processed factory foods. Her second emphasis is movement: even 30 to 45 minutes of moderate activity helps reverse metabolic dysfunction and fatty liver, ideally combining continuous moderate exercise, some high-intensity intervals, and resistance training. Dr. Druz adds an important caveat — don’t sacrifice Zone 2 aerobic training for resistance work, since Zone 2 maintains VO2 max and metabolic flexibility. On the gut side, emphasize fiber diversity (about 25–30 g/day for women, 35-plus for men) and polyphenol-rich foods. This is educational information, not a personalized prescription.

Show Notes & Resources

Guest: Dr. Vivian Asamoah, MD

Dr. Vivian Asamoah (‘Dr. V’) is a board-certified gastroenterologist, hepatologist, and nutrition specialist, and the founder and CEO of Houston Gastro Institute in Katy, Texas. She completed medical school at the University of Geneva and her internal medicine residency and her gastroenterology, hepatology, and nutrition fellowship at Johns Hopkins. A certified functional medicine physician and faculty member for the Institute for Functional Medicine, she blends advanced GI care with integrative, root-cause approaches — including a signature functional gut-health program — and speaks nationally and internationally.

Houston Gastro Institute (Dr. Vivian Asamoah): houstongastroinstitute.com

Resources Mentioned in This Episode

Houston Gastro Institute — Dr. Vivian Asamoah’s integrative gastroenterology, hepatology & nutrition practice, including her 12-week and 6-month signature functional gut program (houstongastroinstitute.com)
Whole-genome (next-generation) stool sequencing & the Shannon Index — for a comprehensive microbiome assessment (vs. limited 16S PCR panels)
AHA Science Advisory on hypertension and the gut microbiome — salt’s effect on Lactobacillus; HAMSAB resistant starch lowering systolic blood pressure (~6 mmHg)
Resistant starches & fiber — green plantains, cooked-and-cooled rice/potatoes; aim ~25–30 g/day fiber for women, ~35 g+ for men, from polyphenol-rich foods
FIB-4 score & FibroScan (elastography + CAP) — noninvasive ways to assess liver fat and fibrosis (don’t wait for liver enzymes to rise)
MASLD — metabolic dysfunction-associated steatotic liver disease (formerly non-alcoholic fatty liver / NASH); the renamed, root-cause framing
Remove the toxins — alcohol, high-fructose corn syrup/soda, ultra-processed foods; move more (Zone 2 + intervals + resistance training)
Integrative GI mentors/authors referenced — Dr. Gerard ‘Gerry’ Mullin and Dr. Robynne Chutkan
Holistic Heart University — on-demand courses and resources (use code OWNER20 for 20% off annual)
HeartWell Toolkits — at-home heart and brain health lab panels (use code TESTING10 for 10% off and free shipping)
For clinicians: Practice Power Hour coaching with Holistic Heart Centers (use code DOC10 for 10% off)

Holistic Heart Centers

holisticheartcenters.com
HeartWell.ai — AI-powered cardiovascular risk assessment
Address: 55 Bryant Avenue, Suite #6, Roslyn, NY 11576
Phone: 877-511-5166
YouTube: @reginadruzmd
Instagram: @dr.reginadruz
Podcast: Own Your Heart Health — available on Apple Podcasts, Spotify, and all major platforms

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