9 Gut health myths you need to stop believing Part 2
#Guthealth is everywhere these days (and for good reason, as it plays such a big role in our overall health). Unfortunately, along with it comes a flood of advice, tik tok trends, and myths. Some of it is well-meaning, but much of it is …questionable.
In Gut Health Myths: Part 2, we’re exploring more common myths and misconceptions about gut health, with the hope of helping you make smarter choices for your gut and health.
Myth 1: ‘Leaky gut’ is the main cause of poor health
The term #leakygut is very popular, especially on social media, but the term is not medically recognized. However, "increased gut permeability" is and has been linked to conditions like IBS, IBD (Crohn’s and colitis), celiac disease, and functional dyspepsia. Scientific research suggests ‘’leaky gut’’ is more likely a symptom than a cause of these conditions. Environmental factors, alcohol, certain medications (like NSAIDs and antibiotics), stress, and genetics may also contribute to increased gut permeability ¹ ².
Your intestinal lining is actually semipermeable and not tightly sealed, allowing nutrients to pass into your bloodstream while blocking harmful substances. When this barrier becomes "leaky," it is usually due to:
Tight junction dysfunction: The "zippers" that hold gut cells together weaken, making the barrier less effective.
Epithelial damage: Physical damage to the gut lining creates gaps in the barrier ⁴ ⁵.
How to protect your intestinal lining and support mucus production
The bacteria in your gut ferment dietary fiber into short-chain fatty acids like butyrate, which fuel your intestinal cells and help maintain a healthy mucus layer. Without enough fiber, gut bacteria can start consuming the mucus layer itself, thinning this protective barrier and increasing the risk of inflammatory bowel diseases⁶.
To support your gut health focus on:
Eat gut-friendly foods: Include plenty of fruits, vegetables, prebiotics, fermented foods, and whole grains to nourish beneficial gut bacteria.
Limit certain substances: Reduce highly refined foods, excess sugar, alcohol, and NSAIDs (non-steroidal anti-inflammatory drugs), as these can exacerbate intestinal damage.
Manage stress: Practice stress-reducing techniques to support your gut and overall health.
Improve sleep habits: Prioritize quality sleep to help maintain a healthy gut.
Consider supplements cautiously: Supplements like glutamine and zinc may help strengthen the gut lining, but consult a healthcare professional before using them ⁷ ⁸ ⁹ ¹⁰.
Key takeaway: While increased intestinal permeability ("leaky gut") is a real phenomenon and plays a role in various diseases, it is not the root cause of poor gut health. Instead, gut health is influenced by a complex interplay of factors, including the microbiome, immune system, diet, and genetics.
Myth 2: Only food impacts your gut microbiome
While diet plays a significant role in shaping your gut microbiome, it’s far from the only factor. Your gut health is influenced by a wide range of elements, including genetics, exposure to germs, having pets, medications like antibiotics, stress levels, sleep quality, exercise, pollution, and even how you were born (vaginal birth vs. C-section) or whether you were breastfed.
Geographical location also matters, as people in different regions have varying dominant gut bacteria¹¹ ¹² ¹³ ¹⁴.
Key takeaway: Gut health is a complex interplay of diet, lifestyle, environment, and genetics and is not impacted only by what you eat.
Myth 3: Fermented foods always contain probiotics
Not all fermented foods contain probiotics. Probiotics are specific microbes proven to provide health benefits, while many fermented foods will lack live microbes after processing.
Probiotics: Live microorganisms that confer health benefits when consumed in adequate amounts. They have specific strains and target specific conditions (e.g., diarrhea, IBS)¹⁶.
Fermented foods: Foods produced by microbial growth (e.g., yogurt, kefir, sauerkraut). Many have been consumed for centuries and offer potential health benefits ¹⁵.
Not all fermented foods contain probiotics:
Some fermentation processes kill the beneficial microbes (e.g., pasteurization, baking).
Not all microbes used in fermentation have proven health benefits or survive the gut.
Even if present, the amount of live microbes may not be sufficient for probiotic effects.
In simpler terms: You can't assume all fermented foods have probiotics just because they've been fermented.
Key takeaway: If you're looking for probiotics, check the label of the fermented food to see if it contains specific strains of live and active cultures.
Myth 4: Prebiotics and probiotics are the same thing.
Prebiotics and probiotics are not the same but ‘work together’ to support gut health. Probiotics are live beneficial microorganisms that improve health when consumed in adequate amounts, while prebiotics are non-digestible compounds that act as "food" for these beneficial bacteria, helping them grow and thrive ¹⁸.
For example, probiotics can be found in some fermented foods like yogurt or supplements, whereas prebiotics are found in high-fiber foods like garlic, bananas, and whole grains.
Additionally, there’s something called synbiotics, which combine both probiotics and prebiotics in one product to maximize gut health benefits ¹⁷.
Myth 5: Probiotics can fully restore your gut microbiota after taking antibiotics
Current evidence does not support the idea that probiotics can completely restore the gut microbiota to its pre-antibiotic state. While some probiotics may modestly reduce antibiotic-associated diarrhea their effects are limited and not universal (depending on factors like strain, dose, patient age, and the specific antibiotic used)¹⁹ ²⁰.
Restoring and supporting gut health after antibiotics
Will vary from person to person but a good good starting point for everyone is to focus on the fundamentals:
Diverse plant-based diet: Aim for at least 30 different plant-based foods weekly, including a wide variety of vegetables, fruits, nuts and seeds, beans, pulses and whole grains.
Fermented foods + probiotics: Incorporate these into your diet regularly.
Key takeaway: Probiotics can still be beneficial for managing antibiotic-related symptoms, like diarrhea, but they are not a one-size-fits-all solution for restoring the microbiome.
Myth 6: Gut Microbiota and Gut Microbiome are the same thing
While the terms are related, they refer to different concepts. The gut microbiota specifically describes the community of microorganisms (bacteria, fungi, viruses) living in the gut.
The gut microbiome, on the other hand, encompasses the entire ecosystem, including the microorganisms themselves, their genes, and the environment they inhabit within the gut²¹ ²².
Think of your gut as a forest: the microbiota are like the trees, animals, and insects, the living organisms, while the microbiome is the entire forest ecosystem, including the soil, air, water, and sunlight.
Key takeaway: Gut microbiota is the "community" of microbes, while the microbiome encompasses the microbes and their genes, functions, and the environment.
Myth 7: We know exactly what a healthy microbiota or microbiome looks like
Scientists do not yet have a clear, universal definition of what a "healthy" microbiota looks like. The composition of the gut microbiome varies greatly between individuals due to factors like genetics, geography, diet, environment, and lifestyle. And research suggests that functional capabilities (what the microbiome does) may be more important than specific microbial composition ²³ ²⁴ ²⁵.
Key takeaway: Defining a "healthy" microbiome is highly complex. This is due to individual variability, the dynamic and ever-changing nature of the gut microbiome, and the fact that its functionality often matters more than its specific microbial composition.
Myth 8: Apple cider vinegar (ACV) reduces gut inflammation or improves gut health
ACV is advertised to reduce gut inflammation, balance gut bacteria, and prevent harmful bacterial overgrowth. While this sounds appealing, especially with the rise of ‘natural’ remedies, the reality is more nuanced.
Looking at the research ACV seems to have some antibacterial properties (from tests carried out in test tubes) ²⁶, but it doesn’t have the ability to ‘heal’ gut inflammation or regulate gut bacteria.
However ACV does appear to have some benefits, such as helping to lower blood sugar levels and slightly reducing appetite²⁷ ²⁸. Some studies on mice suggest ACV may improve gut health by supporting beneficial bacteria like Akkermansia and aiding the immune system ²⁹. However, evidence of its direct impact on human gut health is non existent.
Myth 9: More fiber is always better for your health
While it’s true that fiber is essential for health, and most people don’t meet the recommended 25 to 30 grams per day, some individuals may struggle with consuming too much fiber. This is particularly true for those with conditions like IBS, IBD (Crohn’s disease and ulcerative colitis), or diverticulitis ³⁰.
Additionally eating too much fiber in one meal, rather than spreading it throughout the day, can lead to painful bloating. Similarly, introducing fiber too quickly into your diet, especially if you previously consumed very little, can cause abdominal discomfort. Gradual changes and balanced fiber intake are better than trying to introduce a big amount suddenly.
P.S. Looking for a sustainable approach to weight management, gut health, and overall wellness? As a registered nutritionist (ANutr) with a BSc in Human Nutrition, I’m here to help!
I look forward to helping you thrive!
M.
Curious to learn more about gut health? Check out other related articles on the blog for tips, myths, and science-backed insights:
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