Why Do Vegans Still Get Bloating? Understanding SIBO and Plant-Based Gut Health

If you’ve been eating a plant-based diet for a while, you probably know the scenario: you’re doing everything “right.” Your meals are full of vegetables, beans, lentils, grains, and fruit. Yet instead of feeling light and energised, your stomach is tight, swollen, and uncomfortable. Sometimes the bloating is mild and passes, but for many people it’s persistent, painful, and makes them question whether vegan eating is really good for their digestion.

The truth? It’s not that plants are “bad for your gut.” Instead, bloating often signals that something deeper is going on in the digestive system. One of the most common underlying issues I see in vegan clients is SIBO (Small Intestinal Bacterial Overgrowth). Understanding how it works can explain why healthy food sometimes feels anything but.

Bloating on a Vegan Diet — What’s Normal and What’s Not

A little bloating after a very high-fibre meal can be normal, especially when you’re eating beans, cruciferous vegetables, or other fermentable foods. Fibre feeds your gut microbes, and a small amount of gas is simply part of the process. But if you’re finding that:

• Your stomach looks or feels distended every day

• You’re dealing with cramping, pain, or reflux

• Your digestion swings between constipation and diarrhoea

• You feel exhausted, foggy, or anxious alongside gut symptoms

…then it’s not “just bloating.” This pattern can indicate SIBO or another imbalance that needs to be addressed.

What Exactly Is SIBO?

SIBO stands for Small Intestinal Bacterial Overgrowth, and the name is fairly self-explanatory. Normally, most of your gut bacteria live in the large intestine, where they happily ferment fibre into beneficial compounds. But in SIBO, bacteria migrate upwards into the small intestine, where food is less fully digested.

Here, fibre and carbohydrates become easy fuel for bacteria in the wrong place, leading to fermentation, gas, and bloating. It’s why so many of the healthiest foods in a vegan diet — lentils, chickpeas, apples, garlic, broccoli — can suddenly feel like the enemy.

SIBO symptoms often overlap with IBS (Irritable Bowel Syndrome) and include:

• Bloating (the hallmark symptom)

• Abdominal pain and cramping

• Constipation, diarrhoea, or alternating between both

• Reflux or heartburn

• Nausea or a sense of fullness after small meals

In fact, SIBO is now commonly considered one of the leading drivers of IBS.

Why Vegans Notice It More

Plant-based diets are naturally high in fibre, which is wonderful when the digestive system is balanced. Fibre feeds the gut microbiome, supports bowel regularity, and lowers inflammation. But with SIBO, fibre ends up feeding bacteria in the wrong place. This explains why vegans often experience more severe bloating compared to omnivores with the same condition.

It’s important to stress: this doesn’t mean vegan diets cause SIBO. What it does mean is that a plant-rich diet can highlight underlying imbalances more clearly. If your gut isn’t functioning well — if stomach acid is low, if motility (the wave-like movements of the gut) is sluggish, or if stress is impacting your digestion — those abundant beans, grains, and vegetables can feel overwhelming.

Vegan Gut Health Myths

When people feel unwell on a vegan diet, they’re often told the diet itself is the problem. I’ve seen many clients advised to abandon vegan eating altogether when they report bloating or IBS-type symptoms.

But this isn’t the full story. The reality is:

• It’s not the plants, it’s the gut environment. If bacteria are in the wrong place, even the healthiest foods can cause problems.

• Symptoms are a message, not a verdict. Bloating and discomfort are signs that your body needs support, not that your diet is inherently wrong.

• Healing is possible. Once the root causes are addressed, most vegans are able to return to eating a wide variety of plant foods without distress.
  
  
  
  
  
  

Why Does SIBO Happen?

Several factors can set the stage for SIBO:

• Low stomach acid – without enough acid, food isn’t sterilised or digested properly, giving bacteria an opportunity to grow higher up.

• Sluggish motility – the small intestine relies on rhythmic muscle movements to sweep bacteria downwards. Stress, trauma, or certain conditions can slow this “clearing wave.”

• Food sitting too long – poor digestion or structural issues can allow fermentation to start earlier than it should.

• Stress – the nervous system and digestion are intimately linked. When we’re stressed, our gut motility slows, which increases the risk of bacterial overgrowth.
  
  

Supporting a Healthy Vegan Gut

The good news is that there are many strategies to support digestive health without giving up your values or your plant-rich diet. These include:

1. Adjusting Fibre Intake

• Rotate legumes rather than overloading on one type.

• Try soaking or sprouting beans and lentils to make them easier to digest.

• Work with a vegan healthcare practitioner who specialises in gut health, IBS and SIBO on a temporary vegan SIBO dietary plan if symptoms are severe.
  

2. Supporting Digestion

• Nutrients like zinc are essential for stomach acid and enzyme production.

• Bitter foods (rocket, dandelion greens) can gently stimulate digestion.

• Eating slowly and mindfully helps the body shift into “rest and digest” mode.
  
  

3. Herbal and Nutritional Approaches

• Certain herbal antimicrobials can reduce bacterial overgrowth in the small intestine.

• Probiotics may be helpful, though the right strain and timing are essential.

• Magnesium supports healthy motility and regular bowel function.
  
  

4. Nervous System Care

• Breathwork, meditation, or yoga can reduce the stress response that impairs digestion.

• Addressing unresolved trauma or chronic stress can transform gut symptoms at their root.  I love to use Family Constellations and Rapid Core Healing therapies to support these.
  
  

When to Seek Support

If bloating is persistent, painful, or accompanied by mood changes, nutrient deficiencies, or ongoing fatigue, it’s time to seek support. Testing such as breath tests can clarify whether SIBO is present, and a personalised plan can be created for healing.

As a naturopath who works extensively with vegan and plant-based clients, I know how important it is to have your health supported without being told to abandon your values. With the right strategies, you can restore balance to your gut, relieve bloating, and feel energised again — all while continuing to eat the foods that align with your ethics and lifestyle.

Conclusion

Bloating doesn’t mean you’re failing at being vegan. It’s a signal from your body that something deeper needs attention. By understanding the role of SIBO and other digestive imbalances, you can take the confusion out of why your gut feels so reactive and start moving towards real healing.

A healthy gut doesn’t mean cutting out plants — it means creating the conditions for your body to thrive on them.

By Camilla Brinkworth BHSc Naturopathy, Grad Cert Human Nutrition – Naturopath, Nutritionist & Vegan Health Specialist

As a naturopath and long-term vegan, I help people restore balance to their digestion without giving up the foods that align with their values. I specialise in supporting vegans and vegetarians with SIBO, IBS, and plant-based nutrition challenges through evidence-based naturopathy and compassionate care.