Low FODMAP and IBS Relief
Low FODMAP and IBS Relief:
The SIBO Connection
In recent years, digestive health research has shifted its focus toward the gut microbiome—the trillions of bacteria that live in our digestive tract and play a vital role in digestion, immunity, and overall wellbeing. One area that’s received increasing attention is Small Intestinal Bacterial Overgrowth (SIBO), and how it may be one of the leading causes behind Irritable Bowel Syndrome (IBS) symptoms.
Research suggests that many people diagnosed with IBS may actually have SIBO, where bacteria ferment food in the small intestine instead of the large intestine. This process produces excess gas, bloating, and discomfort, helping explain why IBS often flares after eating certain foods. Understanding this link is shifting IBS treatment away from symptom suppression and toward addressing the root cause.
What is SIBO?
SIBO occurs when bacteria that normally live in the large intestine migrate into the small intestine, or when populations of bacteria in the small intestine grow excessively. The small intestine isn’t designed to host large amounts of bacteria—it’s where nutrient absorption takes place. Too much bacterial fermentation here can lead to:
Bloating and abdominal distension
Gas (often excessive or foul-smelling)
Diarrhoea, constipation, or a mix of both
Food intolerances
Nutrient deficiencies (from malabsorption)
Research suggests that SIBO may be a key driver behind many IBS cases, explaining why IBS symptoms often flare after eating certain foods, especially fermentable carbohydrates.
The Low FODMAP Diet and IBS
One of the most widely recommended approaches for managing IBS symptoms is the low FODMAP diet.
FODMAPs are fermentable carbohydrates (such as fructose, lactose, fructans, galacto-oligosaccharides, and polyols) that can be poorly absorbed in the small intestine. When bacteria ferment these carbohydrates, they produce gas and draw water into the intestine, triggering IBS symptoms.
By restricting high-FODMAP foods such as onions, garlic, apples, wheat, beans, and certain dairy products, many people experience rapid relief from bloating, pain, and altered bowel habits.
The Problem With Staying Low FODMAP Long Term
While the low FODMAP diet is incredibly effective for short-term symptom management, it’s not designed as a permanent eating plan. Here’s why:
Reduced microbial diversity: Strictly limiting fermentable fibres can starve beneficial gut bacteria, leading to long-term imbalances.
Nutrient restrictions: Many high-FODMAP foods are rich in prebiotic fibres, antioxidants, and vitamins that support overall health.
The root cause remains: While it reduces symptoms, it doesn’t address the underlying SIBO itself.
It’s common to see clients who have been told to stay on a low FODMAP diet indefinitely, or who have tried to follow it for years. While this can reduce symptoms in the short term, it often leaves them stuck on a highly restrictive diet, still not feeling their best, and sometimes with a gut microbiome that is even more out of balance.
Because of this, the low FODMAP diet is best used in three structured stages:
Elimination (short term, usually 2–6 weeks): Temporarily remove high-FODMAP foods to calm symptoms.
Reintroduction: Systematically test individual FODMAP groups to identify which ones trigger issues.
Personalisation: Return to the most varied diet possible, only limiting foods that consistently cause symptoms.
This stepwise approach ensures relief from symptoms while protecting the diversity and strength of your gut microbiome long term.
Addressing the Root Cause
If SIBO is driving IBS symptoms, symptom management alone isn’t enough. Functional testing, herbal antimicrobial treatment, gut motility support, and lifestyle factors (like stress management and improving sleep) are often needed to fully resolve or reduce SIBO. Supporting long-term gut microbial diversity and resilience should be the end goal—not permanent restriction.
Working with a practitioner can also help identify and address the underlying triggers that allow SIBO to develop in the first place—such as low stomach acid, slowed motility, or repeated antibiotic use—so that true healing and long-term relief become possible.
Key Takeaway
The connection between SIBO and IBS highlights the importance of looking beyond symptom suppression to the root cause of digestive distress. The low FODMAP diet can be a powerful short-term tool to relieve symptoms and improve quality of life, but it should always be followed by careful reintroduction and a focus on restoring a healthy, diverse gut microbiome.
If you’ve been struggling with ongoing bloating, discomfort, or food sensitivities—and especially if you’ve been told to stay on a restrictive diet long term—it may be time to take a deeper look at what’s really happening in your gut. A personalised gut health assessment or consultation can help uncover the root cause, guide you through safe dietary changes, and create a tailored plan to restore balance and long-term wellbeing.
