LIBO: Large Intestinal Bacterial Overgrowth Explained
Large Intestinal Bacterial Overgrowth (LIBO)
A comprehensive guide to diagnosis and treatment. This article explains what LIBO is, the differences from SIBO, and the methods used in diagnosing and treating this lesser-known condition.
When we talk about gut dysbiosis and bacterial overgrowth, most people think about IBS (Irritable Bowel Syndrome) or Small Intestinal Bacterial Overgrowth (SIBO). However, there’s another condition — Large Intestinal Bacterial Overgrowth (LIBO) — that’s increasingly discussed among clinicians and integrative practitioners.
While the large intestine (also known as the colon) normally contains trillions of bacteria that support health, imbalance in this ecosystem can contribute to uncomfortable symptoms such as bloating, gas, diarrhea, constipation, mucus, and abdominal discomfort. These symptoms can overlap with SIBO and other forms of dysbiosis, and understanding the difference is key for proper care.
What Is LIBO? Understanding Large Intestinal Dysbiosis
The term Large Intestinal Bacterial Overgrowth (LIBO) has been circulating in the scientific community and spoken about in medical conferences, and is slowly starting to find its place in medical literature.
LIBO involves disruptions to the gut microbiota and an unusual proliferation of opportunistic bacteria within the large intestine. It is different from SIBO in the fact that the colon is meant to host a vast number of microbes within its walls, however this does not mean that the balance is always maintained.
LIBO thus refers to imbalance or overrepresentation of certain bacteria in the large intestine (colon) beyond healthy thresholds. Unfortunately, we now frequently see imbalances in the microbiota, namely due to poor dietary habits, liberal use of broad-spectrum antibiotics, as well as pesticides and herbicides in our food supplies. Let’s look into these factors.
Common Factors That Can Contribute to LIBO
Diet and Gut Microbiota Composition
Researchers explored whether diet alone, not just infections, could upset the delicate balance of gut microbiota. Their study on mice revealed significant changes in body weight (gain) and inflammatory markers associated with a high-fat Western diet rich in omega-6 fatty acids.
Negative changes in microbiota composition were observed, showing the potential impact of dietary choices, especially now that we are bombarded with ultra-processed convenience foods.
Antibiotics and Environmental Exposures
Another important cause: antibiotic therapy emerged as a pivotal factor in inducing dysbiosis. Broad-spectrum antibiotics, administered orally, significantly altered microbiota composition, reducing diversity and favouring certain bacterial phyla which are less optimal.
While the microbiome can usually recover post-treatment, complete restoration to pre-antibiotics levels proves challenging, hinting at the long-lasting impacts of antibiotic interventions.
Research results have demonstrated that there are still persistent long term impacts on the human intestinal microbiota that remain for up to 2 years post-treatment (this is how long the study was done for, so it could actually be longer than this).
Now, pesticides and herbicides present in our food and water do have antibiotic effects in the body, and if we’re not being cautious, we are basically microdosing antibiotics everyday through our diets alone. This is why I often recommend buying organic whenever possible, especially for The Dirty Dozen list from the EWG.
Lifestyle Factors
Last but not least, stress, poor sleep, and a sedentary lifestyle can affect gut motility and microbial balance, contributing to symptoms associated with colon dysbiosis.
LIBO vs SIBO — Key Differences
There are a few subtle differences between LIBO and SIBO.
Location:
SIBO is characterized by an excess of bacteria specifically in the small intestine.
LIBO is marked by an increased bacterial presence of opportunistic bacteria in the large intestine (colon).
Normal Microbiota Context:
In SIBO, bacterial load is too high where it should be relatively low.
In LIBO, the types and balance of bacteria matter more than raw numbers, since the colon is naturally bacterial-rich.
Symptoms:
This is where it gets tricky, because symptoms of LIBO and SIBO overlap heavily — including bloating, gas, pain, diarrhea, and constipation — making symptom-based distinction challenging or impossible.
Underlying Causes:
SIBO: Often linked to slowed small intestine motility, anatomical issues, surgeries, or immune dysfunction.
LIBO: Often linked to microbiome imbalance due to antibiotics, diet, metabolic influences, and other colon disruptors (such as surgeries).
Keep in mind that SIBO and LIBO can occur simultaneously. One does not necessarily indicate the other, however they are very closely connected.
Note: If your SIBO Breath test comes back negative within the first 100 minutes, and you still experience lots of symptoms such as diahrrea, constipation, bloating and gas, it could possibly be due to LIBO.
Diagnosing LIBO
There is no standardized diagnostic test for LIBO in mainstream medicine the same way there is for SIBO (with the SIBO breath test). However, practitioners use a combination of:
Stool microbiome testing (like GI-MAP) to assess microbial balance and identify dysbiotic signatures
Clinical symptom evaluation
Rule-out of other conditions such as IBS, IBD, SIBO, or food intolerances
A notable clue some practitioners use is a late rise in methane or hydrogen on SIBO breath testing (after 120 minutes), which may suggest back-pressure or fermentation patterns that originate in the colon rather than the small intestine — although this is not a definitive diagnostic criterion on its own.
It takes a knowledgable practitioner to understand the link between the symptoms and the microbiota presentation on the test results. It is not always required to eradicate or “kill” certain strains, sometimes a milder approach focusing on building a stronger community is enough.
How to Support Large Intestinal Microbiota Balance
Addressing LIBO requires a customized approach that can involve therapeutic interventions and lifestyle adjustments aimed at restoring balance to the large intestine's bacterial environment.
Each microbiome is different and what is required for one could be totally useless to another.
This is why one-size-fits-all protocols don’t work. It is important to know that shifting the microbiome takes time - we’re talking months, sometimes years depending on how long the imbalances have been brewing.
Here are a few aspects to look into while addressing LIBO:
Probiotics:
Incorporate targeted probiotic strains to rebalance the large intestinal microbiota.
Dietary Adjustments:
Modify the diet to support a healthy bacterial environment, emphasizing prebiotic-rich foods and reducing saturated fats. Lowering your consumption of Omega 6’s in favor of Omega 3’s can also reduce inflammation and positively impact the microbiome over time.
Some supplements, such as Butyrate, might also be temporarily helpful in bridging the gap while the growth of beneficial butyrate-producing bacteria (Roseburia, F. Prausnitzii) is being promoted trough diet.
Lifestyle Modifications:
Integrate stress management and vagus nerve toning techniques as well as regular physical activity to promote overall gut health. This is unsexy work, but stress and sleep do impact gut function tremendously. If your sleep sucks is poor, start there.
Antibiotics or Antimicrobials (when necessary):
This is always the last resort when it comes to addressing LIBO. I do believe that the environment of the large intestine can be rebalanced with the use of appropriate dietary and probiotic interventions.
If necessary, employ targeted herbals or selected antibiotic therapy to address specific pathogenic bacterial imbalances.
A note on Rixafimin: this antibiotic is commonly used in the treatment of SIBO, as it is effective in the small intestine only and is not systemic. The reason for this is that it needs bile to get activated, and it is an advantage in the case of SIBO treatment. However, since most bile acids are reabsorbed within the last part of the small intestine, it is reported to be deactivated once it reaches the colon, hence being ineffective for treating dysbiosis in the large intestine.
As LIBO's significance and dysbiosis gains traction, recognizing the dietary influences and the aftermath of antibiotic therapy becomes essential. These insights pave the way for milder, non-pharmacological interventions, emphasizing the need for a holistic understanding of gut health and its complexities.
For individuals suspecting LIBO, seeking guidance from a Gut Health Practitioner ensures a personalized evaluation and a targeted roadmap to lasting gut health.
🧡 Found this information useful? You can buy me a coffee / leave me a tip to support my work. 🧡