Citrobacter is a common bacterial infection. It is often seen when functional gut testing is done to get to the bottom of your digestive symptoms. This article will cover how and why Citrobacter infections may be contributing to your poor digestive health and will point you in the direction of natural treatment options for this particular bacterial overgrowth.
First off let’s outline some key concepts.
Citrobacter species, including the notable Citrobacter freundii, is generally regarded as being a commensal bacteria found in a healthy human gut. It only becomes a ‘problem’ when it is given the space and nutrients to grow (1).
In straight talk – Citrobacter is a bacterium that is a normal part of our gut flora. When given space to grow it can become a problem.
Citrobacter is a member of the Proteobacteria phylum and maybe more importantly the Enterobacteriaceae family. We have covered this family in depth in a previous article that I will be pointing you to a number of times in this article. If you haven’t read it yet, maybe this is a good time to hop over there and catch up to speed – How to treat bacterial infections: A holistic approach.
While the Proteobacteria phylum is represented in a healthy gut it all comes down to numbers. When allowed to grow the members of this grouping of bacteria can cause a range of issues as seen in the image below. A classic example of dysbiosis – or an imbalanced gut microbiota.
Other members of the Enterobacteriaceae family of bacteria include
- Escherichia coli
The headline from the family of bacteria that Citrobacter falls into is their negative impact on the immune system.
Let me explain.
Gram negative bacteria have a product known as lipopolysaccharide found in their cell wall. Lipopolysaccharide, also known as LPS or endotoxin, is released when the bacterial cell is disrupted. This in turn sets off an immune reaction and the inflammatory cascade associated with all of those nasty digestive symptoms that you may be experiencing (2).
Symptoms of Citrobacter infection
Citrobacter doesn’t always play nice. It has been associated with a whole range of different disease states throughout the body, and while these are less common, it is worth knowing.
- Urinary tract infections (more commonly associated with E. coli
- Respiratory tract infections
- Central nervous system infections
- Infectious arthritis
- Sepsis (bloodstream infections).
While these complications from a Citrobacter infection are very rare in healthy adults they are more common in immunocompromised individuals and in infants (3).
In immunocompetent adults (here the immune system is functioning properly) Citrobacter infections generally stay within the gut – either the small bowel or the large bowel. I like to look at this presentation as more of a bacterial overgrowth.
While Citrobacter can play a role in small intestinal bacterial overgrowth (4), you won’t be able to determine this with the stool testing listed below. Here you will need to rely on SIBO breath testing.
Stool tests will help to determine if you have a Citrobacter infection in the large bowel.
So which stool tests are best?
How Do I Test For a Citrobacter Infection and Overgrowth?
Due to the fact that you are reading this article I am assuming that you have already tested and found a Citrobacter infection.
Maybe you ran the comprehensive GI MAP (also known as Complete Microbiome Mapping here in Australia) as seen in the image below.
A second way to test for Citrobacter infections would be another DNA based stool test that gives you a more complete snapshot of the large bowel gut biome. These include Ubiome and Microba. Here you may have to dig a bit deeper into the results and possibly even download the raw data to see if you have a Citrobacter overgrowth. This is why it is important to work with a gut savvy clinician. In the long run it saves time and money.
Another stool test that may shown a Citrobacter infection is the comprehensive digestive stool analysis (CDSA for short). These culture and microscopy tests are far less reliable and are considered outdated technology by many digestive health experts. There are so many reasons why this is the case.
- Number one your stool sample is shipped to the lab, which may take days to weeks. The temperature variation could lead to shifts in the microbial population in the sample.
- Secondly the lab technicians actually have to grow the culture out. Here they use culture specific media that the bacteria enjoy growing on. Talk about skewed results!
- Finally most CDSAs give you a rating indicating the extent of the bacteria’s growth. Unlike the GI MAP (seen above) this is completely subjective. What is the difference between + and +++? Who knows! And how does this factor into you and your possible bacterial overgrowth?
Ok, enough culture and microscopy (CDSA) bashing. Let’s move on to how you may have contracted this particular infection.
Causes of Citrobacter infections
So we have established that Citrobacter is a normal inhabitant of a healthy gut. It only becomes a problem when it is allowed to overgrow and becomes a proper bacterial overgrowth in the large bowel. But how does this process actually happen?
The ongoing debate…
Here are a few theories backed up by science.
Some researchers point to inflammation driving the overgrowth of the family of bacteria that Citrobacter falls into. They postulate that, in the presence of inflammation, less friendly facultative anaerobic bacteria (such as Citrobacter) have a competitive advantage over the obligate anaerobic bacteria (most of the beneficial bugs) in the large bowel (5).
Seeing that an expansion of the members from Proteobacteria phylum (seen in the image above) such as Citrobacter leads to systemic inflammation this quickly turns into a vicious cycle. Inflammation feeds the growth of Citrobacter which then feeds inflammation…
Lost Bacterial Balance
As with most things in nature it all comes down to balance.
When some of the superstars of the gut have been compromised, or even lost, then this opens up a niche for less friendly bugs to move in.
You all know the major insults to your gut flora but let’s cover them just to be thorough.
- Antibiotics – We all know that antibiotics can really mess up our guts. Some of you may even have first hand experience with this. The real microbiome nerds out there may have even sampled their gut microbiome and seen low bacterial diversity (a major player in health and disease). To save us covering the same subject ad nauseum I will point you here for a deeper dive into the issues surrounding antibiotic use and how they actually lead to dysbiosis and bacterial infections! Funny that…antibiotics, often used to combat bacterial infections cause bacterial overgrowths that then lead to bacterial infections.
- Caesarean birth – When babies are vaginally born they inherit their microbiome from their mother. This passing of beneficial microbes from mother to child has been happening for much of our evolution. When c-sections are born they inherit much of their gut microbiome from the skin of their mother. The microbes involved in this bacterial hand-off are completely different and may contribute to an imbalanced gut.
- Baby formula – Formula fed infants miss out on so much goodness so much so that one scientific paper went on record saying that ‘breast milk is the perfect nutrition for infants, a result of millions of years of evolution.’ The same paper noted that mother’s milk contains prebiotics known as human milk oligosaccharides, perfect for feeding up beneficial bacteria in the newborn.
Treating Citrobacter Infections
A doctor will tell you to take antibiotics.
A naturopath, functional medicine practitioner or holistic doctor might tell you to take grapefruit seed extract or oregano oil.
Many times this kill focused approach may clear up your bacterial infection in the short term. In the long term this approach may leave you with a disrupted gut microbiome aka dysbiosis – the very thing you were given these heavy hitting treatments in the first place.
This may seem confusing and contradictory. How can a treatment that disrupts or damages your microbiota make you feel better?
It is complicated.
Again we circle back to the idea of balance vs imbalance. Bacterial overgrowths represent an imbalance in the gut flora. Treating these imbalances with extremely strong antibiotic-like antimicrobial herbs (oregano oil, grapefruit seed extract, high dose berberine long term) may kill off or reduce the bacterial overgrowths. Simultaneously, it may also negatively impact the beneficial gut flora that help to maintain the balance in your gut.
This concept was presented in a paper from a microbiome researcher Martin J. Blaser as the disappearing microbiota hypothesis. As our indigenous gut flora diminish over generations different diseases become more common. As we continue to loose our ancestral gut microbes allergies and metabolic diseases are becoming more common. Are they connected? Possibly.
The graph below outlines the loss of our ancestral microbiota over the past 80 years.
A more considered approach would be to look at the whole gut composition. The more that I have studied the gut microbiome the more that I look at it as a complex and fragile ecosystem. This ecosystem can be modulating by selectively feeding beneficial microbes with prebiotics and very select and targeted probiotics.
Many times this will help to reduce bacterial overgrowths such as Citrobacter to healthy levels in the gut.
If digestive symptoms don’t improve then certain herbal antimicrobials may be indicated. Here we can start with herbs that are less damaging to the beneficial bacteria in our gut and move towards stronger herbs as needed.
A microbiota centric approach
As always it takes a skilled gut clinician to assess and determine which course is best for you and your digestive symptoms.
Take it from me.
It took me five years plus to treat my gut imbalances. I was learning as I went and spent more money and time than I should have as I tried to get to the bottom of my digestive issues. In the end it took working with a gut savvy clinician to really help shift the needle.
From this journey I have been piecing together the best (and least harmful) approach to treating gut infections such as Blastocystis hominis (which may or may not need to be treated in each specific case), bacterial overgrowths in the small intestine and the large intestine.
If you would like to work with me please head over here. As of December 2019 I am offering free 15 minute consultations which are designed to see if we are a good fit and whether I think that I can help you.
As always please feel free to leave a comment and share your thoughts on your experiences with digestive health, prebiotics, probiotics and herbal medicine in the comment section below.
References and Resources
- The clonal relationship among the Citrobacter freundii isolated from the main hospital in Kermanshah, west of Iran
- Infections due to Citrobacter and Enterobacter
- Citrobacter Species
- Small intestinal bacterial overgrowth is associated with irritable bowel syndrome and is independent of proton pump inhibitor usage
- Why related bacterial species bloom simultaneously in the gut: principles underlying the ‘Like will to like’ concept
- Mother’s Milk: A Purposeful Contribution to the Development of the Infant Microbiota and Immunity.
- What are the consequences of the disappearing human microbiota?