*Note: This article was originally published in 2018 and updated in 2025 to reflect current research.

DiverticuLOSIS happens when pouches form in the wall of the colon. If these pouches get inflamed or infected, it is called diverticuLITIS. The "itis" means "inflammation of" the diverticuli in the intestinal tract.

What Causes Diverticulitis?

Up until recently, medical professionals did not completely understand the cause of diverticulitis. It was once thought to be caused primarily as a result of a low-fiber diet that increased pressure in the colon (ie: strain & push harder) to move digested food through the bowel. It was thought that this increased pressure was what caused the small pouches in the intestines to form. 

Newer emerging research has revealed a more complex picture of the cause of diverticulitis. Today, functional medicine practitioners think the root cause of diverticulitis is linked to changes to the gut microbiome, biofilm formation, and chronic inflammation.

Imbalances in the gut microbiome play a central role in diverticulitis development. Specifically, diets low in diverse types of fiber may fail to nourish beneficial gut bacteria, such as Faecalibacterium and Bifidobacterium, which are known to produce anti-inflammatory compounds and help maintain gut lining integrity (1).

Without enough fiber in the diet:

• Good bacteria decline

• Gut microbial diversity shrinks

• Inflammatory and pathogenic bacteria can take over

• The intestinal lining becomes more susceptible to inflammation and infection

This microbial imbalance (called dysbiosis) can set the stage for flare-ups of diverticulitis, especially when paired with other factors like stress, medication use, or immune dysregulation.

Symptoms of Diverticulitis

Many people develop diverticula (the pouches in the colon) and never have symptoms, while others experience painful flare-ups (fever, chills, diarrhea, nausea, vomiting, and belly pain) which may be triggered by bacterial imbalances and immune system dysregulation.

The horrible and often painful symptoms are caused when food gets trapped in the pockets and the area becomes infected. There are specific strains of bacteria known to be associated with diverticulitis. Let's take a look at that research.

Gut Bacteria Linked to Diverticulitis

Emerging research suggests that bacterial imbalances in the gut microbiome play a key role in diverticulitis. Several studies have identified specific shifts in bacterial populations that may contribute to inflammation, infection, and flare-ups.

Studies now show that patients with diverticulitis often have:

• A decrease in Faecalibacterium prausnitzii
  This beneficial bacteria is known for its anti-inflammatory effects, primarily through its production of butyrate, a short-chain fatty acid that helps protect the intestinal lining. Lower levels of F. prausnitzii are commonly observed in people with active diverticulitis (2).

• A decrease in Bifidobacterium
  This beneficial bacteria is often depleted during inflammation or after antibiotic use. This crucial strain helps maintain gut barrier integrity and supports immune balance. Reduced Bifidobacterium levels are also seen in people with diverticular disease.

• A decrease in Proteobacteria
  This is a large group of bacteria, many opportunistic or pathogenic, and they're associated with inflammation. Examples of proteobacteria are Escherichia coli (E. Coli), Salmonella, Helicobacter, Klebsiella, Yersinia, and Vibrio (3). 

  In a healthy gut, Proteobacteria are present in very low numbers. However, when their population rises, it often signals that:

  • Beneficial bacteria have been depleted (ie: Faecalibacterium, Bifidobacterium)

  • The intestinal barrier is compromised

  • The person's gut is in a pro-inflammatory state

• An increase in Enterobacteriaceae
  A family within the Proteobacteria phylum, these bacteria are often found in higher numbers during intestinal inflammation and may contribute to flare-ups in diverticulitis (4).

• An increase in Clostridium species
  While some Clostridium species are beneficial, others are opportunistic pathogens. Elevated levels of pathogenic Clostridium have been noted in diverticulitis patients. In the presence of inflammation and infection, the number of good gut bacteria decreases and can no longer keep the C. difficile in check.  

• Biofilms in the colon
  Some studies have identified mucosal biofilms, which are communities of bacteria embedded in a protective matrix, in the colons of people with diverticulitis. These biofilms can trigger chronic immune activation and may make infections more difficult to resolve.

Manuka Honey and Diverticulitis

Manuka honey's antibacterial and anti-inflammatory properties are well-established in vitro and in animal models. Although there aren’t any clinical studies on manuka honey and diverticulitis, if we look at the research that exists on manuka honey and digestive disorders, we can draw the conclusion that manuka would be helpful to those who suffer from this condition.

Manuka has been reported to have an inhibitory effect on 60 species of bacteria, some species of fungi, and viruses (5). Therefore, it has the ability to limit bacteria growth and reduce the chances of an infection when food gets trapped in these pouches.

Manuka honey’s antibacterial agent, methylglyoxal, has been proven to work against a wide variety of pathogenic bacteria. In a study done in Wales, using Manuka 18+ provided evidence that manuka honey does exhibit bactericidal action against bacterial infection from C. difficile (7). The bacteria, C. difficile, is one of the most common bacterial infections to hospitalize people with gastrointestinal infections.

Manuka Honey and Gastrointestinal Infections

Oral administration of honey has also been found to protect against gastrointestinal infection through blocking the attachment of pathogenic microorganisms to the intestinal epithelium. This represents a potential strategy for disease prevention in the area of gastrointestinal infections, according to a study done in 2013.

Manuka Honey and Bifidobacterium

Manuka honey has also been found to increase and support the growth of Bifidobacteria via the presence of a variety of oligosaccharides (6). Bifidobacteria is one of the good gut bacteria that works to keep the gut healthy. Recent studies also suggest honey can inhibit inflammatory parameters caused by bacterial infections (5).

Is Manuka Honey a Root Cause Remedy?

While manuka honey is not a cure for diverticulitis, it may be a helpful tool in supporting gut health when used alongside other strategies like fiber-rich foods (as tolerated), probiotics, and targeted anti-inflammatory nutrients.

Purchasing Manuka Honey

But how do we know what or how much to take? This is a crucial aspect when using Manuka honey as an alternative treatment. The first step is to know where the manuka honey is from. Most studies have confirmed that manuka from New Zealand or Australia have higher antibacterial properties than honey from other countries.

UMF and MGO Ratings Explained

If you have been trying to assess the strength of Manuka Honey products, you may have noticed two different labels on the honey containers. One being UMF, the other MGO, which indicates high-grade activity. “Biologically Active” indicates a lower grade of activity.

UMF is an internationally registered trademark that can be used only by licensed users who meet set criteria, which include auditing and monitoring to ensure the product is natural, unadulterated Manuka honey that has the unique non-peroxide antibacterial activity and is true-to-label claim.

MGO ratings refer to the level of Methyglyoxal in the honey and is a trademark of Manuka Health New Zealand Ltd, and you will only see MGO labels on their own products.

Table of UMF and MGO comparison:

* MGO is measured as methylglyoxal mg/kg (ppm)

Manuka Honey Dosage

For use as an alternative treatment for intestinal infection and inflammation, 1 teaspoon twice a day of UMF 10-15+ should be used during flare-ups. This can be taken straight off the spoon or diluted in warm water. For day-to-day maintenance, a biologically active honey of 10-15 should suffice in most cases of diverticulitis. This can be used freely as it is the lower activity. Make sure your supplier is getting third-party testing on the honey’s activity and not just claiming its activity.

In Health and Happiness,

Kelly Harrington, MS, RDN

Registered Dietitian Nutritionist for Healthy Goods

References:

1. Reitano E, Francone E, Bona E, Follenzi A, Gentilli S. Gut Microbiota Association with Diverticular Disease Pathogenesis and Progression: A Systematic Review. Dig Dis Sci. 2023 Mar;68(3):913-921.  
2. Yarullina, D.; Pankratova, Y.; Karaseva, O.; Grigoryeva, T.; Karpukhin, O. Microbiota of the Colonic Diverticula in the Complicated Form of Diverticulitis: A Case Report. Life 2022, 12, 2129.

3. Shin, Na-Ri et al. Proteobacteria: microbial signature of dysbiosis in gut microbiota. Trends Biotechnol. Vol 33, Isesue 9, 496-503.

4. Tursi, A.; Papa, V.; Lopetuso, L.R.; Settanni, C.R.; Gasbarrini, A.; Papa, A. Microbiota Composition in Diverticular Disease: Implications for Therapy. Int. J. Mol. Sci. 2022, 23, 14799.

5. Hammond, EN & Donkor ES (2013, May 07). Antibacterial effect of Manuka honey on Clostridium difficile.
6. Eteraf-Oskouei, T. and Najafi, M. (2013, June). Traditional and Modern Uses of Natural Honey in Human Diseases: A Review.
7. Prakash A, Medhi B, Avti PK, Saikia UN, Pandhi P, & Khanduja KL. (2008, August 07). Effect of different doses of Manuka honey in experimentally induced inflammatory bowel disease in rats.