The Ultimate Guide to Human Milk Oligosaccharides: Science-Backed Benefits for Gut Health — Dr Brad Leech (2024)

When it comes to gut health, we often think about probiotics - those friendly bacteria that help keep our digestive system balanced. But scientists have uncovered another critical component of breastmilk that is now gaining recognition for its role in establishing a healthy gut microbiome far beyond infancy.

They’re called human milk oligosaccharides (HMOs), and they’re complex sugars that are naturally abundant in breast milk. Researchers have found that HMOs act as prebiotics capable of preferentially feeding our good bacterial species and helping them flourish. The more we discover these remarkable substances, the more excited researchers become about their diverse benefits throughout our lives.

These sugars may sound small, but they have an outsized impact on strengthening our gut defences and keeping disease-causing microbes at bay. From promoting healthy digestion to optimising our immune function, HMOs offer a tantalising new option in our quest for lifelong wellness.

Science-Backed Uses of HMOs - Research Review

Studies reveal HMOs increase bifidobacteria and short-chain fatty acid levels in the gut. This makes HMOs a smart choice for cases of low bifidobacteria or SCFA production, which underlie dysbiosis.

Research confirms HMOs strengthen intestinal barrier integrity and reduce permeability. For “leaky gut” and heightened gut inflammation seen in conditions like autoimmunity, HMOs can help manage permeability.

In the presence of detected pathogens like Campylobacter jejuni, Clostridium difficile, Escherichia coli, Streptococcus pneumoniae, Salmonella and Helicobacter pylori, HMOs may help clear overgrowth by blocking adhesion to the intestine wall.

Given HMOs’ multifaceted gastrointestinal benefits and excellent safety profile, they are emerging as an effective treatment for irritable bowel syndrome in clinical practice.

The mechanisms of action of Human Milk Oligosaccharides (HMOs).

1. Prebiotic Function: HMOs act as prebiotics, fostering the growth of beneficial commensal bacteria in the gut. This fosters a healthy gut microbiota, which is crucial for overall digestive health and immune function.

2. Pathogen Binding: HMOs possess the capability to bind pathogens, preventing their attachment to the intestinal epithelium and subsequent infections. This action acts as a protective barrier against harmful microorganisms.

3. Enhancement of Epithelial Barrier: Through the production of Short-Chain Fatty Acids (SCFAs) during fermentation, HMOs contribute to the integrity of the epithelial barrier. This strengthens the physical barrier between the gut contents and the intestinal epithelium, reducing the risk of inflammatory responses.

4. Support for Mucus Production and Tight Junction Integrity: HMOs promote mucus production and maintain the integrity of epithelial tight junctions. This further fortifies the physical barrier within the gastrointestinal tract, preventing the entry of allergens and pathogens into the bloodstream.

5. Direct Immune Modulation: HMOs directly modulate immune responses, including the modulation of Dendritic Cells (DCs). This modulation plays a crucial role in shaping protective mucosal immune development, contributing to immune tolerance.

6. Systemic Immunomodulatory Role: A fraction of HMOs is transported across the intestinal epithelium, leading to systemic availability. This suggests an immunomodulatory role beyond the gastrointestinal tract, potentially enhancing tolerance induction and preventing allergic diseases.

HMOs in Clinical Practice: Real-World Observations

Now that we’ve explored the science behind HMOs, let’s discuss how this translates to real-world clinical use. As a practitioner, I’ve personally witnessed the benefits of HMOs for many patients - even those with sensitivities who struggle with other options.

For individuals with delicate constitutions prone to side effects, HMOs tend to be exceptionally well-tolerated. Their gentle action makes them unlikely to cause the uncomfortable bloating, gas, or diarrhoea some experience with prebiotic fibres.

For clients adhering to restricted diets due to food sensitivities, HMOs can provide welcome prebiotic support. Since HMOs are sugars, not proteins, they avoid provoking adverse reactions. Their ease of digestion offers prebiotic benefits without triggering symptoms.

I frequently recommend HMOs as part of gut repair protocols to heal leaky gut. By strengthening the intestinal barrier, reducing inflammation, and optimising microbiome balance, HMOs facilitate mending and regeneration of the gut lining.

Additionally, I advise HMOs for clients using antibiotics or antimicrobials that disrupt the gut flora. HMOs help counteract dysbiosis that often accompany these medications by spurring the growth of beneficial bacteria.

Based on my clinical experience, here are the HMO protocols I generally recommend:

For long-term gut-healing, I typically prescribe 600mg twice daily taken after meals. This provides a steady prebiotic supply to continually nourish beneficial species over months. A lower ongoing dose is unlikely to cause side effects and can be sustained safely long-term.

For short-term gut repair or immune boosting, I advise 1200mg twice daily with meals. The higher transient dose helps rapidly increase HMO levels to stimulate bifidobacteria and strengthen the gut barrier when needed quickly.

I view HMOs as a first-line therapy for gut issues because they are so well-tolerated while bringing multi-layered benefits. I generally introduce HMOs early on, while monitoring symptoms to gauge the optimal dose for each individual.

For gut-related concerns, I recommend giving HMOs 3-12 months to work have their benefits. It takes time to overhaul the intricate ecosystem in our guts and generate lasting improvements in barrier integrity. Patience and consistency are key!

The two HMO supplements I recommend to my patients are 2’-FL + Zinc Gut Repair and 2'-FL HMO ProBOOST Vit D

Of course, these are simply general guidelines based on my experience. Dose and duration should be tailored for your unique needs under a practitioner’s guidance.

Microbiome Testing and HMOs

Microbiome testing analyses the diversity and abundance of bacteria in your gut, providing valuable information about which species may be thriving or lacking. Armed with this knowledge, you can make informed decisions about whether HMO supplementation is right for you and how to optimise its effectiveness.

For instance, if your microbiome analysis reveals a deficiency in bifidobacteria species such as Bifidobacterium infantis or Bifidobacterium breve, which are known to thrive in the presence of HMOs, you may benefit significantly from supplementation. By selectively feeding these beneficial bacteria with HMOs, you can promote a healthier balance in your gut microbiota, potentially leading to improvements in digestion, immune function, and overall well-being.

Moreover, microbiome testing can identify specific pathogens or imbalances in your gut microbiota that may be contributing to gastrointestinal issues or inflammation. In such cases, targeted supplementation with HMOs can help mitigate these imbalances by promoting the growth of beneficial bacteria while inhibiting the proliferation of harmful pathogens.

By integrating microbiome testing into your approach to gut health, you gain valuable insights that enable you to harness the full potential of HMO supplementation. I use the MetaXplore GI Plus from Co-Biome by Microba to assess microbial markers, gastrointestinal health markers, and more.

Order your microbiome test

Summary

HMOs offer a promising natural tool to influence microbial communities in a targeted way, while also strengthening intestinal defences and immune function. The synergistic mechanisms make these human milk sugars uniquely suited to address dysbiosis and permeability underlying many chronic conditions.

The key is consistency. With regular daily doses, we allow time for microbial shifts to gradually occur. Patience provides the space for HMOs’ multi-layered mechanisms to transform our inner ecosystems. HMOs just may hold the key to gut health and lifelong wellness by starting from the ground up.

Dr Brad Leech

Brad is a PhD-qualified Clinical Nutritionist and Herbalist specialising in chronic autoimmune conditions and complex gastrointestinal disorders. He provides complete and personalised care to his patients using functional nutrition, integrative medicine and holistic wellness.