The following is the second of a two-part blog taking a closer look at fermented foods, written by Felicia Tejo, a student dietitian joining Clasado Biosciences for hands-on work experience. Felicia is aiming to build a career in healthcare, with a particular interest in early-life nutrition and gastrointestinal health. Click here to read part 1.


During fermentation and the production of fermented foods, microorganisms process the food material to form metabolites. These metabolites are responsible for the characteristically sharp taste, flavour, and nutritional properties of fermented foods2. Historically, metabolite production in fermentation is desirable as it may exert antimicrobial properties to improve food safety3. Nowadays, metabolites produced in fermented foods are also speculated to be bioactive and may confer some health benefits. Despite the rise in popularity of fermented foods and increased health claims for their metabolites, there is very limited evidence on the health effects of fermented food metabolites. Short-chain fatty acids (SCFAs) are common metabolites produced in fermentation by lactic acid-producing bacteria. SCFAs from fermented food can be taken up by the body and may play essential roles in human metabolism and health.


Research suggests that SCFAs in the gut may have diverse benefits to physical health, including:

  • The management of metabolic health
  • Improving glucose tolerance
  • Appetite suppressant
  • Maintaining colonic mucosa integrity
  • Reducing lipogenesis
  • Cholesterol synthesis

However, these studies are done on endogenous SCFAs formed by gut microbiota in the colon. Currently, there is limited evidence on the benefits of exogenous SCFAs from fermented food, and it is unknown if they confer similar benefits to endogenous SCFAs4.

Nutrient availability

As we know, diet is a crucial component of health and wellbeing. Fermenting food is shown to increase the bioavailability of nutrients and bioactive compounds. As a result, fermentation can increase nutrient absorption through the reduction of antinutrients (e.g., phytic acid in cereals) and the modification of the food matrix3. During fermentation, microorganisms may degrade the food matrix (e.g., fibre), thus allowing nutrients to be released and increasing the availability of nutrients from food4.

Potential Health Concerns

Fermentation involves microorganisms that may carry potential health risks. Although fermentation may produce beneficial metabolites, some undesired microorganisms may produce potentially harmful metabolites. This often occurs when fermentation is not strictly monitored or performed in controlled conditions, such as in home fermentation5. For instance, some strains of filamentous fungi may produce mycotoxin. Without thorough selection and elimination of mycotoxin-producing strains, consumption of the end-product (e.g., koji, cheese) can cause mild to severe health effect 2. Additionally, without strict food safety protocols, pathogenic microorganisms may contaminate the fermentation end-products.

Commercially produced fermented foods are manufactured according to strict food safety regulations and thus are safe for consumption. However, customers need to understand and follow the food’s specific storage instructions to maintain the food quality and prevent potentially harmful microbial contamination. When recommending fermented foods, healthcare professionals can play a role in educating the patients in food safety, to be aware of potential contamination and pathogenic microbial growth that are harmful to health.



Regular consumption of fermented foods is often linked to good health and longevity, but the exact reason behind this phenomenon is still unclear. The health benefits are often linked to the microorganisms present (may act as a probiotic), and the prebiotic, which if present, may help to support the immune system and gut microbiota. Additionally, the bioactive metabolites formed through fermentation may also contribute to health and wellbeing. To prevent misinformation for the public, further research is needed to identify the substances in fermented foods that benefit health. This information will also allow healthcare professionals to provide a more informed recommendation on fermented foods for optimal health outcomes, and potentially inform regulators on the incorporation of fermented foods into the dietary guidelines. To facilitate this, more research in the probiotic, prebiotic and metabolites of fermented foods is required to promote a food-first approach to health.

Our Products

Our latest blog posts

For Healthcare Professionals

View all

More for Healthcare Professionals


This section is an information and educational resource for healthcare professionals. It is not intended for consumers. If you wish to purchase Bimuno please click here