Fermented Foods: Should You Be Eating Them?

Fermented foods, like kefir, kimchi and sauerkraut, are really coming to the fore for their potential health benefits. But is there substance to these claims or is it just hype? In actual fact, recent research underscores the profound impact these foods can have on our overall health, particularly through their influence on gut microbiota, metabolic functions, immune health and chronic disease management. I’ve looked at multiple studies over the past 5 years and have synthesized their findings to create a holistic view of the benefits of including fermented foods into your diet.

To attain their health benefits, kefir, kimchi and sauerkraut should all be lacto-fermented. Lactic acid fermentation is a biological process by which sugars such as glucose, fructose, and sucrose are converted into cellular energy and the metabolic byproduct lactate. This process occurs in the absence of oxygen (anaerobic conditions) and is carried out by Lactic Acid bacteria like Lactobacillus, Lactococcus, Leuconostoc, and Streptococcus.  It is these types of bacteria that have a beneficial impact on health.

Fermented Foods and Gut Health

Lacto-fermented foods are rich in probiotic bacteria. It is these bacteria that confer health benefits. They can significantly alter gut microbiota composition, promoting beneficial bacterial strains that enhance gut barrier function and modulate immune responses.

• Gut Microbiota Modulation: Fermented foods increase the diversity of gut microbiota, fostering a healthy balance of microbial species. This diversity is crucial for digestive health and the prevention of gastrointestinal diseases.
• Immune System Support: The bacteria in fermented foods help strengthen the intestinal barrier by enhancing the production of tight junction proteins that seal the spaces between epithelial cells. A stronger barrier prevents the translocation of harmful bacteria and toxins into the bloodstream, reducing systemic inflammation.

Metabolic Benefits

The consumption of fermented foods is associated with improved metabolic health, including better regulation of blood sugar levels and appetite regulation.

• Blood Sugar Regulation: Fermentation produces bioactive compounds like short-chain fatty acids (SCFAs), particularly butyrate. SCFAs can positively affect insulin sensitivity by influencing fat metabolism.
• Appetite Regulation: Studies also show that consumption of fermented dairy products can lead to significant changes in appetite-regulating hormones. Specifically, reduced levels of ghrelin (a hunger-stimulating hormone) and increased levels of leptin (a satiety-signaling hormone). These hormonal changes can be associated with improved satiety and reduced calorie intake.

Chronic Disease Prevention

Fermented foods play a role in the prevention and management of chronic diseases through their anti-inflammatory and antioxidant properties.

• Anti-Inflammatory Effects: The bacteria in fermented foods can modulate the activity of immune cells, such as macrophages, dendritic cells, and T-cells. They can promote the development of regulatory T-cells (Tregs), which help maintain immune tolerance and prevent excessive inflammation.
• Antioxidant Properties: Many fermented foods are rich in antioxidants, such as polyphenols, which protect cells from oxidative damage and reduce the risk of chronic diseases.

Mental Health and Cognitive Function

Emerging research suggests that fermented foods can also impact mental health through the gut-brain axis.

• Mood Regulation: Probiotics from fermented foods can influence neurotransmitter production, such as serotonin, which plays a critical role in mood regulation.
• Cognitive Function: Improvements in gut health by fermented foods are linked to better cognitive function and a lower risk of neurodegenerative diseases like Alzheimer’s.

As you can see, it is worth incorporating fermented foods into your diet given the myriads of health benefits.

Very important note:

High Fermentation Byproducts: Some fermented foods, especially those that are high in FODMAPs (Fermentable Oligo-, Di-, Mono-saccharides and Polyols), can potentially worsen symptoms for individuals with SIBO. High FODMAP foods can ferment in the small intestine and contribute to bloating and gas.

Histamine Content: Certain fermented foods are high in histamine, which can be problematic for individuals with histamine intolerance or SIBO. Histamine can exacerbate gut symptoms and discomfort.