A healthy gut microbiota composition is essential for optimal immune system development and function in infants and has the potential to lower the risk of disease in infancy and beyond3.
Increased understanding of the role of the gut microbiota in health has highlighted the benefits of pre- and probiotics, and now, postbiotics are emerging as a further source of support for the development of a strong and stable immune system. Produced by a natural fermentation process, postbiotics have been shown to benefit the adaptive and innate immune system and improve gut barrier function1,2. Pioneering research is examining the potential benefits of adding postbiotics to infant formula to support gut health and immunity.
Microbes and the gut microbiota
The human body is comprised of trillions of microbes (bacteria, viruses, fungi, etc) in addition to human cells. Estimates of the ratio of microbe to human cells have varied from 10:1, to more robust, recent research that suggests the split is much more of equal proportion4. The influence of these microbes on our health and body functions is far-reaching.
The digestive system is host to many of these microbes – the gut microbiota. Our digestive system could not function effectively without them. Bacteria in the gut are not only important for healthy digestion – they also play a vital role in metabolism, cognitive function and immunity5.
Early life gut health and immune system development
The first 1,000 days is a critical window when the gut and immune system develop rapidly, as babies move from a protected environment to one where they are exposed to lots of immune challenges3. The development of healthy gut microbiota is essential for immune system development and function3. Early nutrition is the main influence on initial microbiota composition; and optimal nutrition fine-tunes the immune system and sets up metabolic homeostasis in early life, influencing long-term health3,5. Breastmilk is the best possible source of nutrition for a healthy microbiota composition6,7. Recent research suggests around 30% of gut microbiota in breast-fed infants comes directly from their mother’s milk8.
As well as being an optimal source of beneficial bacteria, breastmilk contains prebiotic human milk oligosaccharides which positively shape the infants gut microbiota9. These prebiotics pass intact to the lower part of the infants’ gut where they are selectively fermented by beneficial bacteria such as bifidobacteria – allowing the amplification of these bacterial populations7,9. This fermentation process also creates postbiotics – bioactive components that play an important role in the regulation of biologic activity in the gut1,7.
Know your biotics
- Probiotics are naturally occurring beneficial bacteria that affect the gut microbiota when ingested10.
- Prebiotics are non-digestible oligosaccharides that pass intact to the lower part of the gut where they stimulate the growth or activity of beneficial bacteria11.
- Postbiotics are bioactive components produced by beneficial bacteria (through a natural fermentation process), which have biologic activity in the gut1,10,12.
The transformational power of fermentation
Fermentation occurs naturally in the gut, but people have also used fermentation as a method of food preservation throughout history. There are a huge variety of fermented foods in many cultures, which are consumed for both taste and health benefits. It is now recognised that many of the health benefits of fermented foods can be attributed to the postbiotics that fermentation produces13.
Fermented dairy products can improve gut health, increase infection-fighting antibodies and boost both humoral (immunity mediated by substances found in body fluids) and cell-mediated immunity13. Consumption of fermented dairy products has been shown to reduce the risk of several non-communicable diseases in adults14,15.
The immune-boosting power of postbiotics
A whole range of postbiotic bioactive components are produced during fermentation including short-chain fatty acids (SCFAs), enzymes, peptides (proteins), polysaccharides, cell surface proteins, and vitamins (see figure 1)12.
SCFAs are a source of energy for cells and help regulate energy homeostasis16. They possess antioxidative, anticarcinogenic and anti-inflammatory properties and play an essential role in the immune system17-21.
In babies that are not breast-fed, adding postbiotics to infant formula has been shown to result in a higher proportion of bifidobacteria in the gut microbiota population, creating a healthy microbiota composition closer to breast-fed babies22,23.
Regarding immune function, postbiotics have also been shown to improve the ability to fight infection by increasing the antibody response to pathogens22, as well as directly influencing gut barrier function1 and intestinal immunity24.
Pioneering infant nutrition – Feeding immunity through the gut
Nutricia has 40 years of research and innovation in infant nutrition and gut health, pioneering the use of LCPs (long chain polyunsaturated fatty acids, which contribute to normal brain and eye development), and was the first company to introduce a patented prebiotic mixture (scGOS/lcFOS (9:1)) into infant formula. Nutricia’s ongoing research is demonstrating the beneficial effects of formula containing a combination of pre- and postbiotics in supporting gut health and immune system development25,26.