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.
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 tract 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.
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.
“Postbiotics stimulate healthy gut microbiota and support immune function through the gut²`¹⁰`²².”
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.
Postbiotics have been shown to support a healthy gut microbiota²². 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.
- Postbiotics are naturally occuring beneficial bacteria that affect the gut microbiota when ingested
- Prebiotics are non-digestible oliosaccharides that pass intact to the lower part of the gut where they stimulate the growth or activity of beneficial bacteria
- Postbiotics are bioactive components produced by the beneficial bacteria (through a natural fermentation process), which have biologic activity in the gut
40 years of early life science
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IMPORTANT NOTICE: Breastfeeding is best for babies. Infant formula is suitable from birth when babies are not breastfed. Follow-on milk is only for babies over 6 months, as part of a mixed diet and should not be used as a breastmilk substitute before 6 months. We advise that all formula milks including the decision to start weaning should be made on the advice of a doctor, midwife, health visitor, public health nurse, dietitian, pharmacist or other professional responsible for maternal and child care. Foods for special medical purposes should only be used under medical supervision. May be suitable for use as the sole source of nutrition for infants from birth, and/or as part of a balanced diet from 6–12 months. Refer to label for details.