Chr. Hansen

Anders Damholt

The human microbiome is present almost everywhere on the human body and in fact, we humans are mostly microbes as the microbes outnumber our human cells ten to one. The majority live in our gut, particularly in the large intestine and play an integrated part of our well-being of the human. It is possible to modulate the human microbiome by supplementation of selected beneficial bacteria. Probiotics are live microorganisms, that possess health benefits when consumed in adequate amounts.

Many foods and supplements contain live microorganisms, but only those containing characterized strains with a scientifically demonstrated effect on health may correctly be termed "probiotics". These bacteria, which are selected based on a specific beneficial profile, isolated, and industrialized, can have significant and important effects on vital functions such as the immune system, digestive health and metabolism.  

Another way of modulating the microbiome is through supplementation with prebiotics. This concept is covers non-digestible carbohydrates, which are utilized by and selectively improve the growth of beneficial microbes in the gut.

By this definition, a probiotic strain as well as a prebiotic product, must be safe for the consumer and characterized by its specific identity, potency, and health benefits, features that must be proven by solid scientific evidence including clinical studies.

When co-administered, pre- and probiotics constitute a synbiotic. As a synbiotic, they may act in a complementary fashion, where both the pre- or probiotic confers a health benefit of their own, or synergistically where they work in tandem to support health benefits for the consumer.

From early infancy, the microbiome emerges through various sources and matures as we get older, and it is well established that the human microbiome changes throughout life. It is also now believed that the development of the human gut microbiome in early life has lasting effects and that unfortunate events in this process, such as antibiotic use, may affect health in adulthood. Gut microbial alterations during early infancy have been shown to affect the risk of childhood obesity, diabetes, asthma and allergic disease. The infant intestinal microbiome is initially – days after birth - relatively heterogeneous and populated by Proteobacteria, Clostridia, and Bacilli. However, early in life the intestinal microbiome becomes dominated by Bifidobacteria. This process is believed, in part, to be caused by the vaginal or fecal transfer of bacteria from mother to newborn during birth.

The habitation of the Bifidobacteria is further supported by feeding the infant with mothers’ milk, which contains Human Milk Oligosaccharides (HMO), a group of glycans, that is a source of nutrition for the microbiome. In particular, HMOs may modulate diversity, promote development of the immune system, reduce pathogenic infections and maturate brain development. The family of Bifidobacteria appear to have a specific pattern of using HMOs for growth, so as the composition of HMOs together with the environmental availability, can dictate the relative presences of these advantageous Bifidobacteria.

This complex universe had led to the development of the Bifido concept as an early-life critical window where the infant microbiome is most sensitive to environmental influences. 

The concept opens the opportunity of seeding the infant microbiome through supplementation of pre- and probiotics.

One way this can be facilitated is via oral supplementation to the pregnant mother prior to birth, wherein the beneficial bacteria can seed the infant microbiome through natural occurring fecal transmission from mother to infant However, a more comprehensive seeding can be achieved through oral delivery to the newborn baby.

Bifidobacterium longum subsp. infantis (B. infantis) is a member of the Bifidobacterium genus and is characterized by a specific pattern of utilizing HMOs, thereby promoting the presence of B. infantis in the intestinal microbiome. Thus, B. infantis represent a qualified candidate to supplement regular nutrition for both the expectant mother and newborn child.

Mothers of newborn infants are encouraged to breast feed, wherein mothers’ milk will help deliver HMOs l and promote growth of beneficial bacteria such as B. infantis in the newborn intestinal environment. This process can be further stimulated by the supplementation of specific HMOs to infant formula.

Compelling clinical evidence show that supplementation with B. infantis can modify the infant microbiome by enriching the relative abondance of the bifido species. This, in turn allows for identification of beneficial effects of the intervention.

Initially, within days and weeks, beneficial changes can be detected through validated questionnaires, including reductions in compulsive crying and improvements in stool frequency and consistency. These clinical effects may have a basis within metabolites secreted by the modified microbiome enriched in the bifido species, including short-chain fatty acids which may change pH of the faesis, as well as the balance of bile salts.

As a later response to a modified microbiome enriched in the bifido species, the immune system can mature, resulting in a lower incidence rate of infections leading to common cold or diarrhea. Furthermore, the risk of developing autoimmune complications later in life, such as atopic dermatitis, may also be reduced. Interaction with the infant immune system may include ligand activation of toll-like receptors on the immune cells. Additionally, ligands for the newly discovered aryl hydrocarbon receptor can be secreted from the enriched bifido bacteria.

The bifido concept, while known for years, is still poorly understood. However, the concept of supporting the infant to a healthy start in life, has been investigated thoroughly and emerging data will be revealed in the coming years. Going forward, the strengthening of infant health will have a massive impact not only for family quality of life, but also for the broader social economic, in the industrial and developing worlds.