Extremes of Life: The Microbial Arc

IPA AdminUncategorized

Childhood has never been longer than it is today. Launching offspring into adulthood often continues into three decades of life; physical growth and mental development carry on.

It is surprising then that our microbiota may reach adulthood by age 2 or 3. Toddlers are climbing about with a set of microbes that will stay remarkably stable until they struggle to walk near the end of life.

European investigators have published a paper titled The human intestinal microbiome at extreme ages of life. Dietary intervention as a way to counteract alterations. In engaging style, the authors strive to summarize “the current knowledge on intestinal microbiota alterations at the extreme stages of life and tools for designing differentiated nutritional strategies by the use of probiotics, prebiotics and specific nutrients in order to restore a balanced microbiota and to improve immune and nutritional status.”

The microbiota are unstable in infancy and old age, suggesting that alterations in microbiota, whether through a negative such as antibiotics or a positive like fermented food consumption, may echo more loudly on health.


  • Vaginal delivery and breast fed are gold standard for microbiota against which alterations are judged. But now we know that microbes show up earlier: placenta, amniotic fluid, umbilical cord blood, and meconium  are all teeming with microbes. Breast fed babies have more bifidobacteria and fewer pathogens than those bottle fed.
  • Shortchanging a fetus or infant can have long-lasting effects on immunity and metabolism.
  • At 18 months or so, write the authors, enterotypes emerge.


Three types of enterotypes stand out. Interestingly, long-term diet rather than nationality, age, gender, or body mass index predicts it.


The immune system suffers in aging. A low grade inflammation often leads to autoimmune and chronic diseases. Could species diversity be involved? The elderly have fewer species of most bacteria which can make them more vulnerable to pathogens.

Strategies for change at both extremes of life are discussed. Breastfeeding solely for 6 months with partial breast milk for at least 2 years is advised by the World Health Organization.

Nutritional strategies for the elderly focus on strengthening the immune system and correcting deficits.

In closing, it is suggested that “these population groups may require specific and nutritionally adequate products able to satisfy their particular requirements. Such knowledge should now be integrated into the development of a new generation of highly adapted functional food products.”