Infant Gut Bacteria Influenced by Diet and Birth


Infant gut bacteria

Credit: Bäckhed et al.

A common topic on this site is advances in how our microbiome affect and influence us, either changing our behavior or increasing the risk of certain diseases. Every week there seem like more progress are made in gut bacteria research, finding more puzzle pieces on how “good” bacteria influence our lives. This week a new study from Sweden looks at how C-section delivery and food during the first year affect infant gut bacteria types.

Our gut bacteria influence many things. Current researchers have found links between gut bacteria and obesity as well as changes in behavior and urges for certain types of food. Recent studies have even found that fast food can selectively kill off parts certain bacterial species increasing the craving for more fast food.

Infant Gut Bacteria Influenced by Food and Birth

Gut bacteria is not only linked to increased risk of diseases or craving. These good bacteria is also suspected to be a source of nutrient and vitamins for developing infants. But how does the gut microbiome form and which factors influence its make up? This is the questions investigated by a new study led by Fredrik Bäckhed from the University of Gothenburg in Sweden.

In the study Bäckhed and colleagues analyzed fecal samples from 98 Swedish infants and their mothers during their first year of life. The analysis revealed a connection between infant gut bacteria composition and the delivery method of the babies. Babies born by C-sections had smaller resemblance to their mother’s gut microbiome compared to babies delivered vaginally. In addition to how they were born, what type of food babies ate in the first 12 months also influenced the makeup of gut bacteria.

[pullquote]”Our findings surprisingly demonstrated that cessation of breastfeeding, rather than introduction of solid foods, is the major driver in the development of an adult-like microbiota,” says lead author Fredrik Bäckhed[/pullquote]

The study found that the earliest colonization of bacteria comes from the mother by contact during childbirth. After this first colonization occurs the types of bacteria changes depending on what the infant eats. When the baby stops eating breast milk the microbiome undergoes a shift toward the bacterial species more commonly seen in adults.


“The gut microbiota of children no longer breast-fed was enriched in species belonging to Clostridia that are prevalent in adults, such as Roseburia, Clostrium, and Anaerostipes. In contrast, Bifidobacterium and Lactobacillus still dominated the gut microbiota of breast-fed infants at 12 months.” – Bäckhed and Colleagues.

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