As soon as we are born, the collection of bacteria that colonize and collaborate with our digestive system starts to develop and evolve. Many different dietary factors, including how long we are breastfed and what we eat when we switch to solid foods, affect this developing colony. The influence of our early dietary experiences persist through childhood and have effects on our metabolism, report a team of researchers in Europe and China.
Their study looked at the gut microbiomes of over 200 children, aged 6–9, involved in the Dutch KOALA cohort study, which is following children born between 2001 and 2003 in the Netherlands as they grow into adulthood (Microbiome 2019, DOI: 10.1186/s40168-018-0608-z).
Previous research has shown that breast feeding can influence a baby’s gut microbiome, but this new study shows that those effects can persist and can also lead to metabolic differences.
The team, which included researchers at Maastricht University in the Netherlands and BGI-Shenzhen in China, found they could split the children into different groups depending on the relative abundances of different bacteria in their gut microbiomes. The cohort study data also included information about the children’s diets over time. The researchers found that preschool diet and length of breastfeeding affected which group of gut bacteria the children had.
Breastfeeding for longer and higher amounts of plant-based foods after weaning were associated with gut microbiota with more Bacteroides or Prevotella strains, which produce carbohydrate-degrading enzymes that help break down and digest plant fiber. Children who were breastfed for a shorter time and whose diet had higher amounts of total fat and sugar had simpler gut microbiomes, which were enriched in Bifidobacterium strains that favor simple sugars over complex carbohydrates.
The study’s findings “could mean different things,” bioinformatician Sofia Forslund of the Max Delbrück Centre for Molecular Medicine cautions. Is it the properties of breast milk itself or does breast feeding act as a proxy for some other variable that influences microbiome composition? The work, she adds, is part of a larger discourse on this issue where more research could clarify further.