One of the best gifts a mother can give her newborn is a balanced, healthy and diverse gut microbiota, and the most efficient way to achieve that is through diet during pregnancy.

A study published in Gut Microbes concludes that what mothers eat while pregnant shapes their gut microbiota composition. That, in turn, has an effect on the composition of their babies’ gut microbial community and on infant growth during the first 18 months of life.

It has been shown that the first 1,000 days of life are a crucial and a sensitive period in a baby’s life, when the foundations for short and long-term health are laid. In this critical period, gut microbiota plays a key role.

A growing body of evidence shows that diet is one of the most powerful factors driving the gut microbiota

During pregnancy, in birth and later in breastfeeding, mothers pass on gut microbiota to their infants, which firstly start to colonize the babies’ guts and then contribute to the more diversification of the gut microbiota. When that early colonization is disturbed, there is an increased risk of developing a range of conditions later in life, including obesity, allergies and cardiovascular diseases.

A growing body of evidence shows that diet is one of the most powerful factors driving the gut microbiota. This is why maternal nutrition during pregnancy is believed to be crucial to supporting mothers’ health while also promoting adequate infant growth and development.

In this study, the researchers studied 86 mother-baby pairs, collecting data during pregnancy and monitoring the babies over a period of 18 months. Scientists used sequencing technologies to analyze fecal samples from mothers and babies at the time of delivery and obtained different gut microbiota profiles. They established a first group in which they included all women whose diet was based on a high amount of dietary fiber, omega-3 fatty acids and polyphenols. And a second group in which they included mothers with a significantly higher intake of carbohydrates, saturated fatty acids and animal protein.

Researchers have found a greater presence of Ruminococcus, a type of bacteria that produce butyrate, in women who eat a diet high in fiber and other nutrients. Butyrate is a biomarker of gut health and is associated with anti-inflammatory properties. On the other hand, women whose diet is mainly composed of carbohydrates, saturated fatty acids and animal proteins, showed a greater presence of Prevotella, an oral bacteria linked to an increased risk of disease and complications in pregnancy. Moreover, and importantly, the researchers saw that infants from mothers in the last group had a higher risk of becoming overweight in the first 18 months.

“We monitored the babies in the different groups for 18 months, following the guidelines dictated by the World Health Organization for longitudinal body mass index” explains María Carmen Collado, researcher at the Institute of Agrochemistry and Food Technology (IATA) of the Spanish National Research Council (CSIC). According to Collado, they observed differences between the two groups, which show mother’s diet can affect infant’s gut microbiota and thus, as it has been previously demonstrated, influence early life and adult health.

“In particular, fiber, vegetable protein and omega-3 acids [in maternal diet] have a significant effect on the baby’s microbiome and contribute to child development and a child’s health during the first months of life,” she adds.

According to the authors, their results are the first step in designing dietary strategies targeted at improving a mother’s microbial composition, and consequently a newborn’s gut microbiota, thus affecting the latter’s health status in the future.



García-Mantrana I., Selma-Royo M., Gonzalez S., et al. Distinct maternal microbiota clusters are associated with diet during pregnancy: Impact on neonatal microbiota and infant growth during the first 18 months of life. Gut Microbes.