Taking probiotics during pregnancy and breastfeeding 

Our gut contains many different types of bacteria, and this collection of bacteria is called the gut microbiome. From the moment we are born, the different types and amounts of bacteria are very important for our health, not only as babies but throughout our lives. This is because the composition of the microbiome early in life influences how our gut health and immune system develop, which is why our microbiome as babies has short- and long-term impacts on health.^{1, 2, 3}  

Many factors help to shape the baby’s microbiome, including the pregnant woman’s own microbiome, whether she took antibiotics during pregnancy, the mode of birth (cesarean or vaginal), and whether or not the baby is breastfed. When a woman takes probiotics during pregnancy and breastfeeding, there may be a positive effect on the type of bacteria that grow in the baby’s gut, potentially benefiting the baby’s immune system and helping to reduce their risk of allergic symptoms.^{4, 5, 6, 7, 8, 9} 

A woman’s microbiome during pregnancy influences the baby’s immune system

Our immune system begins forming when we are in the womb. It continues to develop and mature for the first 36 months of life.¹ How our immune system develops is linked to our microbiome; scientific research has highlighted how important the bacteria in our gut are for our immune system.²  

The gut microbiome during pregnancy and breastfeeding affects the baby’s immune health

Exactly how bacteria affect the development of the baby’s immune system is not entirely known, but there are two ways that are thought to be important:

• The woman’s microbiome sends messages to the baby’s microbiome through breast milk and the placenta.³
• During vaginal birth, bacteria are transferred from the woman’s microbiome to her baby, influencing how the baby’s microbiome develops. This is called seeding.¹¹

Let’s take a closer look at how these two natural processes affect the development of the baby’s microbiome and immune system.

1. Breast milk and the placenta help shape the baby’s microbiome

It is important that the woman’s microbiome is balanced during pregnancy because her own microbiome can affect the development of her baby’s microbiome. The woman’s microbiome naturally changes during her pregnancy, however, if external factors lead to additional changes, there can be an effect on the health of the baby.^{12, 13} For instance, if a pregnant woman experiences stress during pregnancy, it may affect her microbiome, and consequently, impact the baby’s microbiome.¹⁴

Taking probiotics may help balance the maternal microbiome. Studies have shown that a baby has a reduced risk of developing allergic symptoms when the woman takes probiotics. When women were given the Lactobacillus rhamnosus, LGG^® probiotic strain (hereafter referred to by used of the trademark LGG^®) during pregnancy and breastfeeding (or they gave their baby formula that had been supplemented with the LGG^® strain if they were not breastfeeding), their newborn babies had a 50% lower risk of eczema compared to the babies whose mothers were given a placebo.⁴ When the babies were 4,^{4, 5} and 7 years old,^{4, 6} this positive effect remained, demonstrating that the LGG^® probiotic had a long-term beneficial effect. Taking a combination of three probiotics (the LGG^®, Bifidobacterium animalis subsp. lactis, BB-12^®, and Lactobacillus acidophilus, LA-5^® strains) during pregnancy and breastfeeding has also been associated with a reduction in babies developing eczema.⁷

2. Vaginal delivery promotes beneficial bacteria in the babies’ gut microbiome

During vaginal birth, a baby’s microbiome may be directly influenced by the woman’s microbiome.  

Between trimesters 1 and 3, a woman’s gut microbiome changes dramatically, and involves an increase in the amount of the beneficial bifidobacteria.^{15, 16} Bifidobacteria are important in the early years of life because these bacteria are central to the development of a baby’s immune health.¹⁷  

In one study, the researchers followed 17 mothers and their infants. It was observed that in babies born by vaginal delivery, very specific strains of bifidobacteria were present in both the mother and baby.¹⁸ However, the babies who were born by cesarean did not have these specific strains in common with their mothers.¹⁸ This suggests that these specific bacteria were passed from the woman to her baby during vaginal birth.¹⁸  

In another study, babies born to women who consumed the LGG^® probiotic strain in the weeks before giving birth had more of the beneficial bifidobacteria in their gut.⁹   

Consider taking probiotics during pregnancy and breastfeeding as they may benefit the baby’s developing immune system

Results from clinical studies emphasize that pregnancy and breastfeeding provide important points of interaction between the pregnant and breastfeeding woman’s gut bacteria and her baby’s microbiome. The evidence discussed highlights that taking probiotics during pregnancy and breastfeeding may support the development of the baby’s immune system and help reduce their risk of allergic some skin conditions. 

  
LGG^®, BB-12^® and LA-5^® are registered trademarks of Chr. Hansen A/S.

The article is provided for informational purposes regarding probiotics and is not meant to suggest that any substance referenced in the article is intended to diagnose, cure, mitigate, treat, or prevent any disease.