Gut from my mumma - maternal influences on baby's microbiome.

The field of research on the gut microbiome is one of the hottest topics right now. One of the most exciting findings is the influence of mum's diet and lifestyle on her own gut health, and how the conditions in utero, birth and breastfeeding become the foundations for baby’s health.

The building blocks of health – the first 1000 days

From conception up to your child’s second birthday is a key period determining baby’s lifelong health and disease risks. This is impacted by a myriad of factors like maternal diet and microbiome, delivery, maternal diet during breastfeeding and infant diet, as well as environmental exposures such as medications, stress.

Why a healthy microbiome means a healthier you and healthier baby

The spectrum of "health" has many interacting factors, and the gut microbiome is being linked to so many health conditions. Early life exposures that influence the make-up of the gut microbiome are now being linked to a wide range of health conditions, from pregnancy related conditions like gestational diabetes and pre-eclampsia, to baby’s health conditions, such as allergy responses like eczema and asthma, auto-immune conditions like type 1 diabetes and coeliac disease, and even long-term lifestyle conditions like obesity, cardiovascular disease and type 2 diabetes. There is also now strong evidence for the role the gut in many mental health disorders. All of these conditions have a common theme in some form of overactive and/or chronic inflammatory response which is either localised or systemic.

The research is currently speeding towards mapping exact bacterial strains and their specific genes that can be used to prevent or “treat" specific conditions. However, there is currently no standard definition of a healthy gut microbiome. What we do know are some key characteristics that can support good gut health based on microbial communities being:

  • highly diverse

  • stable

  • and resistant to stress-related change (antibiotics, infections, immunosuppression)

So, what is this microbiome?

In conversation, the words microbiome and microbiota are often referred to as the same thing. However, the distinction is that microbiota are the live bacteria and organisms that are in and on us, whilst the microbiome refers to the genes contained within the diverse population of these micro-organisms. When discussing gut health, we become more interested in the approximated 100 trillion bacteria within the human intestinal tract. The genes within these microbiota (aka the microbiome) are 150 times more than those of the human genome! Mind = blown.

The gut microbiota contributes to several vital functions which cannot be achieved solely by the human body. Some include:

  • processing of food to make energy available

  • synthesising B vitamins and vitamin K

  • synthesising essential amino acids

  • Supporting glucose and cholesterol metabolism

Furthermore, they also produce metabolites and signalling molecules such as short-chain fatty acids (like butyrate, acetate and propionate) which provide energy for the gut cells and colonic bacteria, and which also act as signalling molecules outside the gut. This is the pathway found to provide anti‑inflammatory effects. Hence why the gut, namely the gut-associated lymphoid tissue (GALT), represents almost 70% of our whole immune system.

Therefore, building baby’s digestive system and immune systems allows their health to be optimised to help them reach their full growth and developmental potential.

What you can do to boost your good little bugs

Diet - What goes in matters, as much as what doesn't.

We’ve all heard about probiotics - the useful bacteria – which can be found in fermented foods like yoghurt, sauerkraut, miso, pickles, tempeh and kimchi, to name a few. You may have even been advised to take a probiotic supplement after some medications and antibiotics, which can alter the balance of helpful bacteria. Once we’ve ingested these probiotics, however, the important step is to help them thrive by feeding them well! Otherwise ingesting the probiotics have little effect. This is achieved by including prebiotics (I know, how original), which are food substances that our bodies don’t digest, but are instead digested by the gut bacteria. These foods include fibre rich foods - but not all fibre is classed as prebiotic as only some remains undigested by our system and is instead digested by the gut bacteria to produce positive health effects. Some main prebiotic rich foods include:

  • fructans - grains like bran, couscous, muesli, pearly barley; nuts like cashews, pumpkin seeds, pistachios; fruit such as nectarine, white peach, pomegranate, persimmon, and vegetable sources such as artichokes, black beans, baked beans, brussel sprouts, silken tofu, garlic, onion, leek.

  • galacto-oligosaccharides - green peas, freekeh, butternut pumpkin, custard apple, lentils, and seaweed-derived products.

  • resistant starch (which are candidates showing promising results in animals, and still being studied further in humans. In the meantime, they taste pretty darn good) - these include rolled oats, green and unripe bananas, al-dente pasta, and rice and potatoes which have been cooked and cooled.

Source: Dietitian Connection

Additionally Breast milk transfers many complex prebiotics known as human milk oligosaccharides (HMOs), which make up around one-third of the composition of breast milk. These prebiotics have been shown to increase the abundance of beneficial Lactobacillus and Bifidobacterium which make up the majority of baby's gut flora.

Exercise - move, baby, move.

Physical activity prior to and during pregnancy has many positive effects on physical health, mental health, and birth outcome. Recent research is suggesting that exercise may able to enrich the gut's bacterial diversity. Specifically physical activity has been shown to improve the Bacteroidetes-Firmicutes ratio which support intestinal mucosal health and improve barrier functions. Other clues as to the benefit of physical activity on gut health includes the increased production of beneficial short-chain fatty acids such as butyrate. Further studies involving the human gut microbiome are needed, but this is another exciting space to watch!

Other lifestyle factors such as chronic stress, medications, environmental chemicals (such as pesticides and cleaning products) are all shown to impact the diversity and abundance of beneficial gut bacteria.

Future Directions 

Research is moving in the direction of reliable microbiome tests anytime from pre-conception to post-partum in the same way maternal blood and prenatal ultrasounds are utilised today. For example if a mother's microbiome profile reflects risk of conditions such as gestational diabetes, then medical direction towards a more balanced gut environment may be suggested using specific probiotics and foods. This may ensure a generational translation of beneficial gut bacteria which can in-turn promote a healthier life and population.

In the meantime, we can aim to follow lifestyle patterns associated with positive health for both mum and bub. Raising a child sure takes a community, and now we know that we can influence the micro-community to help start bub with their best foot forward.

For more reliable information see:

Food and Mood centre


How an expectant mum’s microbiome influences pregnancy and baby health

The Maternal Gut Microbiome during Pregnancy

Bacteria as vitamin suppliers to their host: a gut microbiota perspective

Modulation of microbiota as treatment for intestinal inflammatory disorders: An uptodate

Exercise Modifies the Gut Microbiota with Positive Health Effects

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