During gestation and lactation not only do the nutritional requirements of the mother increase drastically from her maintenance requirements, but providing quality nutrition is even more important not only to support the mother’s health, but also provide the best possible nutrition to the puppies, supporting their lifelong health.

The Puppy Microbiome at birth

It was thought in the past, that a foetus was sterile, and that the gut microbiome was populated after birth, through exposure to bacteria during birth, drinking colostrum, and the environment. This was known as the sterile womb paradigm. This is now under question, as studies found the foetus at full term already contains gut bacteria. Puppies born via caesarean section and traditionally (vaginally), also harboured the same maternal bacteria. If the microbiome bacteria were transferred during birth, we’d expect these to differ. Research is ongoing to understand the way in which bacteria enters the foetus. Although placenta structures do vary across different mammalian species, the placenta is a barrier to bacteria to protect the foetus from microbial pathogens.

A new hypothesis based on these recent findings, the womb colonization hypothesis, is based on isolation of bacteria from amniotic fluid, placenta and the foetus, confirming that colonisation begins before birth. This is supported by studies showing the myconium, or first stool, contained gut bacteria. This thinking that microbiome development can occur during foetal life and is further affected through factors such as: the mother’s diet, the type of birth, the colostrum and milk, and environment exposed to. This requires further studies to confirm but with other findings, appears to be a strong explanation.

Mother’s nutrition and the impact upon colostrum

Colostrum is defined as the first milk the mother produces. Not only is milk produced to nourish puppies with the nutrients they require for growth, but colostrum also conveys immunity to puppies. Colostrum is rich in antibodies, but also transfers intestinal microbiota species to the puppies. As only 5- 10 percent of immunoglobulins (which are immune proteins, and antibodies) can pass to through the placenta whilst the puppies are in utero, the colostrum is a crucial means of delivering this passive immunity to the puppies.

Transmission of gut microbiota is important to colonise the gut of the newborn puppies. This protects against a negative balance of gut bacteria, or dysbiosis, where the pathogenic gut bacteria are more prevalent, causing digestive distress. 15 species of gut bacteria were found within colostrum, alongside oligosaccharides, which also support gut health. Interestingly, the bacterial richness of the colostrum varied with the type of birth, with the colostrum of mothers of vaginally born puppies being richer than those born via caesarean section. How gut bacteria is found within the colostrum is still being researched, it is thought that an entero-mammary pathway is the key. A direct link between the gut and the mammary glands producing the milk! Puppies will develop their own gut microbiome population, but during the first 3 days of life, which is consequently when puppies are most vulnerable, is when their gut microbiome is made up of the gut bacteria delivered through colostrum.

The role of the diet is well known in its effect of shaping the intestinal microbiome. Nutrients and the metabolites from the microbial fermentation of food contribute to the normal development of a foetus, cementing the importance of good nutrition and a healthy microbiome. The supply of nutrients through the diet and good gut health during gestation are crucial for the mother’s health and immunity and also for the passive immunity transferred to puppies via the colostrum. Diet shapes the composition of the colostrum, which is delivered to puppies, having such a crucial impact on their health. A study supplementing the mother’s diet with pre and probiotics for four weeks found the highest antibody and immune proteins within the colostrum. This study did not show a difference in the gut bacteria within the colostrum, or sampled from the faeces, but the improvement in the immunity transferred to the newborn puppies is an incredible finding.

Puppy Microbiome effect on long term health

By building a puppy’s microbiome health from birth, their overall health benefits. A key issue in puppies is gut dysbiosis and diarrhoea, which affects around 25% of dogs during this growth phase. I explored this in more detail in “Digestive Health of young dogs and puppies”. By building and supporting gut microbiota and immunity puppies have a stronger start and their microbiome can be shaped for their whole life. Their microbiome health can be impacted through their mother’s nutrition, and so proper nourishment of the mother considering microbiome health can benefit mother and puppies.

References

1. Garrigues Q, Apper E, Chastant S, Mila H. Gut microbiota development in the growing dog: A dynamic process influenced by maternal, environmental and host factors. Frontiers in Veterinary Science. 2022; 9. https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.964649
2. Balouei F, Stefanon B, Sgorlon S, Sandri M. Factors Affecting Gut Microbiota of Puppies from Birth to Weaning. Animals. 2023; 13(4):578. https://doi.org/10.3390/ani13040578
3. Kajdič, L.; Plavec, T.; Zdovc, I.; Kalin, A.; Zakošek Pipan, M. Impact of Type of Parturition on Colostrum Microbiota Composition and Puppy Survival. Animals 2021, 11, 1897. https://doi.org/10.3390/ani11071897
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5. Alonge S, Aiudi GG, Lacalandra GM, Leoci R, Melandri M. Pre- and Probiotics to Increase the Immune Power of Colostrum in Dogs. Front Vet Sci. 2020 Nov 6;7:570414. doi: 10.3389/fvets.2020.570414. PMID: 33240949; PMCID: PMC7681242.