Probiotics for Pregnancy

Dr Kate Stephens PhD Food and Microbial Sciences; Gut Microbiology (University of Reading), BSc Medical Microbiology

Many pregnant women take pregnancy supplements to support their baby’s development. But looking after their own health is just as important. After all, mum’s health has a direct impact on the health of her growing baby.

So, how can expectant mothers look after their health and well-being during their pregnancy? One easy option could be to supplement with friendly bacteria, known as probiotics.

This blog forms part 3 in the ‘Microbiome series’, the blog focuses predominantly on the microbiome in pregnancy and pregnancy safe probiotic strains. For more information on the microbiome see part 1 - The Microbiome - All You Need To Know or for a child’s microbiome Your Child's Microbiome.

Are probiotics safe in pregnancy?

Let’s start with the most important question - are probiotics safe to take during pregnancy?

Generally probiotics and prebiotics are considered safe during pregnancy. This has been shown in large scientific studies1,2. A number of organisations including Babycentre UK29  and the American Pregnancy Association30 have also suggested probiotic supplementation during pregnancy to be safe and beneficial.

However, there is still one probiotic in particular, Saccharomyces boulardii, that is lacking in clinical research in pregnant women. This unique probiotic strain has shown many positive health benefits, including: reducing diarrhoea, having anti-inflammatory effects and inhibiting the growth of harmful bugs. However, due to a lack of testing in this vulnerable subset of the population, pregnant women should exercise caution. Some researchers have therefore suggested either not to use it at all, or to check with a doctor before using it. Healthcare professionals can visit the Probiotics database to find out more about the research into Saccharomyces boulardii

Expectant mums who are considered ‘more at risk’, or those with a health condition (especially one related to the immune system) should always check with their GP before taking any pregnancy supplement, including probiotics.

If you are generally well and healthy and would like to take a probiotic, always check with the manufacturer’s guidelines, and ensure the probiotic strains are suitable in pregnancy. If in doubt, give the brand a call.

Now that we know that probiotics are largely considered safe in pregnancy, let’s take a look at how they work and some of the benefits these friendly bacteria may bring.

Pregnant woman

How do probiotics work during pregnancy?

Overall, probiotics help to rebalance the microbiome by topping up with levels of friendly bacteria. Once in the gut they can do many different jobs and support many aspects of health. Probiotics can be used by most people of all age groups.

OptiBac birth

In pregnancy, the microbiome is believed to play an important role in both mums and baby’s health. When a baby passes through the birthing canal they are exposed to thousands of microbes. It’s therefore important for mum to have lots of good bacteria so that they transfer to the newborn.

So, to understand how probiotics may be beneficial during pregnancy, we need to understand what happens to the microbiome throughout the trimesters.

During pregnancy there are many microbial, immunological, hormonal and metabolic changes- these all influence one another. We actually see some big changes to the microbiome. There are still some mixed reports regarding how the gut microbiome composition changes, but the following is generally accepted amongst scientists:

pregnancy infographic

Gut microbiome: During the first trimester, the microbiome is relatively stable and looks similar to that of a non-pregnant woman. As the pregnancy progresses, the microbiome composition changes. There is a reduction in the overall diversity of microbes and fewer friendly bacteria. Inflammation increases and there are higher levels of bacteria that give ‘more energy’. This makes sense as the body needs more energy to help with the growing baby. In fact, one study showed when a poo sample from a pregnant woman in her third trimester was given to a germ free (sterile) mouse, the mouse gained weight and the microbiome looked like a microbiome from an individual with metabolic syndrome or diabetes3. These changes are regarded a normal part of pregnancy; however, in some women, they could explain why gestational diabetes occurs.

Vaginal microbiome: As pregnancy progresses, the vaginal microbiome becomes less diverse and more dominant in friendly bacteria known as lactobacilli4. Lactobacilli have many protective effects; they help to create an environment for friendly microbes to thrive and inhibit the growth of many harmful ones. This is particularly important as vaginal infections such as bacterial vaginosis (BV) or thrush may increase the risk of recurrent miscarriages and pre term births5,6,7. Read more in Camilla's article about how pregnancy changes the vaginal microbiome.

Oral microbiome: an upcoming area of research is the changes to the oral microbiome. Pregnant women are at higher risks of oral health issues. This could be because the number of bacteria in the oral cavity increase; including bacteria associated with gingivitis and periodontal disease8.

On top of these natural changes, the microbiome can also be further affected by stress levels, diet and antibiotic use. These may impact mum’s health and baby’s health during gestation and post birth. Ultimately, they can reduce the level of friendly bacteria causing microbial imbalances (dysbiosis). To learn more, health professionals can read this article on the Probiotic Professionals site: Antibiotics during pregnancy may impair baby's immunity

For example, antibiotic use during pregnancy has been associated with higher numbers of harmful bugs (such as Escherichia coli and Staphylococcus spp.) in the vaginal tract9. High levels of these bugs in new-borns have been associated with colic, eczema and allergies10,11.

We can see that the microbiome naturally undergoes many changes and can also be easily influenced by numerous other factors affecting the microbial balance. These changes to the microbiome may affect both mum and baby’s future and current health. So, probiotics have a lot of potential to tip the balance back to a more positive state and support overall health.

Are there benefits of taking probiotics during pregnancy?

With all the body changes during pregnancy, pregnant women can support many aspects of their health naturally with probiotics. They may find their digestion is just not the same, or they may want to boost their immune system, or avoid developing health conditions they had suffered in a previous pregnancy.

Let’s take a look at some of the common pregnancy worries and what may help! 

Intimate health in pregnancy

Why? Vaginal infections can result in unwanted pregnancy complications. Therefore pregnant women need to take care of their vaginal health even before conception. Common over the counter medications can be useful to gain relief from an infection. However they often only treat the symptoms rather than get to the root cause. Probiotics that are known to reach the vaginal tract, can promote a healthy vaginal microbiome, which in turn may lower the risk of vaginal infections.

Strain focus

Combination of Lactobacillus rhamnosus GR-1® and Lactobacillus reuteri RC-14®: These two strains are the most researched strains in the world for vaginal health.  They’ve been researched in pregnant women and shown to reach the vaginal tract, even when taken orally. They have been shown to reduce the number of urinary tract infections and improve symptoms associated with bacterial vaginosis and thrush14,15,16. Health professionals can visit the Probiotics Database to read more about the research using Lactobacillus rhamnosus GR-1® and Lactobacillus reuteri RC-14®

Combination of Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus La-14®: These two strains have been researched in women with bacterial vaginosis and thrush. Together, they have improved symptoms and reduced the risk of recurrent infections17,18,19. Health professionals can visit this strain's entry in the Probiotics Database for more details about the research using Lactobacillus rhamnosus HN001.

OptiBac Probiotics - 'For Pregnancy'

Both Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus La-14® can be found in OptiBac 'For pregnancy'

Postnatal depression in pregnancy

Why? According to the NHS, it is thought at least 1 in 10 women suffer with postnatal depression20. The exact cause is unknown and is likely due to many different reasons. One of which could be the changes we see in the gut microbiome and the inflammation this causes. There is a strong connection between the gut and brain (known as the gut-brain axis), so any changes to the gut environment can affect our mood. The gut is responsible for making many hormones including our ‘happy’ hormone serotonin. To learn more, health professionals can read this article on the Probiotic Professionals site: Pregnancy and Mental Health

Strain focus

Lactobacillus rhamnosus HN001: One of the very few probiotic strains to be trialled specifically for postnatal depression. A gold standard trial including 380 pregnant women found L. rhamnosus HN001 was able to significantly lower depression and anxiety. The probiotic was taken during pregnancy and for six months post birth21. As mentioned above, health professionals can see further details of research using this strain on the Probiotics Database.

Happy pregnant woman

General immune health in pregnancy

Why? Pregnant women are more susceptible to coughs and colds, and this can be more of a worry in the first trimester. However, there’s actually not many choices available to pregnant women to boost their immune health. As 70% of the immune system lies in the gut, maintaining good gut health is vital. Some probiotic strains have been shown to reduce the risk of infections, boost immune cells, and reduce severity of, or recovery time from an infection.

Strain focus

Lactobacillus paracasei CASEI 431®: This strain has been trialled in thousands of individuals and has been shown to boost the immune system and reduce recovery time by an average of three days22.  This highly researched strain is also included in the Probiotics Database, where health professionals can see an overview the research using Lactobacillus paracasei CASEI 431® 

Gestational diabetes (GD) in pregnancy

Why? By the third trimester, the microbiome may resemble someone with diabetes or metabolic syndrome. These changes are considered natural and part of pregnancy. The problem may arise if a woman has existing problems with insulin management- increasing her risk of GD. For example, women over the age of 35, women with a high BMI, and women who had GD in previous pregnancies may all be at higher risk. GD can be tricky to manage and can cause further health implications for both mum and baby. Health professionals can learn more on the Probiotic Professionals site: Can 'Synbiotics' improve symtoms of gestational diabetes?

Strain focus:

Lactobacillus rhamnosus HN001: This is one of only a few strains of probiotic to have research on GD. Pregnant women who took this probiotic during pregnancy had a general reduced risk of GD. The findings were significant for women at higher risks e.g. those over 35 and women who developed GD in previous pregnancies. In fact, no women developed GD even if they had had it previously23.

Health professionals can review this research on the  Probiotics Database.

IBS and bloating in pregnancy

Why? Digestive health supports overall health. It is important that pregnant women are digesting their food, and absorbing their nutrients well. Probiotics provide many digestive enzymes, helping us to digest our food. However, it is vital that the gut environment is healthy and the gut cells are well protected- as it is these that ensure good absorption. Gut cells have little structures called villi (Glossary definition: villi) on them. These villi increase the surface area allowing efficient absorption of nutrients. Probiotics and friendly bacteria can protect villi from damage from toxins and harmful bacteria. Poor gut health can result in poorly digested food and might mean that additional pregnancy supplements are not efficiently absorbed.  On top of this, digestive complaints including IBS, abdominal pain and bloating are also common in pregnancy.

Strain focus

Lactobacillus acidophilus NCFM®: This is one of the most researched probiotic strains for digestive health. It’s been shown to bind to gut cells, support a healthy gut environment and significantly improve abdominal pain and bloating24. Health practitioners please visit the Probiotics Database to read more about Lactobacillus acidophilus NCFM®

Lactobacillus casei Shirota®: A well-researched strain supporting gut function. The strain has been shown to improve IBS symptoms and increase the numbers of friendly bacteria in the gut25.​ Health professionals can visit this strain's entry in the Probiotics Database to read more about the research using Lactobacillus casei Shirota®

Bifidobacterium infantis 35624 : This strain has shown good results for IBS. In a gold standard trial it’s been shown to improve overall IBS functions, particularly abdominal pain and bloating26 This strain is also featured in the Probiotics Database on the Professionals site - healthcare practitioners can use this link to read more about Bifidobacterium infantis 35624

Regularity in pregnancy

Why? High levels of pregnancy hormones such as progesterone can cause occasional regularity issues during pregnancy. In addition, reduced levels of friendly bacteria can affect the overall gut environment which can slow down gut movements.  Often pregnant women do not want to take pharmaceutical laxatives and their long-term use can lead to lazy gut. However, probiotics are gentle and non-habit forming, and offer a natural option.

Strain focus

Bifidobacterium lactis HN019: Highly researched to improve occasional regularity issues, gut transit times and promote healthy gut function12. The strain has been trialled in hundreds of pregnant women. Healthcare practitioners may like to take a look at this highly-researched strain's entry in the Probiotics Data base: Bifidobacterium lactis HN019

Bifidobacterium lactis BB-12®: Researched in thousands of individuals and has been shown to ease occasional irregularity and increase number of bowel movements each week13. For the benefit of health professionals, an overview of the most significant trials using Bifidobacterium lactis BB-12®  can be viewed in the Probiotics Database.

Prebiotics are also used to ease occasional regularity issues. When prebiotics are used in the gut by friendly bacteria, the bacteria produce short chain fatty acids which can stimulate natural bowel movements and promote a healthy gut environment.

Morning sickness in pregnancy

Why? The increase in pregnancy hormones can cause nausea and sickness. It is particularly common during the first trimester. There is no research specifically looking into probiotics and morning sickness. B. lactis HN019 has been shown to reduce nausea in non-pregnant women, so this may be of benefit12. Often pregnant women with nausea or sickness tend to have low energy levels and the sickness may impact their gut microbiome. Taking a probiotic helps to top up the levels of friendly bacteria and boost energy levels.

When should I start taking probiotics in pregnancy?

Probiotics may have more benefit the earlier they are taken in pregnancy. The study for gestational diabetes for example was given to women at about 14-16 weeks. Studies looking into allergies and eczema in babies and children found that supplementation in pregnancy from 14 weeks again was beneficial. Other studies have showed that supplementation in the last month also gave protective effects against eczema, allergies and supported immune development in the newborn27,28. Probiotics for vaginal health should be taken sooner rather than later.

So really it is never too late, or too early!

Hopefully all this information has highlighted how probiotics in pregnancy can be a natural and effective way to support a pregnant woman’s health. A happy and healthy mum increases the chance of a happy and healthy baby!

Remember if in doubt about the research, safety or when to start, always give the brand a call or email and discuss options that will suit your needs.

References

1. Elias J et al., "Are probiotics safe for use during pregnancy and lactation?," Can Fam Physician, pp. 57 (3): 299-301, 2011.

2. Dugoua J et al., "Probiotic safety in pregnancy: a systematic review and meta analysis of randomised controlled trials of Lactobacillus, Bifidobacterium and Saccharomyces spp.," J Obstet Gynaecol Can, pp. 31 (6): 542-552, 2009.

3. Koren O et al., "Host remodeling of the gut microbiome and metabolic changes during pregnancy," Cell, pp. 150 (3): 470-480, 2012.

4. Aagaard K et al., "). A metagenomic approach to characterization of the vaginal microbiome signature in pregnancy," PLoS ONE, p. 7:e36466, 2012.

5. DiGuilio DB et al., "Prevalence and diversity of microbes in the amniotic fluid, the fetal inflammatory response, and pregnancy outcome in women with preterm pre-labor rupture of membranes," Am J Reprod Immunol, pp. 64: 38-57, 2010.

6. Farr A et al., "Effect of asymptomatic vaginal colonization with Candida albicans on pregnancy outcome," Acta Obstet Gynecol Scand, p. 94:989–996., 2015.

7. Zhang et al., "Alteration of vaginal microbiota in patients with unexplained recurrent miscarriage," Exp Ther Med. , p. 17(5): 3307–3316, 2019.

8. Fujiwara N et al., "Significant increase of oral bacteria in the early pregnancy period in Japanese women.," J. Investig. Clin. Dent, p. doi: 10.1111/jicd.12189, 2015.

9. Stokholm et al., "Antibiotic use during pregnancy alters the commensal vaginal microbiota," Clinical Microbiology and Infection, pp. 20 (7): 629-635, 2014.

10. Dubois N et al., "Characterising the intestinal microbiome in infantile colic: findings based on an integrative review of the literature," Biological Research for Nursing , p. 18 (3): doi:10.1177/1099800415620840, 2016.

11. Wong B et al., "Exploring the Science behind Bifidobacterium breve M-16V in infant health.," Nutrients, p. 11 (8); 1724 doi: 10.3390/nu11081724, 2019.

12. Waller P et al., "Dose-response effect of Bifidobacterium lactis HN019 on whole gut," Scandinavian Journal of Gastroenterology,, p. 46: 1057–1064, 2011.

13. Eskesen D et al., "Effect of the probiotic strain Bifidobacterium animalis subsp. lactis, BB-12®, on defecation frequency in healthy subjects with low defecation frequency and abdominal discomfort: a randomised, double-blind, placebo-controlled, parallel-group trial," British Journal of Nutrition , p. doi:10.1017/S0007114515003347, 2015 .

14. Beerepoot M et al., "Lactobacilli vs antibiotics to prevent urinary tract infections: a randomized, double-blind, noninferiority trial in postmenopausal women," Arch Intern Med, vol. 172, no. 9, pp. 704-712, 2012.

15. Martinez M et al., "Improved treatment of vulvovaginal candidiasis with fluconazole plus probiotic Lactobacillus rhamnosus GR-1® and Lactobacillus reuteri RC-14®," Lett Appl Microbiol., vol. 48, no. 3, pp. 269-74., 2009.

16. Anukam K et al., "Augmentation of antimicrobioal metronidazole therapy of bacterial vaginosis with oral probiotic Lactobacillus rhamnosus GR-1® and Lactobacilus reuteri RC-14®: randomized,," Microbes Infect., vol. 8, no. 6, pp. 1450-4., 2006.

17. Russo R et al., "Study on the effects of an oral lactobacilli and lactoferrin complex in women with intermediate vaginal microbiota," Archives of Gynacology and Obstetrics, pp. doi: 10.1007/s00404-0.18-4771-z, 2018.

18. Russo R et al., "Randomised clinical trial in women with recurrent vulvovaginal candidiasis: efficacy of probiotics and lactoferrin as maintenance treatment," Mycoses, p. DOI: 10.1111/myc.12883, 2019a.

19. Russo R et al., "Evidence based mixture containing Lactobacillus strains and lactoferrin to prevent recurrent bacterial vaginosis: a double blind, placebo controlled, randomised clinical trial," Beneficial Microbes, pp. 10 (1): 19-26, 2019b.

20. NHS, "Overview: Postnatal Depression," 12 December 2018. [Online]. Available: https://www.nhs.uk/conditions/post-natal-depression/.

21. Slykerman R et al., "Effect of Lactobacillus rhamnosus HN001 in pregnancy on postpartum symptoms of depression and anxiety: a randomised double blind placebo controlled trial," EBioMedicine, pp. 24, 159-165, 2017.

22. Jesperson et al., "Effect of Lactobacillus paracasei subsp. paracasei, L. casei 431 on immune response to influenza vaccination and upper respiratory tract infections in healthy adult volunteers: a randomized, double-blind, placebo-controlled, parallel-group study," AJCN, vol. 101, no. 6, pp. 1188- 1196, 2015 .

23. Wickens K et al., "Early pregnancy probiotic supplementation with Lactobacillus rhamnosus HN001 may reduce the prevalence of gestational diabetes mellitus: a randomised controlled trial," British Journal of Nutrition, pp. 117, 804-813, 2017.

24. Lyra et al., "Irritable bowel syndrome symptom severity improves equally with probiotic and placebo," World Journal of Gastroenterology, vol. 22, no. 48, pp. 10631-10642, 2016.

25. Thijssen AY et al., "A randomized, placebo-controlled double blind study to assess the efficacy of a probiotic dairy product containing Lactobacillus casei Shirota on symptoms of irritable bowel syndrome," Gastroenterology,, vol. 140, p. S609, 2011.

26. Whorwell P et al., "Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome," American Journal of Gastroenterology, vol. 101, pp. 1581-1590, 2006.

27. Wickens K et al., "A differential effect of 2 probiotics in the prevention of eczema and atopy: a double blind, randomised, placebo controlled trial," Atopic dermatitis and skin disease, pp. 122 (4): 788-794, 2008.

28.Prescott SL et al., "Supplementation with Lactobacillus rhamnosus or Bifidobacterium lactis probiotics in pregnancy increases cord blood IFNy and breast milk transforming growth factor B and immunoglobin A detection," Clinical and experimental Allergy , pp. 38 (10): 1606- 1614, 2008.

29. BabyCentre Medical Advisory Board, "Probiotics and prebiotics in pregnancy," 2020. https://www.babycentre.co.uk/a1025252/probiotics-and-prebiotics-in-pregnancy

30. American Pregnancy Association, "Probiotics During Pregnancy," 2020. https://americanpregnancy.org/pregnancy-health/probiotics-during-pregnancy/