Can probiotic treatment improve your microbiome before fertility treatment?

Maria Navas
Nutritionist, Maria Navas Nutrition, Health and Women

Fertility & microbiome, Lifestyle and Fertility

From this video you will find out:
  • What factors influence your microbiota?
  • What role does the uterine microbiome play in fertility?
  • What foods are anti-inflammatory for the gut, and why are they important?
  • How do probiotics affect the microbiota?
  • Does a vaginal lactobacilli probiotic treatment improve a vaginal microbiome before fertility treatment?

Can probiotic treatment improve your microbiome before fertility treatment?

During this event, Maria Navas, Nutritionist and an expert in the microbiome and women’s health, explained whether probiotics can influence your microbiome and what to do before your IVF treatment.

Microbiome & its role in endometrial health and fertility

In our endometrium, we have microbiota, and the most beneficial microbiota for getting pregnant and undergoing fertility treatments consists of 90% lactobacillus bacteria. Studies have shown that women with lower levels of lactobacillus may face greater difficulties in conceiving. However, it’s important to note that not having exactly 90% lactobacillus doesn’t mean you can’t get pregnant. It simply serves as a predictor.

There are other ways to enhance our microbiome. While tests are available, there’s a simple and free method we can use – paying attention to our bodies and being aware of signs that may indicate an alteration in our microbiota. Specifically, in terms of the reproductive system, if you experience any vaginal discomfort, dryness, itching, or inflammation, it could be a sign of the presence of microorganisms that shouldn’t be there. Similarly, digestive problems like candida infections can indicate issues in the gastrointestinal tract, which is connected to the vaginal microbiota.

Our skin is also connected to our gut microbiota. If you notice rashes, redness, dermatitis, or psoriasis, it could be another sign of an imbalanced microbiota. Additionally, symptoms such as tiredness, mood swings, or anxiety may also be connected to microbiota health.

Taking care of our microbiota shouldn’t be reserved for times when problems arise. It’s essential to proactively care for our microbiota throughout our lives. The factors that influence our microbiota are cumulative, starting from birth and continuing throughout our lifetime. Although changes we make today can yield results tomorrow, everything we’ve been exposed to, even since birth, has impacted our microbiota.

Factors that influence our microbiota include the method of birth (vaginal or C-section), breastfeeding (receiving microbes from the mother’s milk), the environment we grow up in (such as school or home-schooling), exposure to different microbiomes (like other children), living in urban or rural areas, contact with animals, and the use of antibiotics.

Antibiotic therapy is another important consideration. If someone frequently takes antibiotics, it is essential to take care of their microbiota. This is especially true for individuals who took a lot of antibiotics during their childhood. Excessive use of stomach protectors, a common practice in Spain for people experiencing reflux, can negatively affect the microbiota in the stomach and gut, which may extend to the vagina and endometrium. Taking care of our gut health is crucial since it not only affects the microbiota in the gut but also in other parts of the body.

Factors that influence microbiota

Various factors can disrupt the microbiota, including surgical interventions that involve the use of medications, alcohol, and drugs. Psychological health, such as anxiety and depression, is closely connected to gut health. Additionally, certain professions expose individuals to toxins regularly, which can impact the microbiota. For example, living in a city exposes us to toxins present in the air, which can harm beneficial bacteria.

Probiotics refer to the live bacteria and other microorganisms found in capsules or sachets. Prebiotics, on the other hand, are the food sources for these bacteria. Postbiotics are the byproducts or components of dead bacteria, such as those found in yoghurt. Studies have shown that postbiotics can affect our health.

Microbiota transplantation is another approach. It can be performed through a faecal or vaginal transplant. However, vaginal transplant is not widely practised in Spain, while faecal transplant is only used in specific situations. For women with microbiota imbalances that are difficult to restore, vaginal transplant involves taking microbiota from a healthy woman with a high abundance of lactobacillus and transferring it to a woman with microbiota issues. This procedure can improve the situation significantly.
Now, let’s discuss the “Healthy Plate,” which is a visual representation of a balanced and healthy diet. It helps us understand the different food groups and their impact on our microbiota. First, we have the vegetables, which should make up half of our plate. It is important to eat a variety of vegetables in different colours and cooked in various ways. Vegetables provide minerals, vitamins, and fibre, which are essential for our microbiota. Fibre, in particular, is a primary food source for the beneficial bacteria we want to cultivate. Additionally, the colourful compounds found in certain vegetables and fruits, like blueberries, can also benefit our microbiome.

Next, we have carbohydrates. When it comes to fertility-focused diets, people often wonder whether they should consume carbohydrates or avoid gluten. The key is to consider the amount and type of carbohydrates. Whole grains, such as brown rice, are highly recommended due to their high fibre content, which supports the microbiota. In contrast, refined grains like white rice or processed corn products with added sugars are less beneficial. It’s important to note that individual cases may vary, and personalized recommendations should be considered.

Lastly, gluten can be inflammatory, and it’s important to consider this when planning a diet. However, the best approach for individuals with gluten sensitivity or intolerance should be discussed on a case-by-case basis.

To maintain a healthy microbiota, it is crucial to prioritize a nutritious diet, avoid nutritional deficiencies, and support hormonal balance. By understanding the factors that impact our microbiota and making informed choices, we can work towards improving our gut health and overall well-being.

An anti-inflammatory diet

An anti-inflammatory diet is ideal for maintaining overall health. However, there may be certain moments in our lives when following a stricter anti-inflammatory diet could be beneficial. During these periods, it might be advisable to eliminate gluten from our diet. Although some individuals may not experience any issues with gluten, temporarily removing it for two or three months can be positive for both our microbiome and overall system. This helps avoid triggering small inflammatory reactions, even if their impact is minimal.

The impact of carbohydrates on our diet depends on timing and our activities. Additionally, the amount of protein we consume is crucial, and it is common for many women to not consume enough protein. Ensuring an adequate protein intake in every meal, including breakfast, lunch, and dinner, is important. Ideally, proteins should constitute one-quarter of our plate. While carbohydrates and proteins have specific proportions on the plate, slightly increasing the amount of protein is acceptable. However, it is important to consume high-quality protein, such as meat from chickens raised in the countryside with a good diet, rather than stressed chickens fed low-quality food. The quality of the protein we consume affects the final food’s quality.

Dairy is another dietary consideration. Similar to gluten, some individuals may not experience any adverse effects from consuming dairy products. However, during certain periods, it might be beneficial to temporarily eliminate dairy from our diet. If dairy is reintroduced, it should be of the highest possible quality. When it comes to fats, they should always be included in every meal, and high-quality fats should be chosen. Opting for unprocessed fats, such as avocados or extra virgin olive oil, is preferable. These fats possess anti-inflammatory properties that promote a healthier microbiota.

Moving on to eating habits, it is often believed that we must eat five times a day. However, from a microbiota perspective, this is not true and can be unhealthy. For the best microbiota health, it is recommended to eat two to three meals a day. Additionally, incorporating plenty of colourful vegetables and spices into our diet is essential. The colours of these foods can provide nourishment for our microbiomes, even if the relationship is indirect.

Including oily fish, such as salmon, in our diet is beneficial due to its high-quality fats. However, dietary recommendations should be individualized based on personal needs. It is advisable to consult with a doctor or a professional guiding you to determine appropriate supplementations.
Regarding dinner, in Spain, it is customary to have dinner late, around 10 or 11 PM. It is an important point to consider, but the timing may vary depending on the country. A 12-hour fasting period is acceptable, but aggressive intermittent fasting during fertility treatments and when trying to conceive might not provide sufficient nutrients.

Eating fresh, unprocessed foods, such as vegetables and high-quality animal products, is like composting, filling the compost bin with nutritious materials. On the other hand, consuming processed foods fills the “plastic bin” with waste. Striving to keep the “plastic bin” less full by reducing processed food consumption is recommended.

Probiotics & recent studies

The topic of probiotics and their effects on fertility is relatively new, with numerous studies conducted in recent years. Unlike taking an aspirin for a headache, determining the best approach for probiotic use is not straightforward. However, certain bacteria, such as Lactobacillus crispatus and Lactobacillus salivaros, have shown positive effects on fertility and vaginal health. It is important to consider both fertility-focused and intimate women’s health probiotics when making a selection.

Several studies have explored the duration of probiotic interventions. For example, a 3-day intervention did not affect the vaginal colonization of Lactobacillus or impact embryo transfer. Longer interventions, such as the 60-day study, showed no difference in colonization or pH but indicated an improvement in vaginal health. It is worth noting that a more extended intervention may yield different results, suggesting that probiotic use should be approached as a long-term commitment.

Another study conducted over 180 days compared reproductive failure and fertile women. The study aimed to assess the impact of Lactobacillus salivaros on vaginal parameters and pregnancy rates. Fertile women exhibited a higher presence of Lactobacillus compared to those with repetitive miscarriages. The oral administration of Lactobacillus salivaros resulted in a significant number of pregnancies among infertile women, along with notable improvements in vaginal health parameters.

When selecting a probiotic, it is crucial to consider individual circumstances. Probiotics designed for fertility may be suitable, but those targeting specific issues like Gardnerella or Candida should also be considered. It is recommended to consult with a healthcare professional to determine the most appropriate probiotic for your situation. Additionally, probiotics can be administered orally or vaginally. Oral probiotics may offer better treatment adherence, and when treatment ends, vaginal colonization remains better compared to vaginal administration.

It is essential to address the health of the vaginal mucosa or epithelium. Merely introducing bacteria to the vagina is insufficient if the environment is not conducive to their growth. Factors such as vaginal pH and moisture level play a crucial role in bacterial adherence. Addressing vaginal dryness and pH balance is vital, particularly during fertility treatments where vaginal dryness is common. Taking a holistic approach to vaginal health, including probiotics, is crucial.


In addition to probiotics, an anti-inflammatory and prebiotic diet is recommended. An anti-inflammatory diet reduces stress on the immune system, allowing it to identify and fight harmful bacteria. Prebiotics are foods that nourish the desired microbiota. It is also important to focus on lifestyle factors such as managing stress, getting adequate rest, engaging in physical activity, spending time outdoors, and maintaining a positive mindset. These lifestyle choices significantly impact overall health.
By considering these factors and taking a comprehensive approach to health, including probiotics, a healthy lifestyle, and adequate rest, individuals can optimize their fertility and overall well-being.

- Questions and Answers

What is the best food to eat on the day of embryo transfer and the following days?

The best food to eat on the day of embryo transfer and the following days would be a diet rich in good fats and vegetables. It’s recommended to be more restrictive in the month or week leading up to the transfer, avoiding dairy, gluten, sugar, processed food, and unfamiliar ingredients. It’s important to eat as healthy as possible during this time.

What should I eat during the hormonal stimulation period?

During the hormonal stimulation period, it’s common to experience stress and anxiety. Many women tend to seek comfort in food, such as bread with butter. However, it’s best to focus on having a nutritious breakfast with anti-inflammatory foods, including healthy fats and quality proteins. For lunch, incorporating a variety of vegetables is ideal. In the evening, reducing carbohydrate intake can be beneficial, but if you’re still hungry, opt for whole and high-fibre carbohydrate sources.

Streptococcus is found in the uterus. I did 4 rounds of antibiotics Lactobacillus to 80%. However, Streptococcus has gone up to 63%. In the given situation, where the Streptococcus level in the uterus fluctuated, what advice would you give?

Based on the provided information, it seems that the lactobacillus levels went up to 80% initially but dropped to 63% when the strep level decreased. In this situation, it’s important to take care of your diet and lifestyle. Additionally, continue taking probiotics to maintain a healthy balance. Ensure that you are using the right probiotics, as the increase in lactobacillus is a positive sign. Consult your healthcare provider to confirm if you are taking the appropriate probiotics.

How long before embryo transfer should I take vaginal probiotics?

Regarding the timing of vaginal probiotic use, I would suggest considering oral probiotics instead of vaginal ones. Oral probiotics can benefit your gut health and potentially address any underlying issues. It’s never too early to start working on improving your microbiota, especially if you suspect any problems.

Can you recommend good oral probiotics?

The choice of oral probiotics depends on individual cases, and it’s recommended to consult with your fertility specialist or nutritionist. In Spain, many people have had success with the QueenBiotic. However, it’s essential to find the probiotics that suit your specific needs and situation.

Can candida albicans prevent implantation, and what is the anti-candida diet?

Candida albicans can sometimes cause problems, but with dietary adjustments and probiotics, the situation can improve, and pregnancy can be achieved. The anti-candida diet involves minimizing carbohydrate intake, especially sugars, and opting for whole-grain options when consuming carbohydrates. The diet should focus on foods with a low glycemic index, along with an emphasis on healthy fats and proteins. Medication, herbal therapy, and probiotics can also be utilized to combat candida overgrowth.

Would you suggest a biopsy of the uterus and a test to examine the microbiome? I did this test, and the lactobacillus level was 6%, which was tested after 5 failed transfers.

Typically, in situations like this, these tests can be quite expensive, especially in Spain. I usually advise patients to consider the fact that you had a low percentage of lactobacillus, which is not a good number. Given that you have had 5 failed transfers, my recommendation would be to focus on improving your microbiota before spending more money on a similar test. Once you have worked on your microbiota and observed some changes, it might be beneficial to retest in the future. It’s important to note that the duration of intervention plays a role in the results. Studies have shown that interventions lasting 180 days yielded different results compared to those lasting only 3 days. So, if you have the time, consider working on your microbiota for a longer period, such as 2 or 3 months, before deciding whether to repeat the test or proceed with another transfer. Ultimately, the decision should be based on what you think is best for your situation. Sometimes, it simply takes time, and it may be more effective to repeat the test after a while rather than rushing into it.
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Maria Navas

Maria Navas

Maria Navas is a nutritionist located in Spain, she graduated in Human Nutrition and Dietetics. She began her journey in private practice in 2020, where she focused on improving women's habits. She soon identified a series of common problems in women. They were related to their hormonal status, which affects their mood, fatigue, weight problems, menstrual alterations, etc. She decided to train in this field to see how to improve this through nutrition and lifestyle. As a result of the Postgraduate Diploma in Clinical Nutrition, she realized that many diseases of this century go hand in hand with an alteration in the microbiota. She specialized in it through a Master's in Microbiota, Probiotics, and Prebiotics. Maria continues her work on constant training through courses, books, congresses, and experiences with her patients on a daily basis.
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Caroline Kulczycka

Caroline Kulczycka

Caroline Kulczycka is managing MyIVFAnswers.com and has been hosting IVFWEBINARS dedicated to patients struggling with infertility since 2020. She's highly motivated and believes that educating patients so that they can make informed decisions is essential in their IVF journey. In the past, she has been working as an International Patient Coordinator, where she was helping and directing patients on their right path. She also worked in the tourism industry, and dealt with international customers on a daily basis, including working abroad. In her free time, you’ll find her travelling, biking, learning new things, or spending time outdoors.
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