Hormones, Probiotics, and the Human Microbiome

Hormones, Probiotics, and the Human Microbiome

Adapted from the Connections eBook Probiotic Potential

Written by Carol Petersen RPh, CNP 
Reviewed and Updated by Michelle Violi PharmD 
Published by Women’s International Pharmacy

The microbiome organ is a collection of microbes or single-celled microorganisms—called microflora—that live on and in the body. The human body contains 100 trillion cells, and 90% of them are not even our own—nearly all of these are bacteria; the rest are yeasts and parasites. These microbes are incredibly diverse in size, shape, col­or and growth rates, and may include as many as 1,000 different species.

Among our body’s microbes you will find:

  • The “good” – Probiotics like Lactobacillus, a strain of bacteria commonly found in yogurts with active cultures.
  • The “bad” – Bacteria that usually result in serious illness, such as Salmonella.
  • The “risky” – Several bacterial species that are beneficial when they are in the right place and quantity, but may lead to health issues if their numbers are unbalanced or if they are located in the wrong part of the body. For example, species of Klebsiella make vitamins B12 and K when they’re in the small intestine, but may cause pneumonia when they’re inside the lungs.

The microbiome begins developing at birth and changes throughout our lifetime. Environment plays a larger role in determining microbiome makeup and health than genetics, which explains why members of the same household may have similar conditions even without being genetically related.

Microbial imbalance in our gut can affect other systems in our body, including our hormonal system. The digestive system plays an important role in the proper disposal of es­trogens from the body. When the flora in the intestines is disturbed, estrogen that should be excreted may instead be recycled into the bloodstream, creating hormone imbalance.

The development and changing of the microbiome over time may coincide with other physical changes. Many major life changes such as puberty, pregnancy, and menopause that affect the microbiome also affect hormone balance: University of Utah’s webpage Your Changing Microbiome provides just a few examples, saying: “puberty affects skin microbes by causing changes in skin oils. And pregnancy brings on changes in the vaginal microbiome: species start to grow that will colonize and benefit the baby as it’s born.”

Optimizing Microbiome Health to Maintain Hormone Balance

A probiotic—literally, “for life” in Greek—is defined as “a preparation or a product containing a sufficient number of live microorganisms to alter the flora of the host and bring about beneficial health effects.” In short, probiotics are “friendly” bacteria (and sometimes fungi) that we import into our system to hold more dangerous mi­crobes in check. A growing number of scientific studies have found that probiotics may aid both digestive and immune system health.

Yogurt, aged cheese, and many other cultured and fermented foods make up this category of “superfoods.” Probiotic foods or supplements are generally safe and widely available. Most people find them both tasty and easy to digest.

In general, probiotics promote healthy diges­tion. Microbes in the intestines make short-chain fatty acids (needed for GI tract health), antioxi­dants, amino acids, and vitamin K. Nutrients in fermented foods absorb more readily than nutrients in unfermented foods. Fer­mented foods use agents such as yeast, bacterium, molds, or enzymes to break down a substance into simpler substances; examples include converting milk to yogurt or cheese, fermenting soy to make miso, and fer­menting cabbage to make kimchi or sauerkraut.

Getting a beneficial effect for individ­ual health need depends on various factors, including:

  • The strain of probiotics selected and how the body can use it
  • The numbers of live probiotics in the pur­chased product, and whether they are stored and taken properly

Safety, Storage, and Use of Probiotics

Probiotics are safe for the majority of people, except for those at high risk for infections of all types (such as those with HIV/AIDS or cancer), or those taking immune-suppressive steroids. It is always advisable to check with your prac­titioner before taking any new supplements, as probiotics do have the potential to interact with some medications. Moreover, your practitioner can help you select the probiotic that is best suited to treating your particular condition, notes Dr. Kelly Dowhower Karpa in the book Bacteria for Breakfast: “You may have to search for the right probiotic, the appropriate number of microorganisms, or the necessary combination of probiotics until you find the right mix to successfully fill the bacterial niche missing in your gastrointestinal tract.”

Whether taken by pill (as a supplement) or by plate (in food), either form of probiotics can be effective as long as proper procedures of storage and ingestion are followed. Although it might seem that pill supplements would be required for the lactose-intolerant, that is not neces­sarily the case. Probiotics have been shown to help break down lactose, reducing symptoms of the illness and allowing sufferers to reintroduce dairy into their diet—at least in the form of yogurt and other fermented products.

Any form of probiotic should be purchased with care to ensure you are receiving the promised strain and quantity of live bacteria (or, in some cases, fungi), and that it has been properly stored. Foods containing live cultures must be kept refrigerated, and storage dates must be strictly followed. In Acidophilus and Your Health, author Frank Murray includes this advice when purchasing yogurts:

  • Always purchase yogurt with “live, active cultures,” including Lactobacillus acidophilus
  • Avoid frozen yogurt or pudding-style yogurts, which have stabilizing chemicals and artificial sweeteners added


Probiotics play an integral part in many of the body’s functions, including:

  • Microbiome health
  • Proper digestion
  • Hormone balance
  • Strengthening the immune system
  • Prevention of allergy development

When trying to incorporate dietary or supplemental probiotics into your lifestyle, recommendations from your healthcare practi­tioner may help guide you to reliable products from proven manufacturers. Finding the right probiotic for your individual needs may help optimize microbiome health—and, by extension, hormone balance and overall wellness.

Read the complete Connections e-Book:

Probiotic Potential

Using “Friendly” Bacteria to Promote Healthy Digestion, Strengthen Immunity, and More

  • Karpa KD. Bacteria For Breakfast: Probiotics for Good Health. Trafford Publishing; Victoria, BC, Cana­da; 2003.
  • Murray F. Acidophilus and Your Health. Keats Publishing Inc.; New Canaan, CT; 1998.
  • Petersen C, Violi M. Probiotic Potential. Women’s International Pharmacy. https://www.womensinternational.com/portfolio-items/probiotics/. Reviewed and updated August 2019.
Hormones, Probiotics, and the Human Microbiome2019-08-23T12:19:11-05:00

A New Organ Has Been Identified: The Human Microbiome

A New Organ Has Been Identified: The Human Microbiome

Written by Carol Petersen, RPh, CNP – Women’s International Pharmacy

That’s right. It has been there all along, but we are just now getting around to noticing it. This organ weighs about three pounds and by weight, it is the largest organ in the human body. The organ is a collection of microbes or single celled organisms that live on and in your body. It has been named the human microbiome.

Our bodies are made up of about 10 trillion cells, but we host approximately 100 trillion microbe cells. To put a trillion in perspective, if we were to live for one trillion seconds, our life span would exceed 32,000 years. Based on the math, we are only 10% human!

It was surprising to the scientific community when the Human Genome Project was completely finished earlier than anyone predicted. It turns out that human beings only have about 20,000 genes. We have significantly fewer genes than rice or corn! However, we also carry and use two to twenty million genes from the vast number of microbes we host. If we compare the number of human genes to microbe genes rather than the number of human to microbe cells in our body, we are 99% microbe!

In an effort to identify the microbes living on and in the human body, the Human Microbiome Project was begun in 2008. It was a massive undertaking funded by the National Institute of Health (NIH) to the tune of 170 million dollars. More than 200 scientists worked on the project. The Human Microbiome Project continues to generate significant scientific findings to this day. Some examples include new technologies that sequence genes and computer programs which can handle vast amounts of data. These discoveries are opening up very exciting new areas of research.

Our human microbiome makes us more individually unique than our genetic composition. Genetically we are 99% identical to other human beings, but we only share about 10% with other human microbiomes. Even genetically identical twins do not share the same microbiome.

Since the time of Louis Pasteur, we have been operating on the “germ theory of disease.” This philosophy states that diseases are caused by microorganisms. One might assume that we are hapless victims of microbial assaults and to save ourselves we must use antiseptics or antibiotics to stem the attack. The latest findings of the Human Microbiome Project cause one to think twice about this assumption.

Normally, we live in harmony with these vast numbers of microbes. In fact, a healthy microbiome aids us in some essential life processes such as digestion, the integrity of our immune systems and even our behavior. However, many different things can cause changes in the composition of an individual’s microbiome. Diet, drugs, birth order, age, sexual partners and especially antibiotics are just a few examples. An altered or weakened human microbiome has been linked to diseases such as obesity, arthritis, autism, and depression.

The human microbiome also plays a role in hormone production and regulation in the body. For example, an organism called Clostridium scindens, which resides in the gastrointestinal tract, has been identified as capable of transforming cortisol type hormones to testosterone and other androgens. Surprisingly, our sex glands are not the only source of testosterone in our bodies! The genes of some bacteria in the gut are able to produce estrobolome, an enzyme which helps metabolize estrogens. A disordered microbiome in the digestive tract could be the underlying cause of estrogen dominance producing symptoms of infertility, PMS, heavy bleeding, cramps, polycystic ovary disease and more

Additionally, an overgrowth of yeast and related organisms in the microbiome has many documented effects on various hormones. Request a yeast information packet which contains a detailed chart of specific organisms and their impact on hormone balance.

Since so many different things can alter the microbiome, research is focusing on how to repair a damaged microbiome system. For example, scientists have found altering the microbiome normalizes the weight of obese mice. We have also seen amazing results with procedures called fecal transfers where the microbiome of a healthy person is essentially implanted into the body of a sick person.

We have long been using probiotics in the forms of specific cultures or in fermented foods. We also know about the use of substances which we call prebiotics such as inulin or fructo-oligosaccharides (FOS) that can nurture the growth of certain species of microbes. We are just now beginning to understand which species of microbes need to be re-established and how to reintroduce these specific strains with supplementation. For the consumer, the marketplace for probiotics can be confusing and frustrating. There may be very helpful probiotic strains available, but we still lack the knowledge of which probiotic strain we should choose for each particular condition.

While the science is still evolving, there is a lot we can do in the meantime. We can avoid the frivolous use of antibiotics and avoid eating antibiotic treated meats. We can carefully consider the need for certain medication before using them. Drugs like oral contraceptives may damage the microbiome. We can clean up our diet and avoid dairy, sugar and gluten which can adversely affect the microbiome. We can eat fermented foods like sauerkraut, kimchi, kombucha, and live culture yogurt daily. We can add probiotics and prebiotics to our daily regimen. Because the science has not caught up yet, try a variety of products to determine which might have the best effect for you. We are clearly entering an exciting new world of understanding how we, as human beings, interact with the invisible yet powerful world of microbes.

A New Organ Has Been Identified: The Human Microbiome2018-04-03T16:31:26-05:00

The Lyme Disease Merry-Go-Round

The Lyme Disease Merry-Go-Round: Hormones, the Immune System, and Yeast

Written by Kathy Lynch, PharmD – Women’s International Pharmacy


Patients with chronic Lyme disease have weakened immune systems which may allow intestinal yeast to overgrow. Antibiotics, the mainstay of Lyme disease therapy, destroy the beneficial gut bacteria which keep yeast overgrowth in check. Yeast, in turn, depresses the immune system even further. It also binds up estrogen, making it unavailable to the cells that need it the most. Thus patients with Lyme disease may get sicker and sicker due to a compromised immune system, hormone imbalance, and yeast overgrowth.

A low sugar, low carbohydrate diet can kill off yeast while strengthening the immune system. Acidophilus and other anti-yeast supplements like aged garlic extract can help as well. (See our A Connection with Yeast newsletter.) Practitioners who treat yeast with immunotherapy can be found at the American Academy of Environmental Medicine website.

Marlene Kunold, a German practitioner who specializes in the treatment of Lyme disease, believes that healing may be incomplete until the adrenal and thyroid glands are adequately supported. Researchers have found that the adrenal glands have a positive effect on immunity. And natural killer cells, part of the immune system’s first line of defense, are more active when thyroid function is optimal.

Dr. William Hrushesky believes that estrogen dominance can decrease the activity of natural killer cells and other immune system components. Low estrogen levels can do the same thing. Progesterone can help offset estrogen dominance but may cause yeast overgrowth in susceptible individuals. It is important that patients with Lyme disease have access to medical professionals with knowledge of hormones, the immune system, and yeast.

The Lyme Disease Merry-Go-Round2018-04-05T13:15:46-05:00

Endometriosis, Yeast, and Hormones

Endometriosis, Yeast, and Hormones

Written by Kathy Lynch, PharmD – Women’s International Pharmacy

Wayne Konetzki, MD, a member of the American Academy of Environmental Medicine (AAEM), has observed that most women with endometriosis have allergies to Candida albicans. He has also discovered that these same women may have sensitivities to luteinizing hormone, as well as to estrogen and progesterone.

Dr. Konetzki claims that Candida albicans yeast may have either progesterone and/or estrogen receptors on their cell walls. Increased hormone blood levels may cause yeast to overgrow, which then exacerbates endometriosis symptoms.

Endometriosis symptoms often diminish with anti-yeast treatment, which of course includes eliminating sugar from the diet. Endometriosis sufferers who are hypersensitive to hormones may also benefit from the desensitization techniques used by AAEM practitioners.

Endometriosis, Yeast, and Hormones2018-04-05T12:12:56-05:00

Boric Acid for Treatment-Resistant Vaginal Infections

Boric Acid for Treatment-Resistant Vaginal Infections

Written by Kathy Lynch, PharmD – Women’s International Pharmacy

Boric acid is a mild antiseptic with anti-fungal, anti-viral and anti-bacterial properties. Vaginal infections may be difficult to resolve if resistance to standard drugs develops. A clinical review of 14 studies found boric acid to be a safe and effective treatment for vaginal infections caused by resistant yeast. A smaller study of 58 women found that boric acid may provide additional benefit to treatment regimens for resistant bacterial infection.

Ask your compounder about boric acid suppositories or vaginal capsules for vaginal yeast and bacterial infections. Note that this preparation should NEVER be taken by mouth.

Boric Acid for Treatment-Resistant Vaginal Infections2018-04-10T14:38:07-05:00