by Lisa Profera, MD 

What is your microbiome and why should you be thankful for it?

The good bacteria that reside in our gastrointestinal tract outnumber our own cells ten to one. They not only help us process and digest our food — they play a key role in our overall health. Hippocrates was correct in saying that “all disease begins in the gut.” It is vital to keep our microbiome functioning optimally; take care of it and be grateful for it. I have eluded to the importance of gut health in previous BRICK articles (December 2017, January 2018). Think of your microbiome as your hungry significant other. It needs to be nurtured and fed the right food or else it becomes cranky and can cause you much grief.

The familiar phrase “you are what you eat” should really be changed to “you are what you are able to digest.” You may be eating right, but is it being put to good use? Over the last 20+ years, our knowledge of the crucial role that gut flora play in our everyday lives has multiplied almost as fast as bacteria. Nowadays, we are being bombarded with so much information about probiotics and the microbiome of the gut — it’s almost overwhelming. But fear not, I will help you digest (pun intended) the current data so that you can make an informed decision about what is best for you.

All probiotics are NOT created equal. Just as we all have different fingerprints, we all have different gut flora. A one-size-fits-all approach to probiotics just doesn’t work. Your doctor may say, “just eat some yogurt and that’s all you need.” This may or may not serve you well. The strains of bacteria in most commercial yogurts have not been proven to be beneficial. Just one capsule of a good probiotic can contain the same of number of bacteria in 37 cups of yogurt.

Let’s backtrack here for a bit. Our lower gastrointestinal tract, or “gut” for short, is a highly sophisticated apparatus that is about 25 feet long (small intestines plus large intestines) and it’s responsible for converting the food we eat into absorbable essential nutrients while eliminating waste products. While we may have learned about the structure and function of the digestive system in high school biology class, little was known or taught about the 100 trillion organisms than reside within it. Yes, you read that correctly: there are ten times more bacteria living inside our gut than there are cells in our body! Each individual has a different concoction of the thousands of known species and over 70,000 strains identified thus far. So really, we are just beings that harbor five to six pounds of bacteria in a nice, warm, cushy environment. They are just doing us a favor by helping us digest our food and producing key vitamins to sustain life. They support 70% of our immune system. They have a vested interest in us staying alive. According to the brilliant scientists that conducted the Human Microbiome Project, we are the human “supraorganism,” and the “microbiome” (referring to our bacterial inhabitants) is a virtual organ within an organ. We cannot live without them, and vice versa.

You can decide if you want to be friends or enemies with your gut guests. Their composition and function (or dysfunction) is up to you. What you choose to eat, your lifestyle, your stress, and your previous medical history all have a direct effect on the gut. It all started at birth. The species and strains of your gut bacteria depend upon so many factors: vaginal delivery vs. C-section, breastfed vs. formula-fed, your mother’s flora and her overall health, early exposure to antibiotics, etc. Throughout life, your previous illnesses, travel history, and local environment all influence your microbiome. There is a myriad of factors that can lead to an unhealthy gut and consequently many diseases, including indigestion, irritable bowel syndrome, inflammatory bowel disease, diverticulitis, autoimmune disorders, cancer, other chronic inflammation, type II diabetes, and obesity.

Say you’d like to be better friends with your gut bacteria; what should you do? The definition of a probiotic, according to the World Health Organization, is something that contains “live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host.” As I stated earlier, not all probiotics are created equal, and each individual may benefit from different species and strains. First of all, a capsule of dead bacteria is of no use; you’re just wasting your money. The probiotic you choose to purchase must survive the manufacturing and shipping process. Heat kills bacteria, so any product that is not properly refrigerated or encapsulated is questionable. Once ingested, they must be able to survive the acidity of the stomach and be resistant to the effects of digestive enzymes so they can reach their final destination, your intestines. There is enough research out there now to prove that the benefits of probiotics are strain-specific, with strains derived from humans being the most desirable. Right now, the FDA does not require that the specific strain be printed out on the label. There is also no guarantee that the number of colony-forming units (CFUs) specified on the product label are 100% viable by the date of expiration. This is why it is crucial for you to do your homework and purchase a properly-stored and shipped product from a reliable company. This is where a knowledgeable healthcare professional can help guide you.

The science of probiotics is becoming so sophisticated that the concept of “precision probiotics” is now emerging. New research supports the idea that once an individual’s “core gut microbiome” becomes disrupted, disease is born. Some labs are even conducting DNA profiles of stool. You may be thinking that this is starting to sound complicated and expensive; well, it doesn’t have to be. For most healthy people, just getting on the right track is easy. Two of the most beneficial species to the human gut are Lactobacillus Acidophilus NCFM and Bifidobacterium lactis B107. These strains, along with a few others, should comprise the “core” of any good probiotic product you purchase. Diversity in strains that are scientifically proven to promote gut health is becoming more clinically important. Additional strains may be beneficial to target an individual’s specific conditions, such as irritable bowel syndrome, inflammatory bowel disease, gluten sensitivity, “leaky gut,” frequent urinary tract infections, traveler’s diarrhea, etc. The types and amounts of beneficial bacteria present in healthy babies, children, and adults differ greatly; logically, there are different products available for each. There are also probiotics tailored to help you fight off the common cold, experience less diarrhea when on antibiotics, and recolonize and restore the good GI tract flora after an insult such as a course of antibiotics or the stomach flu.

After reading this article, I hope that you are starting to develop a better understanding of what I mean when I say “be thankful for your microbiome.” This is a complicated topic, and I am here to help guide you to the best product for your individual needs. If you have further questions or concerns, feel free to contact me at or call toll-free 1-844-776-5888.

Help your gut help you.

Lisa Profera MD

Lisa Profera, M.D.
Lisa Profera, M.D. Author

Lisa Profera MD | Owner and Founder of PROJUVU MD Aesthetics and Lifestyle Medicine

Originally from New York, Dr. Profera received both a Bachelor of Science degree in Biochemistry and an MD from the State University of New York at Stony Brook. After completing residency at the University of Michigan, she worked as a primary care pediatrician in Ann Arbor for twenty-three years.She is passionate about integrating the best practices of Aesthetics and Rejuvenative Medicine to help patients look better and feel better. She believes in “projuvenation”; being proactive about rejuvenation and defying the aging process both inside and out. Dr. Profera and her husband live in downtown Ann Arbor and they have two daughters in college. Projuvu on facebook 

Please note that the information in this article has been designed to help educate the reader regarding the subject matter covered. This information is provided with the understanding that the author and any other entity referenced here are not liable for the misconception or misuse of the information provided. It is not provided to diagnose, prescribe, or treat any disease, illness, or injured condition of the body. The provider of this information shall have neither liability nor responsibility to any person or entity concerning any loss, damage, or injury caused or alleged to be caused directly or indirectly by this information. The information presented is in no way intended as a substitute for medical counseling or care. Anyone suffering from any disease, illness, or injury should consult a qualified healthcare professional. These statements have not been evaluated by the FDA.