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Are You Ready To Finally Feel Better?

We help motivated adults struggling with cardiometabolic, hormonal, and digestive issues regain their energy, edge, and peak performance.

We focus on these three things so that people can enjoy a well-balanced, productive life looking and feeling their absolute best…without extreme lifestyle changes, or lifelong dependence on prescription drugs.

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Are You Struggling With...

Gut Imbalances

IBS, SIBO, Constipation, Diarrhea, Bloating
Long COVID recovery
Food Sensitivities & Allergies
Stealth Infections
Poor Immune Resilience

Hormonal Imbalances

Low Reproductive Hormones
Adrenal/Thyroid Issues
Loss Of Drive, Libido
Brain Fog & Chronic Fatigue
Lack of Focus & Low Performance

Cardiometabolic Imbalances

Weight Loss Resistance
Blood Sugar Dysregulation
Dyslipidemia & High Cholesterol
Cardiometabolic Syndrome
Inflammation & CVD

Or Other Health Problems Like

Abdominal Pain.
Abdominal Discomfort.
Gastrointestinal Tract.
Bowel Habits/ Bowel Movements.
Digestive Health/ Digestive System.
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Why The Real Gut Doctor

With more than two decades of experience, Dr. Mark stands as a seasoned expert in the field of holistic health and well-being. His life's work is to help patients not only recover their health but also enhance their mental clarity, physical vitality, and overall quality of life.

Dr. Mark's primary focus lies in the profound influence of gut health on one's overall well-being, successfully guiding countless individuals on transformative journeys to optimal health.

Dr. Mark's approach to healing is deeply personalized, recognizing that each person's health journey is unique.

His comprehensive methodology encompasses a holistic blend of strategies, including tailored dietary plans, specialized supplements, lifestyle adjustments, and the strategic use of peptides and other anti-aging therapies.

One of Dr. Mark's most remarkable qualities is his ability to provide renewed hope and solutions to those who have previously sought medical assistance without the desired results. 

Whether you are looking to address cardiometabolic, hormonal, and digestive issues and regain your energy, edge, and peak performance, Our team is here to guide and support you every step of the way with a comprehensive, integrative approach.


The Real Gut Doctor Roadmap

At our core, we're here for the 40s, 50s, and beyond crew who are dealing with cardiometabolic, hormonal, and tummy troubles.

What's our mission?

To help you rediscover your spark, regain that competitive edge, and be at the top of your game, so you can savor a well-rounded life while looking and feeling your best.

The best part?

No need for drastic lifestyle changes or a never-ending prescription pill regimen.

This infographic outlines three phases

Personalized care focused on the root cause of your chronic health issues so you can finally feel empowered about your health.

Treat The Root Issue

We look at the whole person to determine the root cause of your chronic health concerns starting with your gut health.

Feel Like Yourself Again

Within a relatively short time, most clients regain their energy, drive & focus – so they can look and feel their absolute best!

Experience True Healing

When you take an integrative approach, you can experience significant healing that will last a lifetime.

Getting Started Is Simple

We are here to help you regain your energy, edge and peak performance so you can enjoy a well-balanced, productive life looking and feeling your absolute best… without extreme lifestyle changes or lifelong dependence on prescription drugs!

Step 1

Download our comprehensive guide on how to resolve chronic digestive & hormonal issues without endless drugs and extreme diet changes... 

Step 2

If you want to get crystal clear on the exact next steps you should be taking, schedule a free 15-minute conversation!

Step 3

Schedule your first appointment, putting you back on the path to lasting, vibrant health.

Meet Our Team

Our collaborative care approach focuses on building lifelong health skills that serve you and your entire family – supported by our experienced team who has helped people just like you.

We are dedicated to empowering you regarding gut health, improved energy, weight loss, chronic conditions, and more.

We can help you age with more vitality and teach you how to adapt your lifestyle, habits, and environment for optimal wellness that lasts a lifetime. Can you imagine a life where you feel great every day?

Learn More


  • A woman with curly hair, wearing a blue top, smiles warmly.

    My mother had brain surgery 4 years ago and ever since then, it's been a battle to find her a specialist who can recommend supplements that can help her heal without prescription drugs. We made a functional medicine appointment for her with Dr. Mark and he immediately knew what to recommend for her. This is the first time in 4 years that my mother did not have a bad reaction to the new supplements she tried and she actually says that she feels better when she takes them. For my family, this is great because it's one step closer to helping her body heal without prescription drugs and this has been a 4-year battle. I just stocked up on supplements for her actually. It's the perfect combination. This place has its own supplement line which is awesome!

    Sweeta B.
    San Ramon, CA
    A patient since 2020-currently
  • A man with short gray hair is smiling and looking slightly.

    Over the years I've visited many medical practices, with varying approaches to getting to the source of the health problem, vs. those that only treat the symptom without addressing the causes (i.e. Hospitals, Kaiser, etc... ) Dr. Jeffrey Mark and Dr. Fran are by far the most knowledgeable, smart, and technologically forward-thinking practicing practitioners in the Bay Area. They use so many state-of-the-art tools. They're constantly going to conferences to learn about all the emerging ways to really help people to be healthy; much more so than most doctors. They really know how to interpret lab values - using cutting-edge, sophisticated lab analytics - to determine all the contributing factors involved- to come up with a very complete and comprehensive way to not only fix my health problems and symptoms but also get to the root of why and all the contributing elements to the problem. I am so pleased and happy with trusting my health with everyone at All Functional Health. Every visit I feel like they truly care about helping me get better.

    Robin O.
    San Francisco, CA
  • A woman with straight brown hair and bangs smiles .

    I'm so incredibly impressed with his Dr. Mark’s attention to detail and efforts to really get to the root cause of what was wrong. He's careful to take time with each patient and really listens to what is going on. Then he carefully decides the action plan, carefully selects the types of tests he needs to run to identify the root of the problem, and utilizes the information to get his patients well from the inside out. You can tell he genuinely cares about his patients and deep down he IS genuinely a good person. So many other GI doctors just want to prescribe their patient's many medications to cover up the problems. Dr. Mark really wants to get you better! And the staff is always friendly and helpful. They go above and beyond for their patients and it makes a world of difference! Thank you!!!

    Kate P.
    San Carlos, CA
    A patient since 2019-currently
  • A bald man with a gray beard and mustache smiles broadly.

    I needed a new gastroenterologist to help manage my ulcerative colitis. I've seen Dr. Mark twice and he is one of the best M.D.s I've ever seen. He has suggested tests Dr. Lane never imagined to better titrate my meds and manage my disease. He is very smart, and upbeat and seems to take a personal interest in making sure my UC doesn't flare up and that the Side Effects of my medications are managed appropriately. Dr. Mark has taken a more holistic approach to my UC and suggested some dietary restrictions. They have worked miraculously and I am now off prednisone for longer than I have been in the past 8 years. I highly recommend him.

    Mike K.
    Walnut Creek, CA
    A patient since 2016-currently


Reclaiming Peak Health & Performance

Ditch The Digestive Distress & Regain Energy, Drive & Peak Performance


Identify The Cause Of Your Health Struggles

Understand If You Gut Or Hormonal Imbalances Are To Blame
Take The Quiz

Take The First Step Today On Your Journey Back To Health

Do you have questions about starting your path back to health? Our patient coordinator is standing by, happy to answer any questions you have to determine if our approach is right for you.


About The Real Gut Doctor

Known for his successful approach towards chronic digestive and wellness issues, Dr. Jeffrey Mark, M.D. and his team at The Real Gut Doctor combine an integrative, functional medicine approach informed by advanced lab testing.

Our unique approach to diagnosing and resolving chronic health issues recognizes that lasting health depends on resolving the underlying root causes of your symptoms. Click here to learn more »

Your Next Steps

After you have reviewed the information on our website and in our downloadable guides, we’d love to hear from you – to answer more specific questions about our approach and track record. Simply apply for a free discovery call with our patient coordinator at (925) 736-9828 or via our online appointment scheduler.

Areas Served

The Real Gut Doctor is based in San Ramon and Turlock, CA, and serves patients internationally as well as throughout the Bay Area and California. These areas include but are not limited to Palo Alto, Menlo Park, Atherton, Los Altos, Woodside, Portola Valley, Los Gatos, Hillsborough, Burlingame, Carmel Valley, San Francisco, Pacific Heights, Presidio, Marina, Danville, Blackhawk, Diablo, Pleasanton, Alamo, Walnut Creek, Lafayette, Orinda, Piedmont, Berkeley, Marin County, Santa Clara County, Napa Valley, Sonoma, Oakdale, Sacramento County, Lake Tahoe/Incline, etc.

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