In my last post, I discussed the “gut-brain-skin” axis theory—which suggests that what we eat, what lives in our gut, our mood and the health of our skin are all intimately related.

In the 1930’s it was popular to treat acne internally with the use of L. acidophilus and L. acidophilus –fermented milk products, though there was little research into this approach and interest waned despite its apparent effectiveness.  More recently, studies have shown that many patients with acne vulgaris and acne rosacea have low stomach acid (hypochlorhydria), small intestinal bacterial overgrowth (SIBO) and disturbances in normal gastrointestinal microflora.  In 1961, a physician by the name of Robert Silver conducted a study in which he orally administered L. acidophilus and L. bulgaricus—and showed that 80% of the 300 patients studied had some degree of clinical improvement in their acne.  Since that time, advances in molecular biology have shown that probiotics can regulate the release of inflammatory cytokines within the skin, including substance P—which may be a primary mediator of inflammation and sebum production in acne.  Both Bifidobacterium longum and Lactobacillus paracasei can reduce the inflammation mediated by substance P.  Certain bacterial strains such as Streptococcus salivarius secrete substances with antimicrobial properties, which limit the growth of Propionibacterium acnes, thought to play a major role in the development of acne lesions.

Probiotics may also act in the “gut-brain-skin” axis via glycemic control.  New research shows that gut flora contribute to glucose tolerance—for example, Bifidobacterium lactis improved fasting insulin levels and glucose turnover rates.

Of note, milk may play a role in acne development via insulin-like growth factor 1 (IGF-1), which is absorbed across colonic mucosa but reduced in fermented dairy products.  Thus, avoidance of milk (and substituting fermented milk products such as cheese, yogurt, kefir) may help improve acne in some patients.

More research is forthcoming with regard to the specific molecular mechanisms at play, but so far the evidence is quite compelling that dietary changes and modification of gut microflora can have an impact on skin inflammation and acne.

TIP:  A topically applied yogurt mask (which contains the lactic acid bacteria Streptococcus thermophilus) can increase ceramide production—which have activity against P. acnes and a direct anti-inflammatory effect.

BOTTOM LINE:  Acne may respond to changes in diet (increased fermented dairy consumption and nutrient rich foods; reduce sugar, carbohydrates, processed foods) as a result of normalization of gut microbiota.


PROBIOTICS and your mood

How does diet affect our mood?

Some scientists believe that what we eat encourages certain types of microbes to thrive in our gastrointestinal tract, and these microbes can affect our mood, skin, weight, immune system and risk for chronic diseases such as autoimmune disease and cancer.  The “gut-brain-skin” theory has been around since 1930 when dermatologists John H. Stokes and Donald M. Pillsbury noted that skin conditions such as acne are often associated with mood disorders and gastrointestinal disturbances—which increase gut permeability and lead to systemic inflammation.

Since the 1930’s, animal and human research has supported the idea that mental health disorders are frequently associated with low levels of Lactobacillus and Bifidobacterium, an omega-3 deficient diet and low stomach acid (hypochlorhydria).  The microflora of our GI tract is intimately involved in gut permeability—which when breached can allow foreign proteins across the gut’s barrier and trigger immune reactions and systemic inflammation, leading to inflammatory acne lesions and depressed mood/ anxiety.  In fact, it has been shown in animal studies that a circulating endotoxin, E. coli lipopolysaccharide (LPS)—which is usually not present in blood but can be if the intestinal barrier is not working proprerly—can itself produce depression-like behavior in animals.  In addition, if the gut is not populated with beneficial microbes (or they’re not in the appropriate location), small intestinal bacterial overgrowth (SIBO) can result—which has been associated with fibromyalgia, chronic fatigue syndrome, constipation, depression and anxiety.  One cause of this disturbance of normal gut microflora is hypochlorhydria, sometimes caused by medication (e.g. proton pump inhibitors, H2 blockers), hypothyroidism, atrophic gastritis, naturally occurring with age, or other less common conditions such as tumors, mucolipidosis or pellagra (niacin deficiency).

Probiotics including Lactobacillus and Bifidobacterium species have been shown to limit systemic oxidative stress and reduce inflammatory cytokines in various tissues of the body, inhibit the release of substance P and decrease monoamine oxidase activity—resulting in decreased anxiety- like behavior in animals.  Stress hormones and substance P are known to cause anxiety, depression and aggression.  The addition of probiotics to lab animal feed increases tissue levels of omega-3 fatty acids, peripheral tryptophan levels, and increase serotonin and dopamine turnover in the frontal cortex and limbic system—which can have a positive impact mental health.

This “gut-brain-skin” theory also works in reverse—stress and anxiety can adversely affect the gut microflora, as can a poor diet.  In the Western diet, which is typically high in fat, sugar as well as processed foods, the loss of Bifidobacteria can lead to increased intestinal permeability, encroachment of LPS endotoxins through the intestinal barrier, low grade inflammation, insulin resistance and mood disorders.  As we learn more about the prebiotic-probiotic-mood relationship, perhaps physicians will consider treating mood disorders with a prescription for a certain diet or HCl supplement, as opposed to a psychopharmaceutical drug.

BOTTOM LINE:  Prebiotics and probiotics can have a positive impact on mood.  Anyone who wishes to lead a healthier lifestyle and promote a normal mood state should eat a healthy diet and consider consuming fermented dairy products daily (see PROBIOTICS overview).


The concept of probiotics—live microorganisms which when administered in adequate amounts confer a health benefit to the host—is not new.  It has only been recently that the scientific community has taken a closer look at probiotics and their practical applications.  There are too many areas under investigation to discuss, so here’s a brief list of possible uses of probiotics in the medical arena (the items at the top of the list have more supporting evidence than the more speculative/ uncertain items toward the end):

• Infectious diarrhea (antibiotic associated, rotavirus, c. diff, traveller’s)

• Irritable Bowel Syndrome (IBS)

• Lactose intolerance

• Hyperlipidemia

• Small intestinal bacterial overgrowth (post op gastric bypass or Crohn’s Disease)

• Helicobater pylori

• Bacterial vaginosis

• Necrotizing Enterocolitis (NEC) in pre-term infants

• Colon cancer (prevention and possibly treatment)

• Metabolic syndrome (obesity, hyperlipidemia, hypertension)—and thus type 2 diabetes and coronary artery disease

• Dermatologic conditions: acne, rosacea

• Inflammatory Bowel Disease (IBD)–Crohn’s Disease and Ulcerative Colitis

• Prevention of the common cold

• Hypertension (high blood pressure)

• Hepatic encephalopathy (due to liver disease)

• Nursing Home Care: decreased febrile episodes, reduced constipation and diarrhea, reduced MRSA

• Autoimmune disorders—such as multiple sclerosis, Type 1 Diabetes (still under investigation; demonstrated in mice)

• Allergic conditions—food allergies, atopic dermatitis (still under investigation)

• Anxiety, depression (still under investigation)

Though it might seem like wishful thinking that these bacteria can be so helpful, it makes absolute sense.  Humans have evolved with these bacteria living symbiotically inside our guts, which have come to serve as an organ within an organ—aiding digestion, improving nutrient absorption, warding off infection, regulating gut permeability, and modulating the host’s immune system.   As a result of our modern industrialized society, practices such as surgical childbirth, use of pasteurized food products, synthetically supplemented food, cleaner homes, overuse of antibiotics, etc. have affected the microenvironments on our skin and in our gastrointestinal tract.  This may very well be contributing to the surge in modern diseases such as diabetes, allergies and autoimmune disorders that we are currently witnessing.

Note:  the relationship between host and gut microflora is extremely complex and the strains of bacteria studied for the above conditions are very specific.  Much of the research thus far has investigated Lactobacillus and Bifidobacterium species.   If you were interested in incorporating probiotics in your daily life, you may consider adding fermented milk products (such as yogurt or kefir with live active cultures) to your diet.   These usually contain many beneficial strains of bacteria including L. acidophilus, B. bifidus, S. thermophilus, and are generally regarded as safe.

BOTTOM LINE:  We have been big yogurt fans for years, but have added homemade kefir to our diet.   Making your own kefir is very simple and has no added sugars–you can flavor with banana & strawberry or other fruit in a smoothie.  Many websites walk you through the process and have great tips & videos, including: and .  There are also many online sites where individuals offer kefir grains for free–look for a local donor.  Tips:  avoid using any metal(spoons, strainers) and avoid ultra- pasteurized milk (use pasteurized milk instead).

GERD the solution

Desperate parents take desperate measures if their children are suffering.  My daughter who had gastroesophageal reflux disease (GERD) for years was truly suffering, mostly as a result of the medical treatment she had been receiving—namely the PPIs (proton pump inhibitors Prilosec and Prevacid).  She had not been sleeping, she could barely focus in school, was experiencing daily headaches, caught every virus that went through school, had a poor appetite and then developed diarrhea.  After discontinuing the PPI, she became a new person—full of life, color in her cheeks, cheerful mood and had a healthy appetite once again.  I decided to never, ever give anyone in my family that class of medication again!

But what about the reflux?  I became a dietary tiger mom and took away her precious pasta, bread and sugar.  Within four days, her gastrointestinal symptoms were gone—no more bloating, gas, abdominal discomfort, and no reflux.  Her energy was also improved.  I kept track of all that she ate in a diet journal, tracking her emotions, energy, GI symptoms and clearly noticed that when she ate pasta, bread or sugar her reflux symptoms returned.  She has maintained the reflux free diet quite well and has only complained a few times when birthday cake or another special occasion arises.  She knows very well at the age of 9 that if she were to eat these foods, she will suffer the consequences.  Of course, I changed the way our entire household ate—pretty much eliminating pasta and bread (and both mom and dad have lost a few pounds as a result of that change alone!).  Large piles of fruit and vegetables have taken over our kitchen and smoothies have become a regular treat for all of the kids.

As a result of my attempts to adopt a mostly vegetarian diet in our family (for health and environmental reasons), I had accidentally shifted my daughter’s diet to include primarily pasta and whole grains. In order to set things right, I acted in defiance of the USDA’s food pyramid schema—and prioritized fruit, vegetables, fish, meat and some dairy while minimizing grains.  This worked like a charm for her and she continues to feel healthy and happy, reporting no reflux at all!  I’m not certain why this approach worked, but based on what I’ve read in recent scholarly medical articles on the subject, I believe that she had a perfect storm:  excess refined carbohydrates (daily pasta, bread, sugar) and acid suppression.  This may have resulted in overgrowth of unfavorable bacteria in her gut and malabsorption, and possibly vitamin/mineral deficiency exacerbating matters.  Luckily, these all seemed to resolve with elimination of certain carbohydrates (specifically breads, pasta, crackers) and probiotics to repopulate her gut with favorable microflora.

Of note, my daughter did have negative tests for gluten sensitivity (Endomysial IgA, Transglutaminase IgA)–but she may have Celiac Disease or non- Celiac gluten sensitivity…we’ll see.

To read more, look for GERD evidence for the solution and a future entry on PROBIOTICS.