Chronic skin problems and mental health disorders often occur together, and acne vulgaris is a skin problem often associated with depression and anxiety. Acne patients often have gastrointestinal problems, such as constipation, halitosis and gastric reflux. Intestinal bacteria may a role in skin problems and in emotional reactions, and beneficial bacteria can be therapeutic in these cases.
In the 1930’s, the ‘gut-brain-skin unifying theory’ was posed by dermatologists, John H. Stokes and Donald M. Pillsbury. They found that emotions altered gastrointestinal function and the number of microbes in the intestines, thereby altering systemic inflammation. They believed these three systems influenced each other. Stokes and Pillsbury found that most patients with acne vulgaris had constipation. A 2005 study showed the fecal concentrations of Lactobacillus and Bifidobacterium were ‘significantly’ lower in patients with constipation than in normal controls and they had more intestinal permeability. The Western diet, high in sugar and fat and low in fiber, is associated with a high risk of acne and low levels of Lactobacillus and Bifidobacterium.
Forty percent of people with acne have low stomach acid levels, which would change the kinds of bacteria which survive to enter the intestines. Alterations of intestinal flora changes intestinal permeability with development of systemic and local skin inflammation. Stokes and Pillsbury advocated the use of Bacillus acidophilus and cod liver oil as sources of probiotics and omega-3 fatty acids. (Fermented milk products were commonly used in the 1930s to treat acne.) Even today, “The theoretical value of oral probiotics as adjuvant care in acne vulgaris seems sound”.
Studies continue to show that low levels of stomach acid (hypochlorhydria) results in small intestinal bacterial overgrowth (SIBO). Antibiotics and long-term proton pump inhibitors (antacids) result in SIBO also. SIBO can be asymptomatic or can cause malabsorption syndrome. It also can cause bloating, diarrhea, abdominal pain and constipation. The interference of bacteria in digestion can cause deficiencies of protein, carbohydrates, fats, B vitamins, etc. SIBO causes increased intestinal permeability, and is associated with depression and anxiety. Treatment of SIBO can relieve the emotional and skin symptoms. Probiotics and omega-3 can treat both the physical and the emotional symptoms.
Stress of many types has been shown to alter levels of intestinal flora. Stress reduces the numbers of Lactobacillus and Bifidobacteria species. Bacteroides spp. were increased in acne patients, and have been found in people who are stressed.
Topical probiotics have been found to be useful for acne vulgaris. Streptococcus thermophilus, as found in yogurt, seems to work against Propionibacterium acnes (P. acnes). An oral bacterium, Streptococcus salivarius can inhibit P. acnes.
People with mental health problems often have low levels of Lactobacillus acidophilus. Saccharomyces cerevisiae improves acne vulgaris and constipation. Feeding food with probiotics in the laboratory has been shown to increase tryptophan in the body, and alters serotonin and dopamine turnover in the brain. The probiotics even increased blood levels of omega-3 fatty acids.
Insulin resistance results in increased risk of depressive symptoms. Treatment with Bifidobacterium lactis normalizes insulin levels.
Unfermented milk consumption is associated with acne, perhaps, because it contains natural and synthetic growth hormones. Fermented milk products, such as yogurt, are therapeutic for acne.
Treatment of patients with mood disorders using Lactobacillus casei have shown improvements in depression and reduced anxiety. A combination of daily Bifidobacterium longum and Lactobacillus helveticus improved depression, anxiety and anger scores as well as lowered blood levels of cortisol (an indication of reduced stress). Prebiotics reduce stress levels and increase fecal levels of bifidobacteria. The soil organism, Mycobacterium vaccae, improved mood scores in lung cancer patients on chemotherapy.
CONCLUSION: Many questions about the gut-mood-skin triangle remain to be solved by further studies. Stokes and Pillsbury continue to be found to be correct that friendly bacteria from the gastrointestinal tract are therapeutic in acne and in mood disorders such as anxiety and depression.
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