Emerging research is revealing how the microbiome not only affects digestion, but joint, skin, cardiovascular and immune health. Numerous studies also suggest that the health of our microbiome determines whether we are lean or obese.
Here are some of the latest findings that scientists have discovered about the microbes that live on and in us.
Crohn’s Disease. A 2014 study showed that the community of bacteria that live in the human gut is radically altered in patients with Crohn’s disease. Patients with Crohn’s have less diversity among their intestinal bacteria than healthy individuals. And, certain types of harmful bacteria appear to be increased while healthy bacteria are decreased.
Colon Cancer. A 2013 study found that people who have a less diverse population of bacteria in their gastrointestinal tracts may be at greater risk of getting colorectal cancer. Samples from people who had colon cancer had less bacterial diversity compared with samples from healthy individuals.
Irritable Bowel Syndrome (IBS). Recent findings suggest that IBS is linked to clearly detectable gut microbiota alterations. There is a lot of evidence showing that IBS is associated with an imbalanced composition of the gut microbiota.
A 2013 study linked intestinal bacteria to rheumatoid arthritis. Research showed that patients newly diagnosed with the condition had higher levels of the bacteria P. copri than healthy individuals or patients who were undergoing treatment for a chronic condition. Here, too, overabundance of this bacterium was associated with increased inflammation and lower levels of beneficial bacteria.
Sensitive Skin. A 2014 study found daily supplementation with probiotics could help calm sensitive skin. Participants in the probiotic group showed a clinically significant reduction in skin sensitivity after 2 months of supplementation.
Infant Skin Eczema. A 2012 study found that children given probiotics may develop fewer and less severe skin problems related to atopic dermatitis, a form of eczema that affects about 20% of infants and young children, making it the most common chronic inflammatory skin disease.
Acne. A 2010 study showed that a lactoferrin-enriched fermented milk improved acne by reducing total lesions and sebum content in young adults with moderate acne. A 2013 study showed that genetic differences between strains of acne bacteria mean not all acne bacteria are bad. A few strains that were present in about 20% of the acne-prone participants were absent from the acne-free individuals.
A 2014 review of studies, found that taking probiotics for an extended period may help to reduce blood pressure. Upon evaluation, researchers found that compared to participants given a placebo or nothing at all, those taking probiotics significantly lowered systolic blood pressure and diastolic blood pressure.
Research over the past decade demonstrates that microbes in the gut not only digest food, but govern appetite, control metabolism and influence cravings. In fact, microbes in the gut can manipulate appetite regulating hormones, determining how quickly you become satiated or feel full after a meal.
Influence Cravings. A 2014 study suggests that the microbes in our gastrointestinal tract may control our moods and cause our cravings. After conducting a review of the scientific literature, researchers found that instead of simply surviving off the nutrients we eat, gut bacteria make us crave the nutrients they need to flourish.
Energy Extraction. Bacteria help us to digest food. Yet, some bacteria are more efficient at doing this, extracting more calories from the foods we eat and store them. Clinical studies demonstrate that some bacterial species promote obesity while others promote leanness.
Allergies & Asthma
A 2013 study suggested that exposure to pets in early childhood may lead to changes in gut bacteria that help prevent asthma and allergies.
All of this intriguing work reinforces the importance of microbial diversity; as a diverse ecosystem is generally more resilient. People with large and diverse bacterial populations in their digestive tracts tend to be less prone to obesity, immune problems and other health issues than people with low microbial diversity. Unfortunately, our microbiome is becoming less diverse and scientists believe the Western diet and antibiotics are to blame.
David H. Rahm, M.D. is the founder and medical director of The Wellness Center, a medical clinic located in Long Beach, CA. Dr. Rahm is also president and medical director of VitaMedica. Dr. Rahm is one of a select group of conventional medical doctors who have education and expertise in functional medicine and nutritional science. Over the past 20 years, Dr. Rahm has published articles in the plastic surgery literature and educated physicians about the importance of good peri-operative nutrition.