Kiri Cole
CERTIFIED WELLNESS COACH AND NUTRITION CONSULTANT




Making you healthier one meal at a time 



Gut Flora: The Hidden Key to Health and Wellness - Part 2

Gut Flora: The Hidden Key to Health and Wellness – Part 1 introduced intestinal germs and the avenues through which they colonize the gastrointestinal tract during and succeeding childbirth. The article explained that compared to a baby birthed vaginally and breast-fed, an infant delivered via Cesarean section and given formula develops gut flora or intestinal microbiota that is less rich and diverse, weakening the baby’s immune system and making the child more vulnerable to disease. Despite this grim revelation, Part 1 concluded with the assertion that in spite of a mother's decisions, diet can help create healthy intestinal microbial communities later in life. 

This post, Part 2, explores the relationship between diet and the bugs within you.

As mentioned in Part 1, gut flora profoundly impacts your health and well-being through its metabolic functions, role in the immune system, and ability to maintain internal homeostasis. Please see the summary below:

Metabolic Activity:

 • Breaks down carbohydrates, such as fruits and vegetables
 • Supports nutrient absorption
 • Synthesizes short chain fatty acids
 • Produces vitamins

Immune System Functions and Homeostasis:

 • Trains the immune system to distinguish between harmless and pathogenic bacteria
 • Stops the colonization of destructive microorganisms that breed disease
 • Facilitates the growth and development of white blood cells (immune cells)
 • Protects against various maladies as Inflammatory Bowel Syndrome (IBD)
 • Maintains intestinal homeostasis to prevent sickness

Dysbiosis and Diet

Healthy and balanced intestinal microbiota beget vitality. Dysbiosis, or microbial imbalance, generates sickness. According to Dr. Leo Galland, MD, board certified internist, celebrated author, and founder of the Foundation for Integrative Medicine, “Intestinal dysbiosis should be considered as a mechanism promoting disease in all patients with chronic gastrointestinal, inflammatory or autoimmune disorders, food allergy and intolerance, breast and colon cancer, and unexplained fatigue, malnutrition or neuropsychiatric symptoms.” Environmental factors, such as method of childbirth, antibiotics, stress, and diet alter the gut flora and instigate dysbiosis. This article focuses on diet, as it is the biggest determinant of intestinal microbiota health following method of childbirth. 

In fact, diet impacts the gut flora’s composition as early as infancy. Research shows that a breast-fed baby’s intestinal microbiota contains more gut barrier-protecting bacteria, called Bifidobacteria, than a formula-fed infant’s flora, which exhibits higher levels of different intestinal bugs, such as Bacteroides, Clostridium coccoides, and Lactobacillus. 

Diet Generates Dysbiosis Which Produces Disease 

From birth to old age, diet continues to alter the gut flora. As the forthcoming studies will demonstrate, wholesome eating habits establish and nourish diverse, balanced microbiota that executes its metabolic and immune functions effectually. On the other hand, the typical western diet–abundant in deleterious fats, processed carbohydrates, refined sugars, and toxic, synthetic additives–generates dysbiosis, which leads to obesity and other associated maladies. 

The following studies published by the National Institutes of Health and The Journal of the Federation of American Societies for Experimental Biology clarify the connection between diet, dysbiosis, and disease, specifically obesity. So, before you relish those tempting, soft-baked cookies or enjoy that mouth-watering burrito for lunch, read this!

Study 1: "Western" Eating Habits Establish Dysbiosis

Researchers weaned genetically identical mice on a low-fat, plant-based (PB) diet and then divided these mice into two groups, one that continued to eat a PB diet and another that switched to a “Western” diet, high in saturated and unsaturated fats, carbohydrates, and human food additives, such as corn starch. The mice following “Western” eating habits gained significant weight, developed greater adipose tissue, lost intestinal microbial diversity, and suffered dysbiosis. Evidently, a “Western” diet engenders weight gain and imbalances the intestinal microbiota. However, is it the diet or the microbiota that ultimately triggers obesity?  







Study 2 and 3: The Middle Man Between "a Moment on the Lips and a Lifetime on the Hips" 

The following model was employed to solve this question. Researchers surgically altered mice, removing their intestinal microbiotas, to spawn germ-free (GF) rodents. Subsequently, the scientists transplanted either “obese” or “lean” microbiotas harvested from rodents that had been weaned on a “Western” or PB diet, respectively, into these GF mice. After the transplant, all mice ate a PB diet. Note that when a GF mouse receives gut flora, the mouse's body fat naturally increases, as one of the flora’s metabolic functions involves facilitating and regulating fat storage. Accordingly, all study subjects experienced weight gain. Nevertheless, the mice with “obese” gut floras gained nearly 50% more weight than those with “lean” floras. This proves that notwithstanding eating habits, an “obese” intestinal microbiota induces weight gain more so than a “lean” one. Evidently, the gut flora’s composition itself triggers obesity. This is further confirmed by research revealing that GF mice do not become obese when eating a HF diet. Therefore, a HF diet astonishingly does not cause fatness in the absence of gut flora.

Now, I know what you are pondering. What surgeon will remove my intestinal microbiota so that I never gain an extra pound again? However, considering the microbiota's vital role regarding metabolism and immunity, I would skip the operating room and head to an organic market instead.  

My digression aside, you now know that a high-fat, nutrient-deficient diet adulterates the gut flora, engendering dysbiosis and producing obesity. The question remains whether eating healthily can reverse this harmful microbial imbalance and resultant diseased state. 

Study 4: Adopting a Healthy Diet Recalibrates the Microbiota

Here is the answer! Scientists raised obese mice that were weaned on a “Western” diet. They took a subset of these rodents and changed their eating habits to a low carbohydrate (LC) or low fat diet (LF). Compared to the mice maintained on the “Western” diet, those following the LC or LF diet consumed fewer calories and gained less weight and total body fat. Additionally, the LC and LF diets rebalanced and diversified the mice’s intestinal microbial communities. 

Diet to the rescue! Plus, you moms finally receive a “get-out-of-jail free card.” Your kids can no longer use your birthing and child-rearing decisions as a scapegoat for their every ache and pain. Yahoo!!!  

Quick Running Synopsis with Additional Insights

Evidently, diet modifies the intestinal microbiota, which is intrinsically involved in varied metabolic and immune system activities, as aforementioned and demonstrated. Insalubrious eating habits produce microbial imbalances that consequently create internal toxicity that triggers chronic inflammation, which leads to obesity and other associated maladies. 

Gut Flora, Obesity, Diabetes, and More Examined: Diet Trumps Genetics!!! 

Yes, as incredulous as it may sound, with regard to gut flora, diet determines wellness more so than genetics. The ISME Journal (Multidisciplinary Journal of Microbial Ecology), published a study involving mice that were fed either a high fat (HF) diet or normal chow (NC). After 25 weeks, the mice eating the NC were healthy, with normal weight and glucose tolerance. The mice consuming the HF diet became obese and exhibited impaired glucose tolerance. Examining both groups’ intestinal microbiotas revealed that diet explained 57% of the microbial differences while genetics only accounted for 12%. The HF fed mice’s gut floras suffered dysbiosis, which caused the aforementioned excessive weight gain and pre-diabetic state. The gut flora’s role in type 2 diabetes is further cemented by research indicating that GF mice consuming a HF diet are not susceptible to diet-induced insulin intolerance like those mice with gut flora’s are.



Humanized Models Provide the Same Results

I realize that the aforesaid study participants all have 4 legs. Therefore, you may be wondering whether human intestinal microbiota’s operate differently. With this in mind, scientists created humanized mouse models, in which fecal matter from a healthy human was transplanted into a GF mouse that was weaned on a PB diet. Consequently, a replica of the human’s intestinal microbiota developed in the rodent. After switching the mouse to a “Western” diet–high-fat and high-sugar–dysbiosis and obesity resulted. 

Human studies reproduced these outcomes.  

A Clear Connection Between Diet and Gut Flora

Diet clearly has a dominant role in shaping the intestinal microbiota. Changes to its composition fueled by deleterious eating habits causes dysbiosis and as such transform the gut flora into a pathogenic-entity that leads to the development of obesity, type 2 diabetes, and other closely associated conditions as high blood pressure and elevated cholesterol levels, all of which precipitate cardiovascular disease. Other maladies influenced by the intestinal microbiota include irritable bowel syndrome, inflammatory bowel syndrome, various allergies, and more. 

Wrap-up: Stay tuned for Part 3, which will detail the foods that promote healthy intestinal microbiota!





References:
http://www.healthy.net/Health/Article/Intestinal_Dysbiosis_and_the_Causes_of_Disease/423/1
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3448089/
http://www.nature.com/ismej/journal/v4/n2/full/ismej2009112a.html
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3687783/
http://www.fasebj.org/content/24/12/4948.long
http://www.ncbi.nlm.nih.gov/pubmed/17699621
http://stm.sciencemag.org/content/1/6/6ra14.long
http://diabetes.diabetesjournals.org/content/56/7/1761.long
http://www.jci.org/articles/view/25102
http://www.ncbi.nlm.nih.gov/pubmed/17823788?dopt=Abstract&holding=npg